TOREX XC9235, XC9236, XC9237 User Manual

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XC9235/XC9236/XC9237

Series

ETR0514-012

600mA Driver Tr. Built-In, Synchronous Step-Down DC/DC Converters

■GENERAL DESCRIPTION

The XC9235/XC9236/XC9237 series is a group of synchronous-rectification type DC/DC converters with a built-in 0.42Ω P-channel MOS driver transistor and 0.52ΩN-channel MOS switching transistor, designed to allow the use of ceramic capacitors. Operating voltage range is from 2.0V to 6.0V (A～C types), 1.8V to 6.0V (D～G types). For the D/F types which have a reference voltage of 0.8V (accuracy: ±2.0%), the output voltage can be set from 0.9V by using two external resistors. The A/B/C/E/G types have a fixed output voltage from 0.8V to 4.0V in increments of 0.05V (accuracy: ±2.0%). The device provides a high efficiency, stable power supply with an output current of 600mA to be configured using only a coil and two capacitors connected externally. With the built-in oscillator, either 1.2MHz or 3.0MHz can be selected for suiting to your particular application. As for operation mode, the XC9235 series is PWM control, the XC9236 series is automatic PWM/PFM switching control and the XC9237 series can be manually switched between the PWM control mode and the automatic PWM/PFM switching control mode, allowing fast response, low ripple and high efficiency over the full range of loads (from light load to heavy load). The soft start and current control functions are internally optimized. During stand-by, all circuits are shutdown to reduce current consumption to as low as 1.0μA or less. The B/F/G types have a high speed soft-start as fast as 0.25ms in typical for quick turn-on. With the built-in UVLO (Under Voltage Lock Out) function, the internal P-channel MOS driver transistor is forced OFF when input voltage becomes 1.4V or lower. The B to G types integrate C via the internal discharge switch located between the L quickly returns to the V Three t

■APPLICATIONS

●Mobile phones, Smart phones

●Bluetooth headsets

●Mobile WiMAX PDAs, MIDs, UMPCs

●Portable game consoles

●Digital cameras, Camcorders

●MP3 Players, Portable Media Players

●Notebook computers

■

●XC9235/XC9236/XC9237

D/F types (Output Voltage Externally Set)

es of package SOT-25 (A/B/C types only), USP-6C, and 0.4mm low height USP-6EL (A/B/C types only) are available.

TYPICAL APPLICATION CIRCUIT

/B/C/E/G types (Output Voltage Fixed)

discharge function which enables the electric charge at the output capacitor CL to be discharged

L

level as a result of this function.

SS

and VSS pins. When the devices enter stand-by mode, output voltage

X

■FEATURES

Driver Transistor Built-In

Input Voltage : 2.0V ~ 6.0V (A/B/C types)

1.8V ~ 6.0V (D/E/F/G types)

Output Voltage : 0.8V ~ 4.0V (Internally set)

High Efficiency : 92% (TYP.)

Output Current : 600mA

Oscillation Frequency : 1.2MHz, 3.0MHz (+15%)

Maximum Duty Cycle : 100%

Control Methods : PWM (XC9235)

PWM/PFM Auto (XC9236)

Function

Capacitor Operating Ambient Temperature

Packages : SOT-25 (A/B/C types only), USP-6C

USP-6EL(A/B/C types only)

Environmentally Friendl

■

TYPICAL PERFORMANCE CHARACTERISTICS

●Efficiency vs. Output Current（f

PWM/PFM Automatic Sw itching Control

100

90

80

VIN= 4.2V

70

3.6V

60

2.4V

50

40

30

Efficency:EFFI(%

Efficiency: EFFI (%)

20

10

0

0.1 1 10 100 1000

Output Current:IOUT(mA)

☆GreenOperation Compatible

: 0.42Ω P-ch driver transistor

0.52Ω N-ch switch transistor

0.9V ~ 6.0V (Externally set)

PWM/PFM Manual (XC9237) : Current Limiter Circuit Built-In

(Constant Current & Latching)

C

Discharge (B/C/D/E/F/G types)

L

High Speed Soft Start (B/F/G type)

:

Low ESR Ceramic Capacitor

:-40℃ ~ +85℃

: EU RoHS Com

=1.2MHz, VOUT=1.8V）

OSC

PWM Control VIN= 4.2V

3.6V

2.4V

liant, Pb Free

1/33

to other pins, it should be connected to the

XC9235/XC9236/XC9237

■PIN CONFIGURATION

Lx VOUT

5 4

VIN 6

VSS 5

CE/MODE 4

132

VSS CE/MODEVIN

SOT-25

(Top View)

Series

USP-6C

(BOTTOM VIEW)

* Please short the VSS pin (No. 2 and 5). * The dissipation pad for the USP-6C package should be solder-plated in recommended mount pattern and metal masking so as to enhance mounting strength and heat release. If the pad needs to be connected

1 Lx

2 VSS

3 VOUT (FB)

VIN 6

VSS 5

CE/MODE 4

V(No. 5) pin.

1 Lx

2 VSS

3 VOUT

USP-6EL

(BOTTOM VIEW)

■PIN ASSIGNMENT

PIN NUMBER

SOT-25 USP-6C/USP-6EL

1 6 VIN Power Input 2 2, 5 VSS Ground 3 4 CE / MODE High Active Enable / Mode Selection Pin

4 3

5 1 Lx Switching Output

2/33

PIN NAME FUNCTION

VOUT

FB

Fixed Output Voltage Pin (A/B/C/E/G types)

Output Voltage Sense Pin (D/F types)

XC9235/XC9236/XC9237

■PRODUCT CLASSIFICATION

●Ordering Information

XC9235①②③④⑤⑥-⑦ XC9236①②③④⑤⑥-⑦ XC9237①②③④⑤⑥-⑦

DESIGNATOR ITEM SYMBOL DESCRIPTION

Fixed Output voltage (V

①

Functional selection

Adjustable Output voltage (FB)

Functional selection

Fixed Output Voltage

②③

Adjustable Output Voltage

④

Oscillation Frequency

⑤⑥-⑦

(*1)

The “-G” suffix indicates that the products are Halogen and Antimony free as well as being fully RoHS compliant.

(*2)

SOT-25, USP-6EL package are available for the A/B/C series only.

(*1)

Fixed PWM control

(*1)

PWM / PFM automatic switching control

(*1)

Fixed PWM control QPWM / PFM automatic switching manual selection

A VIN≧2.0V, No CL discharge, Low speed soft-start

B VIN≧2.0V, CL discharge, High speed soft-start

)

OUT

C VIN≧2.0V, CL discharge, Low speed soft-start

E VIN≧1.8V, CL discharge, Low speed soft-start

G V

≧1.8V, CL discharge, High speed soft-start

IN

D VIN≧1.8V, CL discharge, Low speed soft-start

F VIN≧1.8V, CL discharge, High speed soft-start

Output voltage options

(V

OUT

e.g. V

)

08 ~ 40

0.05V increments: 0.05=A, 0.15=B, 0.25=C, 0.35=D, 0.45=E,

=2.8V→②=2, ③=8

OUT

V

=2.85V→②=2, ③=L

OUT

0.55=F, 0.65=H, 0.75=K, 0.85=L, 0.95=M

Reference voltage is fixed in 0.8V ②=0, ③=8

(FB)

08

C 1.2MHz

D 3.0MHz

(*2)

(3,000/Reel)

(*2)

(3,000/Reel)

Packages

(Order Unit)

MR SOT-25

MR-G SOT-25

ER USP-6C (3,000/Reel)

ER-G USP-6C (3,000/Reel)

(*2)

4R-G USP-6EL

(3,000/Reel)

Series

3/33

XC9235/XC9236/XC9237

Series

■BLOCK DIAGRAM

●XC9235 / XC9236 / XC9237

A Series

●XC9235 / XC9236 / XC9237 D/F Series

■ABSOLUTE MAXIMUM RATINGS

Power Dissipation

NOTE: The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "L" level inside,

and XC9235 series chooses only PWM control.

The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "H" level inside,

and XC9236 series chooses only PWM/PFM automatic switching control.

Diodes inside the circuit are ESD protection diodes and parasitic diodes.

PAR AMETER SYMBOL RATINGS UNIT

VIN Pin Voltage VIN - 0.3 ~ 6.5 V

Lx Pin Voltage VLx - 0.3 ~ VIN + 0.3 V

V

Pin Voltage V

OUT

FB Pin Voltage VFB - 0.3 ~ 6.5 V

CE / MODE Pin Voltage VCE - 0.3 ~ 6.5 V

Lx Pin Current ILx ±1500 mA

SOT-25 250

(*Ta=25℃)

Operating Ambient Temperature Topr - 40 ~ + 85

Storage Temperature Tstg - 55 ~ + 125

USP-6C 120

USP-6EL

- 0.3 ~ 6.5 V

OUT

Pd

●XC9235 / XC9236 / XC9237

B/C/E/G Series

120

Ta =2 5℃

mW

O

C

O

C

4/33

■ELECTRICAL CHARACTERISTICS

XC9237A18Cxx, V

OUT

=1.8V, f

=1.2MHz, Ta=25℃

OSC

XC9235/XC9236/XC9237

Series

PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNIT

Output Voltage V

OUT

When connected to external components, V

IN=VCE

=5.0V, I

=30mA

OUT

1.764 1.800 1.836 V ①

Operating Voltage Range VIN 2.0 - 6.0 V ①

V

Maximum Output Current I

UVLO Voltage V

OUTMAX

UVLO

Supply Current IDD V

Stand-by Current I

Oscillation Frequency f

PFM Switching Current I

PFM Duty Limit DTY

Maximum Duty Cycle DTY

Minimum Duty Cycle DTY

Efficiency

(*2)

EFFI

Lx SW "H" ON Resistance 1 R

Lx SW "H" ON Resistance 2 R

Lx SW "L" ON Resistance 1 R

Lx SW "L" ON Resistance 2 R

Lx SW "H" Leak Current

Lx SW "L" Leak Current

Current Limit

(*5)

I

(*5)

I

(*10)

I

Output Voltage

Temperature Characteristics

(V

CE "H" Voltage V

CE "L" Voltage V

VIN=5.0V, VCE=0V, V

STB

OSC

PFM

LIMIT_PFM

MAX

MIN

LxH

VIN=VCE=5.0V

LxL

VIN=VCE=3.6V

LxL

LeakH

LeakL

V

LIM

△V

OUT

・△Topr)

OUT

CEH

CEL

IN=VOUT(E)

When connected to external components

V

CE

Voltage which Lx pin holding “L” level

IN=VCE

When connected to external components, V

IN=VOUT(E)

When connected to external components, V

IN=VOUT(E)

VCE=VIN=(C-1), I

VIN=VCE=5.0V, V

When connected to external components, V

CE=VIN=VOUT(E)

VIN=VCE=5.0V, V

VIN=VCE=3.6V, V

VIN=V

IN=VCE

/

I

OUT

V

OUT

Voltage changes Lx to “H” level V

OUT

Voltage changes Lx to “L” level

When connected to external components,

PWM "H" Level Voltage V

PWMH

I

OUT

becomes 1020 kHz≦f

When connected to external components,

PWM "L" Level Voltage V

PWML

I

OUT

becomes f

CE "H" Current I

CE "L" Current I

Soft Start Time tSS

Latch Time t

Short Protection Threshold

Voltage

Test conditions: Unless otherwise stated, VIN=5.0V, V NOTE:

*1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100 *3: ON resistance (Ω)= (V *4: R&D value *5: When temperature is high, a current of approximately 10μA (maximum) may leak.

*6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,

control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than V

mode when the CE/MODE pin voltage is equal to or lower than V *7: Time until it short-circuits V *8: When V

*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.

*10: Current limit denotes the level of detection at peak of coil current. *11: “H”=V *12: XC9235 series exclude I

*13: XC9235/9236 series exclude V

is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.

IN

If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.

-1.2V, “L”=+0.1V~-0.1V

IN~VIN

- Lx pin measurement voltage) / 100mA

IN

PFM

VIN=VCE=5.0V, V

CEH

VIN=5.0V, VCE=0V, V

CEL

When connected to external components, V

CE

V

LAT

IN=VCE

Short Lx at 1Ω resistance Sweeping V

V

SHORT

1Ω resistance, V “L” level within 1ms

OUT(E)

with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.

OUT

and DTY

PWMH

because those are only for the PFM control’s functions.

LIMIT_PFM

and V

because those are only for the XC9237 series’ functions.

PWML

+2.0V, VCE=1.0V,

=VIN, V

OUT

=0V,

OUT

=5.0V, V

OUT=VOUT(E)

+2.0V, VCE =1.0V, I

+2.0V, VCE =VIN, I

OUT

OUT=VOUT(E)

+1.2V, I

OUT

(*4)

- 0.45 0.65 Ω ④

(*4)

×1.1V - 15 33 μA ②

OUT=VOUT(E)

=1mA

×1.1V - 0 1.0 μA ②

=100mA

OUT

=1mA

OUT

(*12)

200 300 % ①

×0.9V 100 - - % ③ ×1.1V - - 0 % ③

=100mA

OUT

=0V, ILx=100mA

=5.0V, VCE=0V, Lx=0V - 0.01 1.0 μA ⑤

=5.0V, VCE=0V, Lx=5.0V - 0.01 1.0 μA ⑤

=5.0V, V

OUT=VOUT(E)

×0.9V

(*9)

(*1, *11)

(*12)

(*3)

- 0.35 0.55 Ω ④

(*3)

- 0.42 0.67 Ω ④

(*8)

900 1050 1350 mA ⑥

=30mA, -40℃≦Topr≦85℃ - ±100 -

=0V, Applied voltage to VCE,

=0V, Applied voltage to VCE ,

(*6)

=1mA

=0V → VIN, I

, Voltage which oscillation frequency

OSC

(*6)

, Voltage which oscillation frequency

＜1020kHz

OSC

=0V - 0.1 - 0.1 μA ⑤

OUT

=0V - 0.1 - 0.1 μA ⑤

OUT

=1mA

=5.0V, V

OUT

=0.8×V

OUT

, VIN=VCE=5.0V, Short Lx at

OUT

voltage which Lx becomes

OUT

(*11)

≦1380kHz

(*13)

,

OUT(E)

(*7)

(*13)

600 - - mA ①

1.00 1.40 1.78 V ③

1020 1200 1380 kHz ①

120 160 200 mA ①

- 92 - % ①

- 0.52 0.77 Ω -

ppm/

0.65 - 6.0 V ③

V

- 0.25 V ③

SS

- - V

–

V

IN

0.25

- 1.0 V ①

IN

- - V ①

0.5 1.0 2.5 ms ①

1.0 - 20.0 ms ⑦

0.675 0.900 1.150 V ⑦

=Nominal Voltage

minus 0.3V, and to the PWM

minus 1.0V and equal to or greater than V

IN

CEH

.

IN

℃

CIRCUIT

①

5/33

XC9235/XC9236/XC9237

Series

■ELECTRICAL CHARACTERISTICS (Continued)

XC9237A18Dxx, V

OUT

=1.8V, f

=3.0MHz, Ta=25℃

OSC

PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNIT

Output Voltage V

OUT

When connected to external components, V

IN=VCE

=5.0V, I

OUT

=30mA

1.764 1.800 1.836 V ①

Operating Voltage Range VIN 2.0 - 6.0 V ①

Maximum Output Current I

UVLO Voltage V

OUTMAX

UVLO

V When connected to external components

V Voltage which Lx pin holding “L” level

Supply Current IDD VIN=VCE=5.0V, V

Stand-by Current I

Oscillation Frequency f

PFM Switching Current I

PFM Duty Limit DTY

Maximum Duty Cycle DTY

Minimum Duty Cycle DTY

Efficiency EFFI

Lx SW "H" ON Resistance 1 R

Lx SW "H" ON Resistance 2 R

Lx SW "L" ON Resistance 1 R

Lx SW "L" ON Resistance 2 R

Lx SW "H" Leak Current

Lx SW "L" Leak Current

Current Limit

(*5)

I

(*5)

I

(*10)

I

Output Voltage

Temperature Characteristics

(V

CE "H" Voltage V

CE "L" Voltage V

VIN=5.0V, VCE=0V, V

STB

When connected to external components,

OSC

PFM

LIMIT_PFM

V

When connected to external components, V

VCE=VIN=(C-1), I

VIN=VCE=5.0V, V

MAX

VIN=VCE=5.0V, V

MIN

When connected to external components, V

VIN=VCE=5.0V, V

LxH

VIN=VCE=3.6V, V

LxH

VIN=VCE=5.0V

LxL

VIN=VCE=3.6V

LxL

VIN=V

LeakH

VIN=V

LeakL

VIN=VCE=5.0V, V

LIM

△V

/

・△Topr)

OUT

CEH

CEL

OUT

I

V Voltage changes Lx to “H” level V Voltage changes Lx to “L” level

When connected to external components,

PWM "H" Level Voltage V

PWMH

I becomes 2550kHz≦f

When connected to external components,

PWM "L" Level Voltage V

PWML

I

becomes f CE "H" Current I CE "L" Current I

Soft Start Time tSS

Latch Time t

Short Protection Threshold

Voltage

VIN=VCE=5.0V, V

CEH

VIN=5.0V, VCE=0V, V

CEL

When connected to external components,

V

LAT

Short Lx at 1Ω resistance

V

Sweeping V

V

SHORT

1Ω resistance, V “L” level within 1ms

IN=VOUT(E)

CE=VIN

IN=VOUT(E)

CE=VIN＝VOUT(E)

OUT

CE

IN=VCE

+2.0V, VCE=1.0V,

, V

=0V,

OUT

OUT=VOUT(E)

+2.0V, VCE=1.0V, I

+2.0V, VCE=VIN, I

OUT

OUT=VOUT(E)

+1.2V, I

OUT

(*4)

=5.0V, VCE=0V, Lx=0V - 0.01 1.0 μA ⑤

OUT

=5.0V, VCE=0V, Lx=5.0V - 0.01 1.0 μA ⑤

OUT

OUT=VOUT(E)

×1.1V - 21 35 μA ②

OUT=VOUT(E)

=1mA

×1.1V - 0 1.0 μA ②

=100mA

OUT

=1mA

OUT

(*12)

- 200 300 % ①

×0.9V 100 - - % ③ ×0.1V - - 0 % ③

=100mA

OUT

=0V, ILx=100mA

×0.9V

(*9)

(*1,*11)

(*12)

(*3)

- 0.35 0.55 Ω ④

(*3)

(*8)

900 1050 1350 mA ⑥

=30mA, -40℃≦Topr≦85℃ - ±100 -

=0V, Applied voltage to VCE,

(*6)

=1mA

=0V → VIN, I

, Voltage which oscillation frequency

OSC

(*6)

, Voltage which oscillation frequency

＜2550kHz

OSC

=0V - 0.1 - 0.1 μA ⑤

OUT

=0V - 0.1 - 0.1 μA ⑤

OUT

=1mA

=5.0V, V

OUT

=0.8×V

OUT

, VIN=VCE=5.0V, Short Lx at

OUT

voltage which Lx becomes

OUT

(*11)

≦3450kHz

(*13)

,

OUT(E)

(*7)

(*13)

600 - - mA ①

1.00 1.40 1.78 V ③

2550 3000 3450 kHz ①

170 220 270 mA ①

- 86 - % ①

- 0.42 0.67 Ω ④

- 0.45 0.65 Ω -

- 0.52 0.77 Ω -

ppm/

0.65 - 6.0 V ③

V

- 0.25 V ③

SS

- - V

V

–

IN

0.25

- 1.0 V ①

IN

- - V ①

0.5 0.9 2.5 ms ①

1.0 - 20 ms ⑦

0.675 0.900 1.150 V ⑦

Test conditions: Unless otherwise stated, VIN=5.0V, V NOTE:

*1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100 *3: ON resistance (Ω)= (V *4: R&D value *5: When temperature is high, a current of approximately 10μA (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,

control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than V mode when the CE/MODE pin voltage is equal to or lower than V

*7: Time until it short-circuits V *8: When V

*9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.

*10: Current limit denotes the level of detection at peak of coil current. *11: “H”=V *12: XC9235 series exclude I *13: XC9235/9236 series exclude V

is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.

IN

If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.

-1.2V, “L”=+0.1V~-0.1V

IN~VIN

- Lx pin measurement voltage) / 100mA

IN

with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.

OUT

and DTY

PFM

LIMIT_PFM

and V

=Nominal Voltage

OUT(E)

minus 1.0V and equal to or greater than V

IN

because those are only for the PFM control’s functions.

because those are only for the XC9237 series’ functions.

CEH

minus 0.3V, and to the PWM

.

IN

6/33

℃

CIRCUIT

①

XC9235/XC9236/XC9237

■ELECTRICAL CHARACTERISTICS (Continued)

XC9237B(C)(E)(G)18Cxx, V

PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNIT

Output Voltage V

Operating Voltage Range (B/C series) Operating Voltage Range (E/G series)

Maximum Output Current I

UVLO Voltage V

Supply Current IDD V

Stand-by Current I

Oscillation Frequency f

PFM Switching Current I

PFM Duty Limit

Maximum Duty Cycle

Minimum Duty Cycle

Efficiency

Lx SW "H" ON Resistance 1 R

Lx SW "H" ON Resistance 2 R

Lx SW "L" ON Resistance 1 R

Lx SW "L" ON Resistance 2 R

Lx SW "H" Leak Current

Current Limit

Output Voltage

Temperature Characteristics

CE "H" Voltage V

CE "L" Voltage V

PWM "H" Level Voltage V

PWM "L" Level Voltage V

CE "H" Current I

CE "L" Current I

Soft Start Time (B/G Series) tSS

Soft Start Time (C/E Series) tSS

Latch Time t

Short Protection Threshold

Voltage (B/C Series)

Short Protection Threshold

Voltage (E/G Series)

CL Discharge R

Test conditions: Unless otherwise stated, VIN=5.0V, V NOTE:

*1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100

*3: ON resistance (Ω)= (V *4: R&D value *5: When temperature is high, a current of approximately 10μA (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,

control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than V

mode when the CE/MODE pin voltage is equal to or lower than V *7: Time until it short-circuits V *8: When V *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.

If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.

*10: Current limit denotes the level of detection at peak of coil current.

*11: “H”=V

*12: XC9235 series exclude I

*13: XC9235/9236 series exclude V

*14: V

(*2)

EFFI

(*5)

(*10)

I

is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.

IN

-1.2V, “L”=+0.1V~-0.1V

IN~VIN

is applied when V

IN

=1.8V, f

OUT

VIN

OUTMAX

UVLO

STB

OSC

PFM

DTY

LIMIT_PFM

DTY

LxH

LxL

I

IN

OUT (E)

LeakH

LIM

△V

OUT

(V

・△Topr)

OUT

CEH

CEL

PWMH

PWML

CEH

CEL

LAT

V

SHORT

V

SHORT

DCHG

- Lx pin measurement voltage) / 100mA

with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.

OUT

and DTY

PFM

PWMH

x 0.5V becomes more than VIN.

=1.2MHz, Ta=25℃

OSC

When connected to external components, V

IN=VCE

=5.0V, I

=30mA

OUT

1.764 1.800 1.836 V ①

2.0 - 6.0

1.8 - 6.0 V

IN=VOUT(E)

When connected to external components V

CE

Voltage which Lx pin holding “L” level

IN=VCE

VIN=5.0V, VCE=0V, V

When connected to external components, V

IN=VOUT(E)

When connected to external components, V

IN=VOUT(E)

V

CE=VIN

V

MAX

MIN

IN=VCE

V

IN=VCE

When connected to external components, V

CE=VIN=VOUT(E)

VIN=VCE=5.0V, V

VIN=VCE=3.6V, V

VIN=VCE=5.0V

VIN=VCE=3.6V

VIN=V

V

IN=VCE

/

I

OUT

V

OUT

Voltage changes Lx to “H” level V

OUT

Voltage changes Lx to “L” level

When connected to external components, I

(*6)

, Voltage which oscillation frequency becomes 1020

kHz

When connected to external components, I

(*6)

, Voltage which oscillation frequency becomes f

1020kHz

VIN=VCE=5.0V, VIN=5.0V, VCE=0V,

When connected to external components, V

CE

When connected to external components, V

CE

VIN=VCE=5.0V, V Short Lx at 1 Sweeping V 1

Ω

level within 1ms

V

IN=VCE

decreasing V

VIN=5.0V, LX=5.0V, VCE=0V, V

OUT(E)

because those are only for the PFM control’s functions.

LIMIT_PFM

and V

because those are only for the XC9237 series’ functions.

PWML

+2.0V, VCE=1.0V,

=VIN, V

OUT=VOUT(E)

=5.0V, V

OUT=VOUT(E)

+2.0V, VCE =1.0V, I

+2.0V, VCE =VIN, I

=(C-1), I

=5.0V, V

=1mA

OUT

OUT=VOUT(E)

+1.2V, I

OUT (E)

(*4)

- 0.45 0.65 Ω ④

(*4)

=5.0V, VCE=0V, Lx=0V - 0.01 1.0 μA ⑤

OUT

=5.0V, V

OUT=VOUT(E)

(*14)

×0.5V

×1.1V - 15 33 μA ②

×1.1V - 0 1.0 μA ②

=100mA

OUT

=1mA

OUT

(*12)

200 300 % ①

×0.9V 100 - - % ③ ×1.1V - - 0 % ③

=100mA

OUT

×0.9V , ILx=100mA ×0.9V , ILx=100mA

×0.9V

(*9)

(*1, *11)

(*12)

(*3)

- 0.35 0.55 Ω ④

(*3)

- 0.42 0.67 Ω ④

(*8)

900 1050 1350 mA ⑥

600 - - mA ①

1.00 1.40 1.78 V ③

1020 1200 1380 kHz ①

120 160 200 mA ①

- 92 - % ①

- 0.52 0.77 Ω -

=30mA, -40℃≦Topr≦85℃ - ±100 -

=

V

×0.9V, Applied voltage to VCE,

OUT(E)

=

V

×0.9V, Applied voltage to VCE ,

OUT(E)

≦

f

≦

1380kHz

OSC

(*13)

=0V → VIN, I

resistance, V

=5.0V, The V

=Nominal Voltage, applied voltage sequence is V

(*13)

V

=

V

OUT

OUT(E)

V

=

OUT

=1mA

OUT

=1mA

OUT

=0.8×V

OUT

Ω

resistance

, VIN=VCE=5.0V, Short Lx at

OUT

voltage which Lx becomes “L”

OUT

from

V

OUT

minus 1.0V and equal to or greater than V

IN

(*11)

=1mA

OUT

=1mA

OUT

×0.9V - 0.1 - 0.1 μA ⑤

V

×0.9V - 0.1 - 0.1 μA ⑤

OUT(E)

,

OUT(E) (*7)

at Lx=”Low"

×0.4V

(E)

(*11)

while

=open 200 300 450 Ω ⑧

OUT

0.65 - 6.0 V ③

- 0.25 V ③

V

SS

- - V

–

V

IN

＜

OSC

0.25

- 0.25 0.40 ms ①

0.5 1.0 2.5 ms ①

1.0 - 20.0 ms ⑦

0.675 0.900 1.150 V ⑦

0.338 0.450 0.563 V ⑦

CEH

.

OUT→VIN→VCE

- - V ①

V ①

ppm/

- 1.0 V ①

IN

minus 0.3V, and to the PWM

IN

℃

Series

CIRCUIT

①

7/33

XC9235/XC9236/XC9237

■ELECTRICAL CHARACTERISTICS (Continued)

XC9237B(C)(E)(G)18Dxx, V

OUT

=1.8V, f

=3.0MHz, Ta=25℃

OSC

Series

PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNIT

Output Voltage V

Operating Voltage Range (B/C series)

Operating Voltage Range (E/G series)

Maximum Output Current I

UVLO Voltage V

OUT

VIN

OUTMAX

UVLO

Supply Current IDD V

Stand-by Current I

Oscillation Frequency f

PFM Switching Current I

PFM Duty Limit

Maximum Duty Cycle

Minimum Duty Cycle

DTY

STB

OSC

PFM

LIMIT_PFM

DTY

Efficiency EFFI

Lx SW "H" ON Resistance 1 R

Lx SW "H" ON Resistance 2 R

Lx SW "L" ON Resistance 1 R

Lx SW "L" ON Resistance 2 R

Lx SW "H" Leak Current

Current Limit

(*5)

I

(*10)

I

Output Voltage

Temperature Characteristics

CE "H" Voltage V

CE "L" Voltage V

PWM "H" Level Voltage V

PWM "L" Level Voltage V

CE "H" Current I CE "L" Current I

(V

LeakH

LIM

△V

・△Topr)

OUT

CEH

CEL

PWMH

PWML

CEH

CEL

LxH

LxL

OUT

Soft Start Time (B/G Series) tSS

Soft Start Time (C/E Series) tSS

Latch Time t

Short Protection Threshold

Voltage (B/C Series)

Short Protection Threshold

Voltage (E/G Series)

CL Discharge R

Test conditions: Unless otherwise stated, VIN=5.0V, V NOTE:

*1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100 *3: ON resistance (Ω)= (V *4: R&D value *5: When temperature is high, a current of approximately 10μA (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,

control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than V

mode when the CE/MODE pin voltage is equal to or lower than V *7: Time until it short-circuits V *8: When V *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.

*10: Current limit denotes the level of detection at peak of coil current.

*11: “H”=V *12: XC9235 series exclude I *13: XC9235/9236 series exclude V

*14: V

is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.

IN

If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance.

-1.2V, “L”=+0.1V~-0.1V

IN~VIN

is applied when V

IN

- Lx pin measurement voltage) / 100mA

IN

OUT (E)

LAT

V

SHORT

V

SHORT

DCHG

with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.

OUT

and DTY

PFM

PWMH

x 0.5V becomes more than VIN.

When connected to external components, V

IN=VCE

=5.0V, I

OUT

=30mA

2.0 - 6.0

1.8 - 6.0 V

IN=VOUT(E)

When connected to external components V

CE=VIN

Voltage which Lx pin holding “L” level

IN=VCE

VIN=5.0V, VCE=0V, V

When connected to external components, V

IN=VOUT(E)

When connected to external components, V

IN=VOUT(E)

V

CE=VIN

V

MAX

MIN

IN=VCE

V

IN=VCE

+2.0V, VCE=1.0V,

, V

OUT=VOUT(E)

=5.0V, V

×0.5V

OUT=VOUT(E)

+2.0V, VCE=1.0V, I

+2.0V, VCE=VIN, I

=(C-1), I

=5.0V, V

=1mA

OUT

OUT=VOUT(E)

(*9)

(*14)

,

(*1,*11)

×1.1V - 21 35 μA ②

×1.1V - 0 1.0 μA ②

=100mA

OUT

(*12)

=1mA

OUT

(*12)

- 200 300 % ①

×0.9V 100 - - % ③ ×0.1V - - 0 % ③

When connected to external components, V

CE=VIN＝VOUT(E)

VIN=VCE=5.0V, V

VIN=VCE=3.6V, V

VIN=VCE=5.0V

VIN=VCE=3.6V

VIN=V

OUT

VIN=VCE=5.0V, V

/

I

=30mA, -40℃≦Topr≦85℃ - ±100 -

OUT

V

=

V

OUT

OUT(E)

Voltage changes Lx to “H” level V

=

V

OUT

OUT(E)

Voltage changes Lx to “L” level

When connected to external components, I

=1mA

OUT

becomes 2550kHz≦f

When connected to external components, I

=1mA

OUT

becomes f

VIN=VCE=5.0V, VIN=5.0V, VCE=0V,

+1.2V, I

OUT

(*4)

=5.0V, VCE=0V, Lx=0V - 0.01 1.0 μA ⑤

OUT=VOUT(E)

×0.9V, Applied voltage to VCE,

(*6)

, Voltage which oscillation frequency

(*6)

, Voltage which oscillation frequency

＜2550kHz

OSC

V

OUT

=100mA

OUT

=

V

×0.9V, ILx=100mA

OUT(E)

=

V

×0.9V, ILx=100mA

OUT(E)

(*8)

×0.9V

≦3450kHz

OSC

(*13)

=

V

×0.9V - 0.1 - 0.1 μA ⑤

OUT(E)

V

=

V

OUT

OUT(E)

900 1050 1350 mA ⑥

(*11)

(*13)

×0.9V - 0.1 - 0.1 μA ⑤

When connected to external components, V

=0V → VIN, I

CE

OUT

=1mA

When connected to external components, V

=0V → VIN, I

CE

VIN=VCE=5.0V, V Short Lx at 1

Sweeping V 1

Ω

resistance, V

level within 1ms

V

=5.0V, The V

IN=VCE

decreasing V

VIN=5.0V, LX=5.0V, VCE=0V, V

=Nominal Voltage, applied voltage sequence is V

OUT(E)

because those are only for the PFM control’s functions.

LIMIT_PFM

and V

because those are only for the XC9237 series’ functions.

PWML

=1mA

OUT

=0.8×V

OUT

Ω

resistance

, VIN=VCE=5.0V, Short Lx at

OUT

voltage which Lx becomes “L”

OUT

from

V

OUT

minus 1.0V and equal to or greater than V

IN

OUT(E)

(*7)

at Lx=”Low"

×0.4V

OUT

(E)

,

(*11)

=open 200 300 450 Ω ⑧

OUT

while

1.764 1.800 1.836 V ①

V ①

600 - - mA ①

1.00 1.40 1.78 V ③

2550 3000 3450 kHz ①

170 220 270 mA ①

- 86 - % ①

(*3)

- 0.35 0.55 Ω ④

(*3)

- 0.42 0.67 Ω ④

- 0.45 0.65 Ω -

- 0.52 0.77 Ω -

ppm/

℃

0.65 - 6.0 V ③

- 0.25 V ③

V

SS

- - V

–

V

IN

0.25

- 1.0 V ①

IN

- - V ①

- 0.32 0.50 ms ①

0.5 0.9 2.5 ms ①

1.0 - 20 ms ⑦

0.675 0.900 1.150 V ⑦

0.338 0.450 0.563 V ⑦

CEH

minus 0.3V, and to the PWM

.

IN

OUT→VIN→VCE

CIRCUIT

①

8/33

■ELECTRICAL CHARACTERISTICS (Continued)

●XC9237D(F)08Cxx, FB Type, f

=1.2MHz, Ta=25℃

OSC

XC9235/XC9236/XC9237

Series

PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNIT

FB Voltage VFB

= VCE =5.0V, The VFB at Lx=”High"

V

IN

decreasing FB pin voltage from 0.9V.

(*11)

while

0.784 0.800 0.816 V ③

Operating Voltage Range VIN 1.8 - 6.0 V ①

=3.2V, VCE=1.0V

V

Maximum Output Current I

UVLO Voltage V

OUTMAX

UVLO

Supply Current IDD V

Stand-by Current I

Oscillation Frequency f

PFM Switching Current I

PFM Duty Limit

Maximum Duty Cycle

Minimum Duty Cycle

Efficiency

(*2)

EFFI

Lx SW "H" ON Resistance 1 R Lx SW "H" ON Resistance 2 R Lx SW "L" ON Resistance 1 R Lx SW "L" ON Resistance 2 R Lx SW "H" Leak Current

Current Limit

(*5)

ILeakH VIN = VFB = 5.0V, VCE = 0V, LX= 0V - 0.01 1.0 μA ⑨

(*10)

I

Output Voltage

Temperature Characteristics

CE "H" Voltage V

CE "L" Voltage V

PWM "H" Level Voltage V

PWM "L" Level Voltage V

CE "H" Current I

CE "L" Current I Soft Start Time (D series) 0.5 1.0 2.5 Soft Start Time (F series)

Latch Time t

Short Protection Threshold

Voltage

V

STB

OSC

PFM

DTY

LIMIT_PFM

DTY

MAX

DTY

MIN

LｘH

LｘL

V

LIM

△

V

OUT

(V

・△

OUT

CEH

CEL

PWMH

PWML

V

CEH

V

CEL

t

SS

LAT

V

SHORT

V

V V V

/

Topr)

IN

When connected to external components

=

VIN ,

V Voltage which Lx pin holding “L” level

VFB = 0.4V,

CE

=VCE=5.0V, VFB= 0.88V - 15 μA ②

IN

=5.0V, VCE=0V, VFB= 0.88V - 0 1.0 μA ②

IN

When connected to external components, V

= 3.2V, VCE=1.0V, I

IN

=100mA

OUT

When connected to external components, V

=3.2V, VCE = VIN , I

IN

= VIN =2.0V I

V

CE

V

= VCE =5.0V, VFB = 0.72V 100 - - % ③

IN

V

= VCE =5.0V, VFB = 0.88V - - 0 % ③

IN

OUT

=1mA

(*12)

200 300 % ①

When connected to external components, V

= VIN ＝ 2.4V, I

CE

= VCE = 5.0V, VFB = 0.72V,ILX = 100mA

IN

= VCE = 3.6V, VFB = 0.72V,ILX = 100mA

IN

= VCE = 5.0V

IN

= VCE = 3.6V

IN

= VCE= 5.0V, VFB = 0.72V

IN

I

=30mA

OUT

-40℃≦Topr≦85℃

=0.72V, Applied voltage to VCE,

V

FB

Voltage changes Lx to “H” level

=0.72V, Applied voltage to VCE,

V

FB

Voltage changes Lx to “L” level When connected to external components, I

OUT

frequency becomes 1020kHz≦f

(*13)

When connected to external components, I

OUT

frequency becomes f

(*6)

=1mA

, Voltage which oscillation

(*6)

=1mA

= VCE =5.0V, VFB =0.72V - 0.1 - 0.1 μA ⑤

IN

=5.0V, VCE = 0V, VFB =0.72V - 0.1 - 0.1 μA ⑤

IN

, Voltage which oscillation

= 100mA

OUT

(*4)

- 0.45 0.65 Ω -

(*4)

- 0.52 0.77 Ω -

＜1020kHz

OSC

When connected to external components, V

= 0V → VIN , I

CE

=

VCE=5.0V,

V

IN

resistance

= VCE =5.0V, The VFB at Lx=”Low"

V

IN

decreasing FB pin voltage from 0.4V.

VFB=0.64,

(*7)

=1mA

OUT

Short Lx at 1Ω

600 - - mA ①

1.00 1.40 1.78 V ③

(*1,*11)

(*9)

1020 1200 1380 kHz ①

(*12)

120 160 200 mA ①

- 92 - % ①

(*3)

- 0.35 0.55 Ω ④

(*3)

- 0.42 0.67 Ω ④

(*8)

900 1050 1350 mA ⑥

- ±100 - ppm/ ℃ ①

(*11)

≦1380kHz

OSC

(*13)

0.65 - 6.0 V ③

V

SS

- - V

V

IN

0.25

- 0.25 0.40

- 0.25 V ③

- 1.0 V ①

IN

-

- - V ①

ms ①

1.0 - 20.0 ms ⑦

(*11)

while

0.15 0.200 0.25 V ⑦

CIRCUIT

CL Discharge R

Test conditions: V V

OUT→VIN→VCE

NOTE:

*1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100 *3: ON resistance (Ω)= (V *4: R&D value

*5: When temperature is high, a current of approximately 10μA (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,

control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than V

mode when the CE/MODE pin voltage is equal to or lower than V *7: Time until it short-circuits V *8: When V *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.

If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *10: Current limit denotes the level of detection at peak of coil current. *11: “H”=V *12: XC9235 series exclude I

*13: XC9235/9236 series exclude V

=1.2V when the external components are connected. Unless otherwise stated, VIN=5.0V, V

OUT

- Lx pin measurement voltage) / 100mA

IN

is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.

IN

-1.2V, “L”=+0.1V~-0.1V

IN~VIN

FB

PFM

VIN = 5.0V ,LX = 5.0V, VCE = 0V, VFB= open 200 300 450 Ω ⑧

DCHG

=Nominal Voltage, applied voltage sequence is

OUT(E)

minus 0.3V, and to the PWM

minus 1.0V and equal to or greater than V

with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.

and DTY

PWMH

because those are only for the PFM control’s functions.

LIMIT_PFM

and V

because those are only for the XC9237 series’ functions.

PWML

IN

CEH

.

IN

9/33

XC9235/XC9236/XC9237

Series

■ELECTRICAL CHARACTERISTICS (Continued)

●XC9237D(F)08Dxx, FB, f

PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNIT

FB Voltage

Operating Voltage Range

Maximum Output Current

UVLO Voltage

Supply Current

Stand-by Current

Oscillation Frequency

PFM Switching Current

PFM Duty Limit

Maximum Duty Cycle

Minimum Duty Cycle

Voltage

(*2)

(*10)

Efficiency

Lx SW "H" ON Resistance 1 Lx SW "H" ON Resistance 2 Lx SW "L" ON Resistance 1 Lx SW "L" ON Resistance 2 Lx SW "H" Leak Current

Current Limit

Output Voltage

Temperature Characteristics

CE "H" Voltage

CE "L" Voltage

PWM "H" Level Voltage

PWM "L" Level Voltage

CE "H" Current

CE "L" Current Soft Start Time (D series) Soft Start Time (F series)

Latch Time

Short Protection Threshold

=3.0MHz, Ta=25℃

OSC

V

FB

V

IN

I

OUTMAX

V

UVLO

I

DD

I

STB

f

OSC

I

PFM

DTY

LIMIT_PFM

DTY

EFFI

R

LｘH

R

LｘH

R

LｘL

R

(*5)

LｘL

ILeakH V

I

LIM

△

V

OUT

(V

・△

OUT

V

CEH

V

CEL

V

PWMH

V

PWML

I

CEH

I

CEL

t

SS

t

LAT

V

SHORT

V

= VCE =5.0V, The VFB at Lx=”High"

IN

decreasing FB pin voltage from 0.9V.

(*11)

while

1.8 - 6.0 V ①

V

=3.2V, VCE=1.0V

IN

When connected to external components

V

=

VIN ,

VFB = 0.4V ,

V

MAX

MIN

CE

Voltage which Lx pin holding “L” level

=VCE=5.0V, VFB= 0.88V - 21 35 μA ②

IN

=5.0V, VCE=0V, VFB= 0.88V - 0 1.0 μA ②

IN

When connected to external components,

= 3.2V, VCE=1.0V, I

V

IN

When connected to external components,

=3.2V, VCE = VIN , I

V

IN

VCE= VIN =2.2V I

OUT

=1mA

=100mA

(*12)

=1mA

(*12)

200 300 % ①

VIN = VCE =5.0V, VFB = 0.72V 100 - - % ③

VIN = VCE =5.0V, VFB = 0.88V - - 0 % ③

(*9)

(*1, *11)

When connected to external components, V

= VIN ＝ 2.4V, I V V

V V

V

/

Topr)

CE

= VCE = 5.0V, VFB = 0.72V,ILX = 100mA

IN

= VCE = 3.6V, VFB = 0.72V,ILX = 100mA

IN

= VCE = 5.0V

IN

= VCE = 3.6V

IN

= VFB = 5.0V, VCE = 0V, LX= 0V - 0.01 1.0 μA ⑨

IN

= VCE= 5.0V, VFB = 0.72V

IN

I

=30mA

OUT

-40℃≦Topr≦85℃ V

=0.72V , V

FB

Voltage changes Lx to “H” level V

=0.72V, VCE,

FB

Voltage changes Lx to “L” level When connected to external components, I

= 1mA

OUT

becomes

When connected to external components, I

= 1mA

OUT

becomes V V

= VCE =5.0V, VFB =0.72V - 0.1 - 0.1 μA ⑤

IN

=5.0V, VCE = 0V, VFB =0.72V - 0.1 - 0.1 μA ⑤

IN

When connected to external components, V

= 0V → VIN , I

CE

V

= VCE

IN

Short Lx at 1

V

= VCE =5.0V, The VFB at Lx=”Low"

IN

decreasing FB pin voltage from 0.4V.

(*6)

, Voltage which oscillation frequency

2550kHz≦f

(*6)

, Voltage which oscillation frequency

f

＜2550kHz

OSC

= 5.0V,

Ω

resistance

= 100mA

OUT

(*4)

- 0.45 0.65 Ω -

(*4)

- 0.52 0.77 Ω -

(*8)

900 1050 1350 mA ⑥

CE,

OSC

=1mA

OUT

VFB = 0.64,

(*11)

≦3450kHz

(*13)

(*7)

(*13)

(*11)

(*3)

while

CIRCUIT

0.784 0.800 0.816 V ③

600 - - mA ①

1.00 1.40 1.78 V ③

2550 3000 3450 kHz ①

170 220 270 mA ①

- 86 - % ①

- 0.35 0.55 Ω ④

- 0.42 0.67 Ω ④

- ±100 - ppm/ ℃ ①

0.65 - 6.0 V ③

V

SS

- - V

V

IN

0.25

0.5 1.0 2.5

- 0.25 0.40

- 0.25 V ③

- 1.0 V ①

IN

-

- - V ①

ms ①

1.0 - 20.0 ms ⑦

0.15 0.200 0.25 V ⑦

CL Discharge

Test conditions: V V

OUT→VIN→VCE

NOTE:

*1: Including hysteresis operating voltage range. *2: EFFI = { ( output voltage×output current ) / ( input voltage×input current) }×100

*3: ON resistance (Ω)= (V *4: R&D value *5: When temperature is high, a current of approximately 10μA (maximum) may leak. *6: The CE/MODE pin of the XC9237A series works also as an external switching pin of PWM control and PWM/PFM control. When the IC is in the operation,

control is switched to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or greater than V

mode when the CE/MODE pin voltage is equal to or lower than V *7: Time until it short-circuits V *8: When V *9: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.

If current is further pulled from this state, output voltage will decrease because of P-ch driver ON resistance. *10: Current limit denotes the level of detection at peak of coil current. *11: “H”=V *12: XC9235 series exclude I *13: XC9235/9236 series exclude V

=1.2V when the external components are connected. Unless otherwise stated, VIN=5.0V, V

OUT

- Lx pin measurement voltage) / 100mA

IN

is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.

IN

-1.2V, “L”=+0.1V~-0.1V

IN~VIN

FB

PFM

VIN = 5.0V ,LX = 5.0V ,VCE = 0V ,VFB= open 200 300 450 Ω ⑧

R

DCHG

=Nominal Voltage, applied voltage sequence is

OUT(E)

minus 0.3V, and to the PWM

minus 1.0V and equal to or greater than V

with GND via 1Ωof resistor from an operational state and is set to Lx=0V from current limit pulse generating.

and DTY

PWMH

because those are only for the PFM control’s functions.

LIMIT_PFM

and V

because those are only for the XC9237 series’ functions.

PWML

IN

CEH

.

IN

10/33

XC9235/XC9236/XC9237

■ELECTRICAL CHARACTERISTICS (Continued)

●PFM Switching Current (I

SETTING VOLTAGE

1.2V＜V

●Input Voltage (V

Minimum operating voltage is 2.0V.

ex.) Although when V

●Soft-Start Time, Setting Voltage（XC9235B(G)/9236B(G)/9237B(G) Series only）

(μs)

(mA)

V

≦1.2V

OUT(E)

≦1.75V

OUT(E)

1.8V≦V

f

OSC

OUT(E)

) for Measuring PFM Duty Limit (DTY

IN

1.2MHz 3.0MHz

C-1 V

is 1.2V and f

OUT(E)

SERIES f

XC9235B(G)/XC9237B(G)

XC9236B(G)

XC9235B(G)/

XC9236B(G)/XC9237B(G)

) by Oscillation Frequency and Setting Voltage

PFM

1.2MHz 3.0MHz

MIN. TYP. MAX. MIN. TYP. MAX.

140 180 240 190 260 350 130 170 220 180 240 300 120 160 200 170 220 270

LIMIT_PFM

+0.5V V

OUT(E)

is 1.2MHz, (C-1) should be 1.7V, (C-1) becomes 2.0V for the minimum operating voltage 2.0V.

OSC

SETTING VOLTAGE

OSC

1.2MHz

3.0MHz

0.8≦V

1.5≦V

1.8≦V

2.5≦V

0.8≦V

2.5≦V

0.8≦V

1.8≦V

OUT(E)

<1.5

<1.8

<2.5

<4.0

<2.5

<4.0

<1.8

<4.0

)

+1.0V

OUT(E)

MIN. TYP. MAX.

- 250 400

- 320 500

- 250 400

- 320 500

- 250 400

- 320 500

- 250 400

- 320 500

Series

11/33

XC9235/XC9236/XC9237

■TYPICAL APPLICATION CIRCUIT

●XC9235/XC9236/XC9237A, B, C, E, G Series (Output Voltage Fixed)

V

OUT

600mA

C

L

(ceramic)

L

Lx

VSS

VOUT

●XC9235/XC9236/XC9237D, F Series (Output Voltage External Setting)

<Setting for Output Voltage> Output voltage can be set externally by adding two resistors to the FB pin. The output voltage is calculated by the R R

value. The total of R

FB2

Output voltages can be set in the range of 0.9V to 0.6V by use of 0.8V ± 2.0% reference voltage. However, when input voltage (V

) is lower than the setting output voltage, output voltage (V

IN

V

OUT

=0.8 × (R

The value of the phase compensation speed-up capacitor C

f

<10kHz. For optimization, f

ZFB

and R

FB1

FB1+RFB2

is usually selected less than 1MΩ.

FB2

)/R

FB2

can be adjusted in the range of 1kHz to 20kHz depending on the inductance L and

ZFB

V

VSS

CE/ MODE

IN

Series

(cera mic)

●f

IN

V

C

IN

CE/ MO DE

OUT

is calculated by the formula of f

FB

=3.0MHz

OSC

L:

CIN:

CL:

●f

=1.2MHz

OSC

L:

CIN:

CL:

) can not be higher than the input voltage (VIN).

1.5μH

4.7μF 10μF

4.7μH

4.7μF 10μF

(NR3015, TAIYO YUDEN) (Ceramic) (Ceramic)

(NR4018, TAIYO YUDEN) (Ceramic) (Ceramic)

= 1/(2×π×CFB×R

ZFB

the load capacitance CL which are used.

【Formula】 When R

=470kΩ and R

FB1

=150k, V

FB2

=0.8 × (470k+150k) / 150k=3.3V

OUT1

【Example】

V

RFB1 RFB2 CFB V

OUT

(V)

(kΩ) (kΩ)

(pF) (V)

RFB1 RFB2 CFB

OUT

(kΩ) (kΩ)

(pF)

0.9 100 820 150 2.5 510 240 100

1.2 150 300 100 3.0 330 120 150

1.5 130 150 220 3.3 470 150 100

1.8 300 240 150 4.0 120 30 470

FB1

and

) with

12/33

XC9235/XC9236/XC9237

Series

■OPERATIONAL DESCRIPTION

The XC9235/XC9236/XC9237 series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM comparator, phase compensation circuit, output voltage adjustment resistors, P-channel MOS driver transistor, N-channel MOS switching transistor for the synchronous switch, current limiter circuit, UVLO circuit and others. (See the block diagram above.) The series ICs compare, using the error amplifier, the voltage of the internal voltage reference source with the feedback voltage from the V amplifier output, to input a signal to the PWM comparator to determine the turn-on time during PWM operation. The PWM comparator compares, in terms of voltage level, the signal from the error amplifier with the ramp wave from the ramp wave circuit, and delivers the resulting output to the buffer driver circuit to cause the Lx pin to output a switching duty cycle. This process is continuously performed to ensure stable output voltage. The current feedback circuit monitors the P-channel MOS driver transistor current for each switching operation, and modulates the error amplifier output signal to provide multiple feedback signals. This enables a stable feedback loop even when a low ESR capacitor such as a ceramic capacitor is used ensuring stable output voltage.

<Reference Voltage Source> The reference voltage source provides the reference voltage to ensure stable output voltage of the DC/DC converter.

<Ramp Wave Circuit> The ramp wave circuit determines switching frequency. The frequency is fixed internally and can be selected from 1.2MHz or

3.0MHz. Clock pulses generated in this circuit are used to produce ramp waveforms needed for PWM operation, and to synchronize all the internal circuits.

<Error Amplifier> The error amplifier is designed to monitor output voltage. The amplifier compares the reference voltage with the feedback voltage divided by the internal split resistors, R1 and R2. When a voltage lower than the reference voltage is fed back, the output voltage of the error amplifier increases. The gain and frequency characteristics of the error amplifier output are fixed internally to deliver an optimized signal to the mixer.

<Current Limit> The current limiter circuit of the XC9235/XC9236/XC9237 series monitors the current flowing through the P-channel MOS driver transistor connected to the Lx pin, and features a combination of the current limit mode and the operation suspension mode. ① When the driver current is greater than a specific level, the current limit function operates to turn off the pulses from the Lx

pin at any given timing.

② When the driver transistor is turned off, the limiter circuit is then released from the current limit detection state. ③ At the next pulse, the driver transistor is turned on. However, the transistor is immediately turned off in the case of an over

current state.

④ When the over current state is eliminated, the IC resumes its normal operation.

The IC waits for the over current state to end by repeating the steps ① through ③. If an over current state continues for a few ms and the above three steps are repeatedly performed, the IC performs the function of latching the OFF state of the driver transistor, and goes into operation suspension mode. Once the IC is in suspension mode, operations can be resumed by either turning the IC off via the CE/MODE pin, or by restoring power to the V not mean a complete shutdown, but a state in which pulse output is suspended; therefore, the internal circuitry remains in operation. The current limit of the XC9235/XC9236/XC9237 series can be set at 1050mA at typical. Besides, care must be taken when laying out the PC Board, in order to prevent misoperation of the current limit mode. Depending on the state of the PC Board, latch time may become longer and latch operation may not work. In order to avoid the effect of noise, the board should be laid out so that input capacitors are placed as close to the IC as possible.

OUT pin through split resistors, R1 and R2. Phase compensation is performed on the resulting error

pin. The suspension mode does

IN

Limit<#ms

Limit>#ms

ILx

V

VCE

OUT

Lx

Restart

VIN

13/33

I

LIM

0mA

VSS

XC9235/XC9236/XC9237

■OPERATIONAL DESCRIPTION (Continued)

<Short-Circuit Protection> The short-circuit protection circuit monitors the internal R1 and R2 divider voltage from the V the block diagram shown in the previous page). In case where output is accidentally shorted to the Ground and when the FB point voltage decreases less than half of the reference voltage (Vref) and a current more than the I the Pch MOS driver transistor, the short-circuit protection quickly operates to turn off and to latch the driver transistor. For the D/E/F/G series, it does not matter how much the current limit, once the FB voltage become less than the quarter of reference voltage (V latch mode, the operation can be resumed by either turning the IC off and on via the CE/MODE pin, or by restoring power supply to the VIN pin. When sharp load transient happens, a voltage drop at the V short circuit protection may operate in the voltage higher than 1/2 V

<UVLO Circuit> When the V prevent false pulse output caused by unstable operation of the internal circuitry. When the V or higher, switching operation takes place. By releasing the UVLO function, the IC performs the soft start function to initiate output startup operation. The soft start function operates even when the VIN pin voltage falls momentarily below the UVLO operating voltage. The UVLO circuit does not cause a complete shutdown of the IC, but causes pulse output to be suspended; therefore, the internal circuitry remains in operation.

<PFM Switch Current> In PFM control operation, until coil current reaches to a specified level (I on. In this case, time that the Pch MOS driver transistor is kept on (TON) can be given by the following formula.

TON= L×IPFM / (VIN－VOUT) →IPFM①

< PFM Duty Limit > In PFM control operation, the PFM duty limit ( duty increases (e.g. the condition that the step-down ratio is small), it’s possible for Pch MOS driver transistor to be turned off even when coil current doesn’t reach to IPFM. →IPFM②

IN pin voltage becomes 1.4V or lower, the Pch MOS driver transistor output driver transistor is forced OFF to

), the short-circuit protection operates to latch the Pch MOS driver transistor. In

REF

Series

DTY

LIMIT_PFM

pin (refer to FB point in

OUT

flows to

LIM

is propagated to the FB point through CFB, as a result,

OUT

) is set to 200% (TYP.). Therefore, under the condition that the

voltage.

OUT

pin voltage becomes 1.8V

IN

PFM), the IC keeps the Pch MOS driver transistor

14/33

XC9235/XC9236/XC9237

■OPERATIONAL DESCRIPTION (Continued)

＜CL High Speed Discharge＞

XC9235B(C)(D)(E)(F)(G)/ XC9236B(C)(D)(E)(F)(G)/ XC9237B(C)(D)(E)(F)(G) series can quickly discharge the electric charge at the output capacitor (C inputted via the Nch MOS switch transistor located between the LX pin and the VSS pin. When the IC is disabled, electric charge at the output capacitor (C output capacitor (C of a CL auto-discharge resistance value [R] and an output capacitor value (CL) as τ(τ=C x R), discharge time of the output voltage after discharge via the N channel transistor is calculated by the following formulas.

V = V

x e

OUT(E)

V : Output voltage after discharge V

: Output voltage

OUT(E)

t: Discharge time, τ: C x R

C= Capacitance of Output capacitor (CL) R= C

) is set by the CL auto-discharge resistance (R) and the output capacitor (CL). By setting time constant

L

–t/

τ

or t=τln (V

auto-discharge resistance

L

) when a low signal to the CE pin which enables a whole IC circuit put into OFF state, is

L

) is quickly discharged so that it may avoid application malfunction. Discharge time of the

L

/ V)

OUT(E)

Series

Output Voltage Dischage Characteristics

Rdischg

100

90

80

70

60

50

40

30

20

10

0

0 102030405060708090100

= 300Ω TYP

（）

CL=10uF

CL=20uF

CL=50uF

Discharge Time t (ms)

15/33

p

XC9235/XC9236/XC9237

Series

■OPERATIONAL DESCRIPTION (Continued)

<CE/MODE Pin Function> The operation of the XC9235/XC9236/XC9237 series will enter into the shut down mode when a low level signal is input to the CE/MODE pin. During the shutdown mode, the current consumption of the IC becomes 0μA (TYP.), with a state of high impedance at the Lx pin and V input to the CE/MODE pin is a CMOS input and the sink current is 0μA (TYP.).

●XC9235/XC9236 series - Examples of how to use CE/MODE pin

(A)

SW＿CE

ON Stand-by

OFF Operation

(B)

SW＿CE

ON Operation

OFF Stand-by

●XC9237 series - Exam

(A)

SW＿CE SW＿PWM/PFM

ON * PWM/PFM Automatic Switching Control

OFF ON PWM Control

OFF OFF Stand-by

(B)

SW＿CE SW＿PWM/PFM

ON * Stand-by

OFF ON PWM Control

OFF OFF PWM/PFM Automatic Switching Control

Intermediate voltage can be generated by RM1 and RM2. Please set the value of each R1, R2, RM1, RM2 from few hundreds kΩ to few hundreds MΩ. For switches, CPU open-drain I/O port and transistor can be used.

STATUS

OUT pin. The IC starts its operation by inputting a high level signal to the CE/MODE pin. The

(A)

(B)

les of how to use CE/MODE pin

STATUS

(A)

(B)

16/33

XC9235/XC9236/XC9237

Series

■OPERATIONAL DESCRIPTION (Continued)

＜Soft Start＞

Soft start time is available in two options via product selection. The A,C,D,and E types of XC9235/XC9236/XC9237 series provide 1.0ms (TYP).

The B,F, and G types of XC9235/ XC9236/XC9237 series provide 0.25ms (TYP). However, for the D/F the soft-start time can be set by the external components. Soft start time is defined as the time interval to reach 90% of the output voltage from the time when the CE pin is turned on.

0V

V

CEH

V

OUT

0V

■FUNCTION CHART

VOLTAGE LEVEL

L Level

(*1)

(*2)

(*3)

Stand-by Stand-by Stand-by

VCE/

– 0.25V < VCE/

IN

VCE/

MODE

H Level

M Level

Note on CE/MODE pin voltage level range (*1) H level: 0.65V <

H level: V (*2) M level: 0.65V < VCE/ (*3) L level: 0V <

XC9235 XC9236 XC9237

Synchronous

PWM Fixed Control

━ ━

< 6.0V (for XC9235/XC9236)

MODE

< VIN - 1.0V (for XC9237)

MODE

< 0.25V

< V

IN

(for XC9237)

t

SS

OPERATIONAL STATES CE/MODE

Synchronous

PWM/PFM

Automatic Switching

Synchronous

PWM/PFM

Automatic Switching

Synchronous

PWM Fixed Control

90% of setting voltage

17/33

XC9235/XC9236/XC9237

■NOTE ON USE

1. The XC9235/XC9236/XC9237 series is designed for use with ceramic output capacitors. If, however, the potential difference is too large between the input voltage and the output voltage, a ceramic capacitor may fail to absorb the resulting high switching energy and oscillation could occur on the output. If the input-output potential difference is large, connect an electrolytic capacitor in parallel to compensate for insufficient capacitance.

2. Spike noise and ripple voltage arise in a switching regulator as with a DC/DC converter. These are greatly influenced by external component selection, such as the coil inductance, capacitance values, and board layout of external components. Once the design has been completed, verification with actual components should be done.

3. Depending on the input-output voltage differential, or load current, some pulses may be skipped, and the ripple voltage may increase.

4. When the difference between V possibility that some cycles may be skipped completely.

5. When the difference between V there is the possibility that some cycles may be skipped completely.

6. With the IC, the peak current of the coil is controlled by the current limit circuit. Since the peak current increases when dropout voltage or load current is high, current limit starts operation, and this can lead to instability. When peak current becomes high, please adjust the coil inductance value and fully check the circuit operation. In addition, please calculate the peak current according to the following formula:

Ipk = (V L: Coil Inductance Value f

7. When the peak current which exceeds limit current flows within the specified time, the built-in Pch MOS driver transistor turns off. During the time until it detects limit current and before the built-in transistor can be turned off, the current for limit current flows; therefore, care must be taken when selecting the rating for the external components such as a coil.

8. When V

9. Care must be taken when laying out the PC Board, in order to prevent misoperation of the current limit mode. Depending on the state of the PC Board, latch time may become longer and latch operation may not work. In order to avoid the effect of noise, the board should be laid out so that input capacitors are placed as close to the IC as possible.

10. Use of the IC at voltages below the recommended voltage range may lead to instability.

11. This IC should be used within the stated absolute maximum ratings in order to prevent damage to the device.

12. When the IC is used in high temperature, output voltage may increase up to input voltage level at no load because of the

leak current of the driver transistor.

13. The current limit is set to 1350mA (MAX.)

①Current flows into Pch MOS driver transistor to reach the current limit (I

②The current of ILIM or more flows since the delay time of the circuit occurs during from the detection of the current limit to

③Because of no potential difference at both ends of the coil, the time rate of coil current becomes quite small. ④Lx oscillates very narrow pulses by the current limit for several ms. ⑤The circuit is latched, stopping its operation.

IN - VOUT) x OnDuty / (2 x L x f

: Oscillation Frequency

OSC

IN is less than 2.4V, limit current may not be reached because voltage falls caused by ON resistance.

current limit functions while the VOUT pin is shorted to the GND pin, when Pch MOS driver transistor is ON, the potential difference for input voltage will occur at both ends of a coil. For this, the time rate of coil current becomes large. By contrast, when Nch MOS driver transistor is ON, there is almost no potential difference at both ends of the coil since the

OUT pin is shorted to the GND pin. Consequently, the time rate of coil current becomes quite small. According to the

V repetition of this operation, and the delay time of the circuit, coil current will be converged on a certain current value, exceeding the amount of current, which is supposed to be limited originally. Even in this case, however, after the over current state continues for several ms, the circuit will be latched. A coil should be used within the stated absolute maximum rating in order to prevent damage to the device.

OFF of Pch MOS driver transistor.

IN and VOUT is large in PWM control, very narrow pulses will be outputted, and there is the

IN and VOUT is small, and the load current is heavy, very wide pulses will be outputted and

OSC

Series

) + IOUT

at typical. However, the current of 1350mA or more may flow. In case that the

LIM).

18/33

XC9235/XC9236/XC9237

Series

■NOTE ON USE (Continued)

14. In order to stabilize VIN’s voltage level and oscillation frequency, we recommend that a by-pass capacitor (CIN) be connected as close as possible to the V

15. High step-down ratio and very light load may lead an intermittent oscillation.

16. During PWM / PFM automatic switching mode, operating may become unstable at transition to continuous mode. Please verify with actual parts.

IN & VSS pins.

17. Please note the inductance value of the coil. The IC may enter unstable operation if the combination of ambient temperature, setting voltage, oscillation frequency, and L value are not adequate.

In the operation range close to the maximum duty cycle, The IC may happen to enter unstable output voltage operation

even if using the L values listed below.

18. It may happen to enter unstable operation when the IC goes into continuous operation mode under the condition of large input-output voltage difference. Care must be taken with the actual design unit.

●The Range of L Value

f

V

OSC

3.0MHz

1.2MHz

*When a coil less value of 4.7μH is used at

f

=1.2MHz or when a coil less value of 1.5μH is

OSC

used at f

reach the current limit ILMI. In this case, it may

happen that the IC can not provide 600mA output

current.

0.8V＜V

=3.0MHz, peak coil current more easily

OSC

L Value

OUT

<4.0V 1.0μH～2.2μH

OUT

V

≦2.5V 3.3μH～6.8μH

OUT

2.5V＜V

4.7μH～6.8μH

OUT

19/33

XC9235/XC9236/XC9237

Series

■NOTE ON USE (Continued)

●Instructions of pattern layouts

1. In order to stabilize VIN voltage level, we recommend that a by-pass capacitor (CIN) be connected as close as possible to the VIN & VSS pins.

2. Please mount each external component as close to the IC as possible.

3. Wire external components as close to the IC as possible and use thick, short connecting traces to reduce the circuit impedance.

4. Make sure that the PCB GND traces are as thick as possible, as variations in ground potential caused by high ground currents at the time of switching may result in instability of the IC.

5. This series’ internal driver transistors bring on heat because of the output current and ON resistance of driver transistors.

XC9235/9236/9237A, B, C (Output Voltage Fixed) XC9235/9236/9237A, B, C, E, G (Output Voltage Fixed)

CL

For the VIN, VOUT, VSS, CE, please put the wire.

Inductor

For the VIN, VOUT, VSS, CE, please put the wire.

XC9235/9236/9237D, F (Output Voltage External Setting)

Chip

Resistance

Inductor

20/33

For the VIN, VOUT, VSS, CE, please put the wire.

■TEST CIRCUITS

< Circuit No.1 > ・A/B/C/E/G series ・D/F series

A

CIN

VIN Lx

CE/MODE VOUT

VSS

Wave Form Measure Point

L

CL

RL

V

※ Exte rnal Components

L : 1.5uH(NR3015) 3.0MHz

4.7uH(NR4018) 1.2MHz

CIN : 4.7μF(ceramic) CL :10μF(ceramic)

< Circuit No.2 >

A

1uF

VIN Lx

VSS

VOUT

(FB)

CE/MODE

< Circuit No.3 >

< Circuit No.4 >

< Circuit No.5 >

1uF

VIN Lx

VSS

VOUT

(FB)

CE/MODE

V

100mA

ON resistance = (VIN-VLx)/100mA

< Circuit No.6 >

1uF

VIN Lx

VSS

VOUT

(FB)

CE/MODE

Wave Form Measure Point

V

ILIM

< Circuit No.7 >

< Circuit No.8 >

1uF

VIN Lx

VSS

VOUT

(FB)

CE/MODE

ILx

A

< Circuit No.9 >

A

※ Exte rnal Components

L : 1.5μH(NR4018) 3.0MHz V : 4.7μH (NR3015) 1.2MH z CIN : 4.7μF CL : 10μF R1 : 150kΩ R2 : 300kΩ Cfb : 120pF

1uF

A

VIN Lx

CIN

CE/MODE

1uF

ICEH

A

ICEL

1uF

CIN

VIN Lx

CE/MODE

VIN Lx

CE/MODE

VIN Lx

CE/MODE

VIN Lx

CE/MODE

VSS

OUT=VFB×(R1+R2)/R2

VSS

XC9235/XC9236/XC9237

Series

Wave Form Measure Point

FB

VOUT

(FB)

L

R1

R2

Wave Form Measure Point

Rpulldown 200Ω

IOUT

Cfb

CL

V

RL

A

VOUT

(FB)

Wave Form Measure Point

VOUT

(FB)

VOUT

(FB)

Ilat

Rpulldown 1Ω

21/33

)

XC9235/XC9236/XC9237

Series

■TYPICAL PERFORMANCE CHARACTERISTICS

(1) Efficiency vs. Output Current

Efficiency: EFFI (%)

Efficency:EFFI(%

L=4.7μH (NR4018), CIN=4.7μF, C L = 1 0μF

PWM/ PFM A ut omat ic Sw i t c h ing Contr ol

100

90

80

70

60

50

40

30

20

10

0

VIN= 4.2V

3.6V

2.4V

0.1 1 10 100 1000

(2) Output Voltage vs. Output Current

L=4.7μH (NR4018), CIN=4.7μF, C L = 1 0μF

2.1

XC9237A18C

PWM Control VIN= 4.2V

3.6V

2.4V

Output Current: IOUT (mA)

Output Current:IOUT(mA)

XC9237A18C

L=1.5μH (NR3015), CIN=4.7μF, C L = 1 0μF

PWM/ PFM A ut omat ic Sw i t c h ing Contr ol

100

90

80

70

60

50

40

Efficency:EFFI( %

30

Efficiency: EFFI (%)

20

10

0

0.1 1 10 100 1000

2.1

VIN= 4.2V

3.6V

2.4V

L=1.5μH (NR3015), CIN=4.7μF, C L = 1 0μF

XC9237A18D

PWM Control VIN= 4.2V

3.6V

2.4V

Output Current: IOUT (mA)

Output Current:IOUT(mA)

XC9237A18D

2.0

1.9

1.8

1.7

Output Voltage: VOUT (V)

Output Voltage:Vout(V)

1.6

1.5

0.1 1 10 100 1000

PWM/ PFM A ut omat ic Sw i t c h ing Contr ol

Output Current: IOUT (mA)

Output Current:IOUT(mA)

VIN＝4.2V,3.6V ,2.4V

PWM C o n t r ol

(3) Ripple Voltage vs. Output Current

L=4.7μH (NR4018), CIN=4.7μF, C L = 1 0μF

100

80

60

PWM Control

40

VIN＝4.2V,3.6V ,2.4V

Ripple Voltage:Vr(mV)

Ripple Voltage: Vr (mV)

20

XC9237A18C

PWM/ PFM A ut o ma t i c Sw itching Control VIN＝4.2V

3.6V

　　2.4V

2.0

1.9

1.8

1.7

Output Voltage:Vout(V)

1.6

1.5

0.1 1 10 100 1000

100

80

60

40

Ripple Voltage:Vr(mV)

Ripple Voltage: Vr (mV)

20

PWM/PFM Automatic Sw itching Control

Output Current: IOUT (mA)

Output Current:IOUT(mA)

L=1.5μH (NR3015), CIN=4.7μF, C L = 1 0μF

PWM Control VIN＝4.2V,3.6V ,2.4V

VIN＝4.2V,3.6V ,2.4V

PWM Control

XC9237A18D

PWM/PFM Automatic Sw itching Control VIN＝4.2V

3.6V

　　2.4V

0

0.1 1 10 100 1000

Output Current: IOUT (mA)

Output Current:IOUT(mA)

0

0.1 1 10 100 1000

Output Current: IOUT (mA)

Output Current:IOUT(mA)

22/33

)

XC9235/XC9236/XC9237

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(4) Oscillation Frequency vs. Ambient Temperature

L=4.7μH (NR4018), CIN=4.7μF, C L = 1 0μF

1.5

1.4

1.3

1.2

1.1

1.0

0.9

Oscillation Frequency: FOSC (MHz)

Oscillation Frequency : FOSC(MHz)

0.8

-50 -25 0 25 50 75 100

XC9237A18C

VIN=3.6V

Ambient Temperature: Ta (℃)

L=1.5μH (NR3015), CIN=4.7μF, C L = 1 0μF

3.5

3.4

3.3

3.2

3.1

3.0

2.9

2.8

2.7

Oscillation Frequency: FOSC (MHz)

Oscillation Frequency : FOSC(MHz)

2.6

2.5

-50 -25 0 25 50 75 100

(5) Supply Current vs. Ambient Temperature

40

35

30

25

20

15

10

Supply Current: IDD (μA)

Supply Current : IDD (μA

5

0

-50 -25 0 25 50 75 100

VIN=2.0V

XC9237A18C

VIN=6.0V

VIN=4.0V

Ambient Temperature: Ta (℃)

40

35

30

25

20

15

10

Supply Current : IDD (μA

Supply Current: IDD (μA)

VIN=2.0V

5

0

-50-250 255075100

(6) Output Voltage vs. Ambient Temperature (7) UVLO Voltage vs. Ambient Temperature

2.1

2.0

XC9237A18D

1.8

1.5

XC9237A18D

VIN=3.6V

Ambient Temperature: Ta (℃)

XC9237A18D

VIN=4.0V

Ambient Temperature: Ta (℃)

XC9237A18D

VIN=6.0V

CE=V IN

Series

1.9

1.8

1.7

Output Voltage: VOUT (V)

Output Voltage : VOUT (V)

1.6

1.5

-50-250 255075100

VIN=3.6V

Ambient Temperature: Ta (℃)

1.2

0.9

0.6

UVLO Voltage: UVLO (V)

UVLO Voltage : UVLO (V)

0.3

0.0

-50-250 255075100

Ambient Temperature: Ta (℃)

23/33

)

XC9235/XC9236/XC9237

Series

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(8) CE "H" Voltage vs. Ambient Temperature (9) CE "L" Voltage vs. Ambient Temperature

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

CE "H " Voltage : VC EH ( V

CE “H” Voltage: VCEH (V)

0.2

0.1

0.0

-50 -25 0 25 50 75 100

XC9237A18D

VIN=5.0V

VIN=2.4V

Ambient Temperature: Ta (℃)

VIN=3.6V

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

CE “L” Voltage: VCEL (V)

CE "L" Voltage : VCEL (V)

0.2

0.1

0.0

-50 -25 0 25 50 75 100

XC9237A18D

VIN=5.0V

VIN=3.6V

VIN=2.4V

Ambient Temperature: Ta (℃)

(10) Soft Start Time vs. Ambient Temperature

L=4.7μH (NR4018), CIN=4.7μF, C L = 1 0μF

5

XC9237A18C

L=1.5μH (NR3015), CIN=4.7μF, C L = 1 0μF

XC9237A18D

5

4

3

2

Soft Start Time: TSS (ms)

Soft Start Time : TSS (ms

1

0

-50-25 0 255075100

VIN=3.6V

Ambient Temperature: Ta (℃)

4

3

2

Soft Start Time: TSS (ms)

Soft Start Time : TSS (ms

1

0

-50 -25 0 25 50 75 100

VIN=3.6V

Ambient Temperature: Ta (℃)

(11) "Pch / Nch" Driver on Resistance vs. Input Voltage

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

Lx SW ON Res istanc e:RLxH,RLxL ( Ω)

0.1

Lx SW ON Resistance: RLxH, RLxL (Ω)

0.0 0123456

XC9237A18D

Nch on Resistance

Pch on Resistanc e

Input Voltage : VIN (V)

Input Voltage: VIN (V)

24/33

A

XC9235/XC9236/XC9237

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(12) XC9235B/36B/37B Rise Wave Form

L=4.7μH (NR4018), CIN=4.7μF, C L = 1 0μF

XC9237B12C

L=1.5μH (NR3015), CIN=4.7μF, C L = 1 0μF

XC9237B33D

Series

VIN=5.0V

IOUT=1.0m

VOUT：0.5V/div

100μs/div 100μs/div

(13) XC9235B/36B/37B Soft-Start Time vs. Ambient Temperature

XC9237B12C XC9237B33D

L=4.7μH(NR4018), CIN=4.7μF, C L = 1 0 μF L=1.5μH(NR3015), CIN=4.7μF, C L = 10 μF

500

400

300

VIN=5.0V

IOUT=1.0m

VOUT：1.0V/div

CE：0.0V⇒1.0V CE：0.0V⇒1.0V

500

400

300

200

Soft Start Time :TSS (μs)

VIN=5.0V IOUT=1. 0m A

100

0

-50 -25 0 25 50 75 100

Ambient Temperature: Ta(℃)

200

VIN=5.0V

Soft Start Time :TSS (μs)

IOUT=1.0m A

100

0

-50 -25 0 25 50 75 100

Ambient Temperature: Ta(℃)

(14) XC9235B/36B/37B CL Discharge Resistance vs. Ambient Temperature

XC9237B33D

600

500

400

300

200

CL Discharge Resistance: (Ω)

100

-50 -25 0 25 50 75 100

Ambient Temperature: Ta (℃)

VIN=6.0V

VIN=4.0V

VIN=2.0V

25/33

XC9235/XC9236/XC9237

Series

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(15) Load Transient Response

XC9237A18C

L=4.7μH (NR4018), C

=3.6V, VCE=VIN (PWM/PFM Automatic Switching Control)

V

IN

=1mA → 100mA I

I

OUT

1ch: I

V

: 50mV/div V

OUT

I

=100mA → 1mA I

OUT

1ch: I

V

: 50mV/div V

OUT

1ch: I

OUT

2ch 2ch

1ch: I

OUT

2ch 2ch

=4.7μF (ceramic), CL=10μF (ceramic), Topr=25℃

IN

50μs/div 50μs/div

200μs/div 200μs/div

=1mA → 300mA

OUT

: 50mV/div

OUT

=300mA → 1mA

OUT

: 50mV/div

OUT

26/33

XC9235/XC9236/XC9237

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(15) Load Transient Response (Continued)

XC9237A18C

L=4.7μH (NR4018), C

=3.6V, VCE=1.8V (PWM Control)

V

IN

=1mA → 100mA I

I

OUT

1ch: I

OUT

2ch 2ch

V

: 50mV/div V

OUT

I

=100mA → 1mA I

OUT

1ch: I

OUT

2ch 2ch

V

: 50mV/div V

OUT

=4.7μF (ceramic), CL=10μF (ceramic), Topr=25℃

IN

50μs/div 50μs/div

200μs/div 200μs/div

=1mA → 300mA

OUT

: 50mV/div

OUT

=300mA → 1mA

OUT

: 50mV/div

OUT

Series

27/33

XC9235/XC9236/XC9237

Series

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(15) Load Transient Response (Continued)

XC9237A18D

L=1.5μH (NR3015), C

=3.6V, VCE=VIN (PWM/PFM Automatic Switching Control)

V

IN

=1mA → 100mA I

I

OUT

1ch: I

V

: 50mV/div V

OUT

I

=100mA → 1mA I

OUT

1ch: I

: 50mV/div V

V

OUT

1ch: I

OUT

2ch 2ch

1ch: I

OUT

2ch 2ch

=4.7μF (ceramic), CL=10μF (ceramic), Topr=25℃

IN

50μs/div 50μs/div

200μs/div 200μs/div

=1mA → 300mA

OUT

: 50mV/div

OUT

=300mA → 1mA

OUT

: 50mV/div

OUT

28/33

XC9235/XC9236/XC9237

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(15) Load Transient Response (Continued)

XC9237A18D

L=1.5μH (NR3015), C

=3.6V, VCE=1.8V (PWM Control)

V

IN

=1mA → 100mA I

I

OUT

1ch: I

V

: 50mV/div V

OUT

I

=100mA → 1mA I

OUT

1ch: I

: 50mV/div V

V

OUT

1ch: I

OUT

2ch 2ch

1ch: I

OUT

2ch 2ch

=4.7μF (ceramic), CL=10μF (ceramic), Topr=25℃

IN

50μs/div 50μs/div

200μs/div 200μs/div

=1mA → 300mA

OUT

: 50mV/div

OUT

=300mA → 1mA

OUT

: 50mV/div

OUT

Series

29/33

XC9235/XC9236/XC9237

Series

■PACKAGING INFORMATION

●SOT-25

●USP-6C Reference Pattern Layout

0.05

2.4

0.45

6

5

4

0.05

1.0

0.45

1

2

3

●USP-6C

●USP-6C Reference Metal Mask Design

30/33

■PACKAGING INFORMATION (Continued)

●USP-6EL

* A part of the pin may appear from the side of the package because of it’s

structure, but reliability of the package and strength will not be changed below the

standard.

●USP-6EL Reference Pattern Layout

0.35

0.3750.375

1.5

0.55 0.55

1.1

2.25

XC9235/XC9236/XC9237

●USP-6EL Reference Metal Mask Design

1.4

0.3

0.5

0.30.3

0.9

0.55 0.55

Series

2.2

31/33

XC9235/XC9236/XC9237

■MARKING RULE

●SOT-25

SOT-25

(TOP VIEW)

USP-6C/USP-6EL

(TOP VIEW)

① represent product series

② represents integer number of output voltage and oscillation frequency

●A/B/C/F Series

VOLTAGE (V)

●E/G/D Series

VOLTAGE (V)

③ represents decimal point of output voltage

④⑤ represents production lot number

Order of 01, …09, 10, 11, …99, 0A, …0Z, 1A, …9Z, A0, …Z9, AA, …ZZ. (G, I, J, O, Q, W excluded) *No character inversion used.

Series

PRODUCT

SERIES

XC9235 XC9236 XC9237

A 4 5 6 B C D E C K L M D K L M E 4 5 6

F 2 7 B

G C D E

MARK OUTPUT

f

=1.2MHz f

OSC

=3.0MHz

OSC

0.X A F

1.X B H

2.X C K

3.X D L

4.X E M

OUTPUT

f

=1.2MlHz f

OSC

MARK

=3.0MlHz

OSC

0.X N U

1.X P V

2.X R X

3.X S Y

4.X T Z

V

(V) MARK V

OUT

(V) MARK

OUT

X.00 0 X.05 A X.10 1 X.15 B X.20 2 X.25 C X.30 3 X.35 D X.40 4 X.45 E X.50 5 X.55 F X.60 6 X.65 H X.70 7 X.75 K X.80 8 X.85 L X.90 9 X.95 M

32/33

XC9235/XC9236/XC9237

Series

1. The products and product specifications contained herein are subject to change without

notice to improve performance characteristics. Consult us, or our representatives

before use, to confirm that the information in this datasheet is up to date.

2. We assume no responsibility for any infringement of patents, patent rights, or other

rights arising from the use of any information and circuitry in this datasheet.

3. Please ensure suitable shipping controls (including fail-safe designs and aging

protection) are in force for equipment employing products listed in this datasheet.

4. The products in this datasheet are not developed, designed, or approved for use with

such equipment whose failure of malfunction can be reasonably expected to directly

endanger the life of, or cause significant injury to, the user.

(e.g. Atomic energy; aerospace; transport; combustion and associated safety

equipment thereof.)

5. Please use the products listed in this datasheet within the specified ranges.

Should you wish to use the products under conditions exceeding the specifications,

please consult us or our representatives.

6. We assume no responsibility for damage or loss due to abnormal use.

prior permission of TOREX SEMICONDUCTOR LTD.

33/33

TOREX XC9235, XC9236, XC9237 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual