TOREX XC9254R User Manual

XC9254R Series

ETR0529-002

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

☆GreenOperation Compatible

■GENERAL DESCRIPTIO N

The XC9254R series is a group of synchronous-rectification type DC/DC converters with a built-in 0.42ΩP-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. The XC9254R001 type has a fixed output voltage of 1.2V (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, 1.2MHz is fixed internally. As for operation mode, the XC9254 R series is
automatic PWM/PFM switching control 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. 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.
Two types of package SOT-25 and USP-6C are available.

■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

■TYPICAL APPLICA TION CIRCUIT

■FEATURES

Driver Transistor Built-In

Input Voltage : 2.0V ~ 6.0V
Output Voltage : 1.2V
High Efficiency : 92% (TYP.)
Output Current : 600mA
Oscillation Frequency : 1.2MHz (+15%)
Maximum Duty Cycle : 100%
Control Methods : PWM/PFM Auto
Function : Current Limiter Circuit Built-In

C
Capacitor

Operating Ambient Temperature
Packages : SOT-25, USP-6C

Environmentally Friendly : EU RoHS Compliant, Pb Free

* Performance depends on external components and wiring on the PCB.

: 0.42Ω P-ch driver transisto r

0.52Ω N-ch switch transistor

(Constant Current & Latching)

Discharge

L

: Low ESR Ceramic Capacitor
: -40℃ ～ +85℃

CE

1/17

XC9254R Series

■PIN CONFIGURATION

Lx VOUT

5 4

132

VSS CE/MODEVIN

CE/MODE 4

VIN 6

VSS 5

CE

1 Lx

2 VSS

3 VOUT (FB)

SOT-25

(Top View)

■PIN ASSIGNMENT

PIN NUMBER

SOT-25 USP-6C

1 6 VIN Power Input
2 2, 5 VSS Ground
3 4 CE High Active Enable
4 3 VOUT Fixed Output Voltage Pin
5 1 Lx Switching Output

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
to other pins, it should be connected to the V

(No. 5) pin.

SS

PIN NAME FUNCTION

2/17

■PRODUCT CLASSIFICATION

●Ordering Information

PWM / PFM automatic switching control

(*1)

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

PRODUCT NAME PACKAGE (ORDER UNIT)

XC9254R001MR-G

XC9254R001ER-G

(*1)

SOT-25 (3,000/Reel)

(*1)

USP-6C (3,000/Reel)

XC9254R

Series

3/17

A

XC9254R Series

■BLOCK DIAGRAM

VOUT

VIN

VSS

R2

R1

CFB

Error Amp.

FB

VSHORT

Vref with
Soft Start,
CE

UVLO

R3

R4

Phase
Compensation

PWM/PFM
Selector

UVLO Cmp

PWM
Comparator

Current Feedback
Current Limit

Logic

CE
Control
Logic

Synch
Buffer
Drive

Ramp Wave
Generator
OSC

Lx

CE/

CE

NOTE:

■

The signal from CE Control Logic to PWM/PFM Selector is being fixed to "H" level inside,
and XC9254R series chooses only PWM/PFM automatic switching control.
Diodes inside the circuit are ESD protection diodes and parasitic diodes.

BSOLUTE MAXIMUM RATINGS

PARAMETER SYMBOL RATINGS UNIT

VIN Pin Voltage VIN - 0.3 ~ 6.5 V

Lx Pin Voltage VLx - 0.3 ~ VIN + 0.3 ≦ 6.5V V

V

Pin Voltage V

OUT

CE Pin Voltage VCE - 0.3 ~ 6.5 V

Lx Pin Current ILx ±1500 mA

SOT-25 250 Power Dissipation

(*Ta=25℃)

USP-6C

Operating Ambient Temperature Topr - 40 ~ + 85

Storage Temperature Tstg - 55 ~ + 125

- 0.3 ~ 6.5 V

OUT

Pd

100

Ta=25℃

mW

O

C

O

C

4/17

XC9254R

■ELECTRICAL CHARACTERISTICS (Continued)

XC9254R Series, V

PARAMETER SYMBOL CONDITIONS MIN. TYP. MAX. UNIT

Output Voltage V

Operating Voltage Range VIN 2.0 - 6.0 V ①

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

CE "H" Current I

CE "L" Current I
Soft Start Time tSS

Latch Time t

Short Protection Threshold

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

Voltage

CL Discharge R

*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: Time until it short-circuits V
*7: When V
*8: When the difference between the input and the output is small, some cycles may be skipped completely before current maximizes.

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

*10: “H”=V

*11: V

IN

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

IN~VIN

is applied when V

IN

=1.2V, f

OUT

(*2)

EFFI

(*5)

I

(*9)

I

IN

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

-1.2V, “L”=+0.1V~-0.1V

OUT (E)

=1.2MHz, Ta=25℃

OSC

When connected to external components,

DTY

DTY

OUT

OUTMAX

UVLO

STB

OSC

PFM

LIMIT_PFM

DTY

V

=5.0V, I

IN=VCE

V

IN=VOUT(E)

When connected to external components

=VIN, V

V

CE

Voltage which Lx pin holding “L” level

=5.0V, V

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)

=2.0V, I

V

CE=VIN

V

MAX

MIN

IN=VCE

V

IN=VCE

=5.0V, V
=5.0V, V

=30mA

OUT

+2.0V, VCE=1.0V,

OUT=VOUT(E)

×0.5V

OUT=VOUT(E)

OUT=VOUT(E)

+2.0V, VCE =1.0V, I

+2.0V, VCE =VIN, I

=1mA 200 % ①

OUT

OUT=VOUT(E)
OUT=VOUT(E)

(*8)

(*11)

(*1, *10)

×1.1V - 15 33 μA ③

×1.1V - 0 1.0 μA ③

=100mA

OUT

=1mA

OUT

×0.9V 100 - - % ②
×1.1V - - 0 % ②

When connected to external components,

(V

V

CE=VIN=VOUT(E)

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

V

LIM

△V

OUT

・△Topr)

OUT

CEH

CEL

VIN=VCE=5.0V,

CEH

VIN=5.0V, VCE=0V,

CEL

IN=VCE

/

I

OUT

V

OUT

Voltage changes Lx to “H” level
V

OUT

Voltage changes Lx to “L” level

OUT

=30mA, -40℃≦Topr≦85℃ - ±100 -

=

V

=

V

+1.2V, I

OUT (E)

OUT (E)

(*4)

- 0.45 0.66 Ω ④

(*4)

=100mA

OUT

×0.9V , ILx=100mA
×0.9V , ILx=100mA

(*3)

(*3)

=5.0V, VCE=0V, Lx=0V - 0.01 1.0 μA ⑤

=5.0V, V

OUT(E)

OUT(E)

OUT=VOUT(E)

×0.9V, Applied voltage to VCE,

×0.9V, Applied voltage to VCE ,

V

=

V

OUT

OUT(E)

V

=

V

OUT

OUT(E)

(*7)

×0.9V

900 1050 1350 mA ⑥

(*10)

(*10)

×0.9V - 0.1 - 0.1 μA ⑤

×0.9V - 0.1 - 0.1 μA ⑤

When connected to external components,
V

=0V → VIN, I

CE

=5.0V, V

V

LAT

IN=VCE

Short Lx at 1Ω resistance
Sweeping V

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

x 0.5V becomes more than VIN.

1

Ω

resistance, V

level within 1ms

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

=Nominal Voltage, applied voltage sequence is V

OUT(E)

=1mA

OUT

=0.8×V

OUT

, VIN=VCE=5.0V, Short Lx at

OUT

voltage which Lx becomes “L”

OUT

,

OUT(E)

(*6)

=open 200 300 450 Ω ⑧

OUT

1.176 1.200 1.224 V ①

600 - - mA ①

1.00 1.40 1.78 V ②

1020 1200 1380 kHz ①

140 180 240 mA ①

- 92 - % ①

- 0.35 0.55 Ω ④

- 0.42 0.67 Ω ④

- 0.52 0.77 Ω -

0.65 - 6.0 V ③

V

SS

0.5 1.0 2.5 ms ①

1.0 - 20.0 ms ⑦

0.675 0.900 1.150 V ⑦

OUT→VIN→VCE

ppm/

- 0.25 V ③

℃

Series

CIRCUIT

①

5/17

XC9254R Series

■TYPICAL APPLICATION CIRCUIT

V

OUT

600mA

C

L

(ceramic)

L

Lx

VSS

VOUT

V

VSS

CE/

CE

MODE

IN

V

C

IN

(ceramic)

CE/ MO DE

CE

●f

=1.2MHz

OSC

L:

CL:

4.7μH

4.7μF
10μF

IN

CIN:

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

6/17