TOREX XCL201, XCL202 User Manual

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XCL201/XCL202 Series

ETR2802-003

Inductor Built-in Step-Down “micro DC/DC” Converters

■GENERAL DESCRIPTION

The XCL201/XCL201 series is a synchronous step-down micro DC/DC converter which integrates an inductor and a control IC in one tiny package (2.5mm×2.0mm, h=1.0mm). A stable power supply with an output current of 400mA is configured using only two capacitors connected externally. Operating voltage range is from 2.0V to 6.0V. Output voltage is internally set in a range from 0.8V to 4.0V in increments of

0.05V. The device is operated by 1.2MHz, and includes 0.42ΩP-channel driver transistor and 0.52ΩN-channel switching transistor. As for operation mode, the XCL201 series is PWM control, the XCL202 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). During stand-by, the device is 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 driver transistor is forced OFF when input voltage becomes 1.4V or lower. The series provide short-time turn-on by the soft start function internally set in 0.25ms (TYP). The series integrate C discharge function which enables the electric charge stored at the output capacitor C auto-discharge switch located between the LX and VSS pins. When the devices enter stand-by mode, output voltage quickly returns to the V

■APPLICATIONS

●Mobile phones, Smart phones

●Bluetooth Headsets

●WiMAX PDAs, MIDs, UMPCs

●Portable game consoles

●Digital cameras, Camcorders

●SSD(Solid State Drive)

●PND(Portable Navigation Device)

TYPICAL APPLICATION CIRCUIT

10μF

400mA

* “L1 and L

level as a result of this function.

XCL201/XCL202 Series

Vss

OUT

(TOP VIEW)

”, and “L2 and V

VIN

Vss

” is connected by wiring.

OUT

4.7μF

■FEATURES

Ultra Small : 2.5mm×2.0mm, h=1.0mm

Input Voltage : 2.0V ~ 6.0V Output Voltage : 0.8V ~ 4.0V (±2.0%)

High Efficiency : 92%(VIN=4.2V,V

Output Current : 400mA Oscillation Frequency : 1.2MHz (±15%)

Maximum Duty Cycle : 100%

Output Capacitor : Low ESR Ceramic

Current Limiter Circuit : Constant Current & Latching

Control Methods : PWM (XCL201)

PWM/PFM Auto (XCL202)

CE Function : Soft-Start Circuit Built-In

Operating Ambient Temperature

Environmentally Friendly : EU RoHS Compliant, Pb Free

TYPICAL PERFORMANCE

CHARACTERISTICS

100

Efficency:EFFI(%



to be discharged via the internal

XCL201B331BR/XCL202B331BR

XCL202(PWM/PFM)

4.2V

0.01 0.1 1 10 100 1000

☆GreenOperation Compatible

: -40℃〜+85℃

VIN = 5.5V

5.0V

Output Curr ent:I

XCL201(PWM)

VOUT=3.3V

(mA)

OUT

auto

OUT

=3.3V)

1/21

XCL201/XCL202 Series

■PIN CONFIGURATION

Vss

(BOTTOM VIEW)

■PIN ASSIGNMENT

Vss

VOUT

* It should be connected the VSS pin (No. 2 and 5) to the GND pin.

* If the dissipation pad needs to be connected to other pins, it should be connected to the GND pin.

* Please refer to pattern layout page for the connecting to PCB.

PIN NUMBER PIN NAME

FUNCTION

1 Lx Switching Output

2,5 VSS Ground

3 V

Output Voltage

OUT

4 CE Chip Enable 6 VIN Power Input 7 L1 8 L2

Inductor Electrodes

■PRODUCT CLASSIFICATION

●Ordering Information XCL201①②③④⑤⑥-⑦ XCL202①②③④⑤⑥-⑦

(*1)

Fixed PWM control

(*1)

PWM / PFM automatic switching control

DESIGNATOR ITEM SYMBOL DESCRIPTION

①

②③

Functions selection B C

Output Voltage

(*2)

auto discharge, High speed soft-start

10 1.0V 12 1.2V 15 1.5V

18 1.8V 25 2.5V 28 2.8V 30 3.0V 33 3.3V

④

⑤⑥-⑦

(*1)

The “-G” suffix denotes Halogen and Antimony free as well as being fully RoHS compliant.

(*2)

When other output voltages are needed, please contact your local Torex sales office for more information.

Output voltage range is 0.8~4.0V.

(*1)

Oscillation Frequency 1 1.2MHz

Package

(Order Unit)

BR-G CL-2025 (3,000/Reel)

2/21

■BLOCK DIAGRAM



●XCL201B / XCL202B Series

XCL201/XCL202

Series

L2 L1

VOUT

CFB

VIN

Vref with

Soft Start,

UVLO

VSHORT



Phase

Compensation

Error Amp.

PWM/PFM

Selector

UVLO Cmp

Inductor

Current Feedback

PWM

Comparator

Current Limit

Logic

Ramp Wave

Generator

OSC

Control

Logic

Synch Buffer

Drive

VSS

CE/

NOTE: The XCL201 offers a fixed PWM control, a signal from CE Control Logic to PWM/PFM Selector is fixed to "L" level inside. The

XCL202 control scheme is PWM/PFM automatic switching, a signal from CE Control Logic to PWM/PFM Selector is fixed to "H" level

inside. The diodes placed inside are ESD protection diodes and parasitic diodes.

■ABSOLUTE MAXIMUM RATINGS

Ta = 2 5 ℃

PAR AMET ER SYMBOL RATINGS UNITS

VIN Pin Voltage VIN - 0.3 ~ 6.5 V

LX Pin Voltage VLX - 0.3 ~ V

Pin Voltage V

OUT

- 0.3 ~ 6.5 V

OUT

CE Pin Voltage VCE - 0.3 ~ 6.5 V

LX Pin Current I

±1500 mA

Power Dissipation Pd 1000 *1 mW

Operating Ambient Temperature Topr - 40~ +85 ℃

Storage Temperature Tstg - 40 ~ +105 ℃

*1: The power dissipation figure shown is PCB mounted (40mm×40mm, t=1.6mm, Glass Epoxy FR-4).

Please refer to page 12 for details.

+ 0.3≦6.5 V

3/21

XCL201/XCL202 Series

■ELECTRICAL CHARACTERISTICS

XCL201B121BR/XCL202B121BR, V

OUT

=1.2V, f

=1.2MHz, Ta=25℃

OSC

PARAMETER SYMBOL CONDITIONS

Output Voltage V

Operating Voltage Range

Maximum Output Current

UVLO Voltage V

Supply Current (XCL201) - 22 50

Supply Current (XCL202)

Stand-by Current I

Oscillation Frequency

PFM Switching Current

PFM Duty Limit

(*11)

DTY

OUT

OUTMAX

UVLO

STB

OSC

PFM

LIMIT_PFM

Maximum Duty Cycle MAXDTY VIN=VCE=5.0V, V

Minimum Duty Cycle MINDTY VIN=VCE=5.0V, V

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" Leakage 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

Latch Time

Short Protection

Threshold Voltage

CL Discharge

Inductance Value

Allowed Inductor Current I

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)=(VIN - Lx pin measurement voltage) / 100mA

(*4)

Design value

(*5)

When temperature is high, a current of approximately 10μA (maximum) may leak.

(*6)

Time until it short-circuits V

(*7)

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

(*8)

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.

(*9)

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

(*10)

“H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V

(*11)

and DTY

PFM

(*2)

EFFI

LｘH1

LｘH2

LｘL1

(*5)

(*9)

LｘL2

LeakH

LIM

△

OUT

・△

OUT

CEH

CEL

CEH

CEL

LAT

SHORT

DCHG

L Test frequency=1MHz - 4.7 - μH-

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

OUT

are defined only for the XCL202 series which have PFM control function. (Not for the XCL201 series)

LIMIT_PFM

When connected to external components, V

IN=VCE

=5.0V, I

OUT

=30mA

2.0 - 6.0 V ①

IN=VOUT(T)

When connected to external components V

CE=VIN,VOUT

Voltage which Lx pin holding “L” level

IN=VCE

VIN=5.0V, VCE=0V, V

When connected to external components, V

IN=VOUT(T)

When connected to external components, V

IN=VOUT(T)

VCE=VIN = 2.0V, I

+2.0V, VCE=1.0V

=0V

=5.0V, V

OUT=VOUT(T)

OUT

+2.0V, VCE=1.0V , I

+2.0V, VCE=VIN , I

=1mA - 200 300 % ①

OUT

OUT=VOUT (T)

When connected to external components, V

CE=VIN=VOUT (T)

VIN=VCE=5.0V, V VIN=VCE=3.6V, V VIN=VCE=5.0V VIN=VCE=3.6V

VIN=V

Topr)

OUT

IN=VCE

=30mA

OUT

-40℃≦Topr≦85℃

=0V, Applied voltage to VCE,

OUT

Voltage changes Lx to “H” level V

=0V, Applied voltage to VCE,

OUT

Voltage changes Lx to “L” level VIN=VCE=5.0V, V V

=5.0V, VCE=0V, V

When connected to external components,

=0V→V

IN=VCE

Short Lx at 1Ω resistance

Sweeping V

1Ω resistance, V

level within 1ms

+1.2V, I

=0V,ILX=100mA

OUT

=0V,ILX=100mA

OUT

(*4)

- 0.45 0.66 Ω -

(*4)

- 0.52 0.77 Ω -

=5.0V, VCE=0V, LX=0V - 0.01 1.0 μA ⑨

=5.0V, V

OUT=VOUT (T)

=0V - 0.1 - 0.1 μA ⑤

OUT

, I

=1mA

OUT

=0.8×V

OUT

, VIN=VCE=5.0V, Short Lx at

OUT

voltage which Lx becomes “L”

OUT

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

ΔT=40℃ - 600 - mA -

=Nominal Voltage

OUT(T)

(*8)

(*1, *10)

×1.1V

= V

×1.1V - 0 1.0 μA ③

OUT(T)

=100mA

OUT

=1mA

OUT

×0.9V 100 - - % ③ ×1.1V - - 0 % ③

=100mA

OUT

×0.9V

(*10)

(*3)

- 0.35 0.55 Ω ④

(*3)

- 0.42 0.67 Ω ④

(*7)

700 800 1000 mA ⑥

=0V - 0.1 - 0.1 μA ⑤

OUT(T)

(*6)

=open 200 300 450 Ω ⑧

OUT

MIN. TYP. MAX.

1.176 1.200 1.224 V ①

400 - - mA ①

1.00 1.40 1.78 V ②

- 15 33

1020 1200 1380 kHz ①

140 180 240 mA ⑩

- 86 - % ①

- ±100 - ppm/ ℃ ①

0.65 - 6.0 V ③

- 0.25 V ③

- 0.25 0.40 ms ①

1.0 - 20 ms ⑦

0.450 0.600 0.750 V ⑦

UNITS

CIRCUIT

μA ②

4/21

■ELECTRICAL CHARACTERISTICS (Continued)

XCL201B181BR/XCL202B181BR, V

OUT

=1.8V, f

=1.2MHz, Ta=25℃

OSC

XCL201/XCL202

Series

PARAMETER SYMBOL CONDITIONS

Output Voltage V

Operating Voltage Range

Maximum Output Current

UVLO Voltage V

Supply Current (XCL201) - 22 50

Supply Current (XCL202)

Stand-by Current I

Oscillation Frequency

PFM Switching Current

PFM Duty Limit

(*11)

DTY

OUT

OUTMAX

UVLO

STB

OSC

PFM

LIMIT_PFM

Maximum Duty Cycle MAXDTY VIN=VCE=5.0V, V

Minimum Duty Cycle MINDTY VIN=VCE=5.0V, V

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" Leakage 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

Latch Time

Short Protection

Threshold Voltage

CL Discharge

Inductance Value

Allowed Inductor Current I

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)=(VIN - Lx pin measurement voltage) / 100mA

(*4)

Design value

(*5)

When temperature is high, a current of approximately 10μA (maximum) may leak.

(*6)

Time until it short-circuits V

(*7)

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

(*8)

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.

(*9)

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

(*10)

“H”=VIN~VIN-1.2V, “L”=+0.1V~-0.1V

(*11)

and DTY

PFM

(*2)

EFFI

LｘH1

LｘH2

LｘL1

(*5)

(*9)

LｘL2

LeakH

LIM

△

OUT

・△

OUT

CEH

CEL

CEH

CEL

LAT

SHORT

DCHG

L Test frequency=1MHz - 4.7 - μH-

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

OUT

are defined only for the XCL202 series which have PFM control function. (Not for the XCL201 series)

LIMIT_PFM

When connected to external components, V

IN=VCE

=5.0V, I

OUT

=30mA

2.0 - 6.0 V ①

IN=VOUT(E)

When connected to external components V

CE=VIN,VOUT

Voltage which Lx pin holding “L” level

IN=VCE

VIN=5.0V, VCE=0V, V

When connected to external components, V

IN=VOUT(T)

When connected to external components, V

IN=VOUT(T)

VCE=VIN=V

+2.0V, VCE=1.0V

=0V

=5.0V, V

OUT=VOUT(T)

+2.0V, VCE=1.0V , I

+2.0V, VCE=VIN , I

+0.5V, I

OUT(T)

OUT=VOUT (T)

(*8)

(*1, *10)

×1.1V

×1.1V - 0 1.0 μA ③

=100mA

OUT

=1mA

OUT

=1mA - 200 300 % ①

OUT

×0.9V 100 - - % ③ ×1.1V - - 0 % ③

When connected to external components, V

CE=VIN=VOUT (T)

VIN=VCE=5.0V, V VIN=VCE=3.6V, V VIN=VCE=5.0V VIN=VCE=3.6V

VIN=V

Topr)

OUT

IN=VCE

=30mA

OUT

-40℃≦Topr≦85℃

=0V, Applied voltage to VCE,

OUT

Voltage changes Lx to “H” level V

=0V, Applied voltage to VCE,

OUT

Voltage changes Lx to “L” level

IN=VCE

VIN=5.0V, VCE=0V, V

When connected to external components, V

=0V→V

IN=VCE

Short Lx at 1Ω resistance Sweeping V 1Ω resistance, V “L” level within 1ms

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

+1.2V, I

OUT

(*4)

- 0.45 0.66 Ω -

(*4)

- 0.52 0.77 Ω -

=5.0V, VCE=0V, L

= 5.0V, V

=5.0V, V

OUT=VOUT (T)

OUT

, I

OUT

, VIN=VCE=5.0V, Short Lx at

OUT

=100mA

OUT

=0V, ILX=100mA =0V, ILX=100mA

=0V - 0.1 - 0.1 μA ⑤

OUT

=1mA

=0.8×V

(*6)

voltage which Lx becomes

(*3)

- 0.35 0.55 Ω ④

(*3)

- 0.42 0.67 Ω ④

=0V - 0.01 1.0 μA ⑨

(*7)

×0.9V

OUT(T)

700 800 1000 mA ⑥

(*10)

=open 200 300 450 Ω ⑧

OUT

ΔT=40℃ - 600 - mA -

=Nominal Voltage

OUT (T)

MIN. TYP. MAX.

1.764 1.800 1.836 V ①

400 - - mA ①

1.00 1.40 1.78 V ②

- 15 33

1020 1200 1380

120 160 200 mA ⑩

- 89 - % ①

- ±100 - ppm/ ℃ ①

0.65 - 6.0 V ③

- 0.25 V ③

- 0.32 0.50 ms ①

1.0 - 20 ms ⑦

0.675 0.900 1.125 V ⑦

UNITS

CIRCUIT

μA ②

kHz ①

5/21

XCL201/XCL202 Series

■ELECTRICAL CHARACTERISTICS (Continued)

The value and conditions are depends on setting output voltage.

●PFM Switching Current (I

) (XCL202)

PFM

NOMINAL OUTPUT VOLTAGE MIN. TYP. MAX.

0.8V≦V

1.2V＜V

1.8V≦V

OUT(T)

≦1.2V ＜1.8V ≦4.0V

140mA 180mA 240mA

130mA 170mA 220mA

120mA 160mA 200mA

●PFM Duty Limit DTY

LIMIT_PFM

(XCL202)

SETTING VOLTAGE CONDITIONS

0.8V≦V

1.0V≦V

＜1.0V

OUT(T)

≦4.0V V

OUT(T)

=2.0V, I

CE=VIN

CE=VIN=VOUT(T)

=1mA

OUT

+0.5V, I

OUT

●Soft-Start Time t

 SERIES OUTPUT VOLTAGE MIN. TYP. MAX.

=1mA

- 0.25ms 0.40ms

- 0.32ms 0.50ms

- 0.28ms 0.40ms

- 0.32ms 0.50ms

- 0.28ms 0.40ms

- 0.32ms 0.50ms

XCL201B

XCL202B

0.8V≦V

1.5V≦V

1.8V≦V

2.5V≦V

0.8V≦V

2.5V≦V

OUT(T)

＜1.5V

＜1.8V

＜2.5V

≦4.0V

＜2.5V

≦4.0V

■TYPICAL APPLICATION CIRCUIT

XCL201/XCL202 Series

Vss

OUT

●External Components

: 10V/4.7μF(Ceramic)

: 6.3V/10μF(Ceramic)



NOTE:

The Inductor can be used only for this DC/DC converter.

Please do not use this inductor for the other reasons.

Please use B, X5R, and X7R grades in temperature characteristics for C

These grade ceramic capacitors minimize capacitance-loss as a function of voltage stress.

Vss

and CL capacitors.

6/21

XCL201/XCL202

Series

■OPERATIONAL DESCRIPTION

The XCL201/XCL202 series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM comparator, phase compensation circuit, output voltage adjustment resistors, P-channel MOSFET driver transistor, N-channel MOSFET switching transistor for the synchronous switch, current limiter circuit, UVLO circuit with control IC, and an inductor. (See the block diagram below.) Using the error amplifier, the voltage of the internal voltage reference source is compared with the feedback voltage from the V compensation is performed on the resulting error 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.

L2 L1

Inductor

VOUT

VIN

CFB

Vref with

Soft Start,

UVLO

Phase

Compensation

Error Amp.

VSHORT

UVLO Cmp

PWM/PFM

Selector

Current Feedback

PWM

Comparator

Current Limit

Logic

Ramp Wave

Generator

OSC

Control

Logic

Synch Buffer

Drive

VSS

CE/

<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 1.2MHz. 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 feed back voltage is lower than the reference voltage, the output voltage of the error amplifier is increased. The gain and frequency characteristics of the error amplifier output are fixed internally to deliver an optimized signal to the mixer.

pin through split resistors, R1 and R2. Phase

OUT

7/21

estart

XCL201/XCL202 Series

■OPERATIONAL DESCRIPTION (Continued)

<Current Limit> The current limiter circuit of the XCL201/XCL202 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 milliseconds 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 state. Once the IC is in suspension state, operations can be resumed by either turning the IC off via the CE pin, or by restoring power to the V therefore, the internal circuitry remains in operation. The current limit of the XCL201/XCL202 series can be set at 800mA at typical. 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, an input capacitor is placed as close to the IC as possible.

pin. The suspension state does not mean a complete shutdown, but a state in which pulse output is suspended;

Limit < # ms

Limit > # ms

Current Limit LEVEL

ILx

OUT

0mA

Vss

VIN



<Short-Circuit Protection> The short-circuit protection circuit monitors the internal R1 and R2 divider voltage from the V 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 operates to turn off and to latch the driver transistor. In the latch state, the operation can be resumed by either turning the IC off and on via the CE pin, or by restoring power supply to the V When sharp load transient happens, a voltage drop at the V may operate in the voltage higher than 1/2 V

<UVLO Circuit> When the V unstable operation of the internal circuitry. When the V 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.

pin voltage becomes 1.4V or lower, the P-channel output driver transistor is forced OFF to prevent false pulse output caused by

voltage.

OUT

pin.

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

OUT

pin voltage becomes 1.8V or higher, switching operation takes place. By releasing

flows to the driver transistor, the short-circuit protection quickly

LIM

pin (refer to FB point in the block diagram

OUT

8/21

XCL201/XCL202

Series

■OPERATIONAL DESCRIPTION (Continued)

<PFM Switch Current> In PFM control operation, until coil current reaches to a specified level (I the P-ch MOSFET is kept on can be given by the following formula.

= L×I

PFM

/ (V

−

) →IPFM①

OUT

<PFM Duty Limit> In the PFM control operation, the PFM Duty Limit (DTY

) is set to 200% (TYP.). Therefore, under the condition that the duty increases (e.g.

LIMIT_PFM

the condition that the step-down ratio is small), it’s possible for P-ch MOSFET to be turned off even when coil current doesn’t reach to IPFM. →IPFM②

tON

), the IC keeps the P-ch MOSFET on. In this case, on-time (tON) that

PFM

DTY

最大 IPFM 制限

LIMIT_PFM

ILx

PFM

0mA

ILx

OSC



①

High Speed Discharge>

PFM

The XCL201/XCL202 series can quickly discharge the electric charge at the output capacitor (C

a whole IC circuit put into OFF state, is inputted via the N-channel transistor located between the L

electric charge at the output capacitor (C

capacitor (C

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

resistance value [R] and an output capacitor value (C

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

) as τ(τ=C x R), discharge time of the output voltage after discharge via the N channel

PFM

②

) when a low signal to the CE pin which enables

transistor is calculated by the following formula.

–t/

V = V

OUT(T)

x e

or t=τln (V

OUT(T)

/ V)

V : Output voltage after discharge

: Output voltage

OUT(T)

t: Discharge time,

τ: C x R

C=Capacitance of output capacitor (C

R=C

auto-discharge resistance

100

)

Output Voltage Discharge Characteristics

=300Ω(TYP.)

DCHG

CL=10μF CL=20μF CL=50μF

PFM

0mA

pin and the VSS pin. When the IC is disabled,

100 = Setting Voltage Value

Output Voltage (Relative Value)

0 20 40 60 80 100

Discharge Time ｔ(ms)

9/21

XCL201/XCL202 Series

■OPERATIONAL DESCRIPTION (Continued)

The operation of theXCL201/XCL202 series will enter into the shut down mode when a low level signal is input to the CE 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 starts its operation by inputting a high level signal to the CE pin. The input to the CE pin is a CMOS input and the sink current is 0μA (TYP.).

●XCL20/XCL202 series - Examples of how to use CE pin

pin. The IC

OUT

<Soft Start>

Soft start time is internally set 0.25ms to 0.32ms (TYP). Soft start time is defined as the time to reach 90% of the output nominal voltage when the CE pin is turned on.



< IC inside >

VDD

SW_CE

< IC inside >

(A)

SW_CE SELECTED STATUS

ON Stand-by

OFF Operation

(B)

SW_CE SELECTED STATUS

ON Operation

OFF Stand-by

tSS

CEH

OUT

■FUNCTION CHART

CE OPERATIONAL STATES

VOLTAGE

LEVEL

(*1)

H Level

L Level

* CE pin voltage level range

(*1)

H level: 0.65V<VCE<6V

(*2)

L level: 0V<VCE<0.25V

(*3)

CE pin should not be left open to avoid unstable operation.

(*2)

Stand-by Stand-by

XCL201 XCL202

Synchronous

PWM Fixed Control

Synchronous

PWM/PFM Automatic Switching

10/21

XCL201/XCL202

Series

■NOTE ON USE

1. The XCL201/XCL202 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 input and output is large in PWM control, very narrow pulses will be outputted, and there is the possibility that some cycles may be skipped completely.

5. When the difference between input and output is small, and the load current is heavy, very wide pulses will be outputted and 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

OSC

7. When the peak current which exceeds limit current flows within the specified time, the built-in P-ch 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.

- V

) x OnDuty / (2 x L x f

OUT

: Oscillation Frequency

OSC

) + I

OUT

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

9. 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 1000mA (MAX.) at typical. However, the current of 1000mA or more may flow.

In case that the current limit functions while the V input voltage will occur at both ends of a coil. For this, the time rate of coil current becomes large. By contrast, when N-ch MOSFET is ON, there is almost no potential difference at both ends of the coil since the V rate of coil current becomes quite small. According to the 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.

①Current flows into P-ch MOSFET to reach the current limit (I ②The current of I 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.

or more flows since the delay time of the circuit occurs during from the detection of the current limit to OFF of P-ch MOSFET.

LIM

②

①

③

pin is shorted to the GND pin, when P-ch MOSFET is ON, the potential difference for

OUT

Duty

LIM

Limit > #ms

④

pin is shorted to the GND pin. Consequently, the time

OUT

⑤

LIM

ILx

11/21

XCL201/XCL202 Series

■NOTE ON USE (Continued)

14. In order to stabilize V possible to the V

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

16. When PWM/PFM automatic switching goes into continuous mode, the IC may be in unstable operation for the range of MAXDUTY area

with small input/output differential.



17. Please use within the power dissipation range below. Please also note that the power dissipation may changed by test conditions, the power dissipation figure shown is PCB mounted.

1.2

1.0

0.8

0.6

0.4

0.2

Maximum Power Disspation Pd (W)

0.0

the power loss of micro DC/DC according to the following formula:

OUT

EFFI: Conversion Efficiency (%)

0 25 50 75 100

power loss = V

: Output Voltage (V)

: Output Current (A)

Measurement Condition (Reference data)

Condition: Mount on a board

Ambient:

Soldering: Lead (Pb) free

Board: Dimensions 40 x 40 mm (1600 mm

Copper (Cu) traces occupy 50% of the board area In top and back faces Package heat-sink is tied to the copper traces

Material: Glass Epoxy (FR-4)

Thickness: 1.6mm

Through-hole: 4 x 0.8 Diameter

voltage level and oscillation frequency, we recommend that a by-pass capacitor (CIN) be connected as close as

& VSS pins.

Operating Temperature　Ta (℃)

OUT

Natural convection

((100/EFFI) – 1)(W)

OUT

in one side)

40.0

28.9

2.54

Evaluation Board (unit: mm)

1.4

28.9

40.0

2.5

12/21

XCL201/XCL202

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 (No.6) & VSS

(No.5) 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.

6. Please connect Lx (No.1) pin and L1 (No.7) pin by wiring on the PCB.

7. Please connect V

(No.3) pin and L2 (No.8) pin by wiring on the PCB.

OUT

FRONT

CIN

GNDVOUT

VINGND

VOUT

GND

VIN

BACK (Flip Horizontal)

GNDVOUT

CIN

VINGND

FRONT (PCB mounted)

13/21

XCL201/XCL202 Series

■TEST CIRCUITS

< Circuit No.1 > < Circuit No.2 >

VSS

CIN

※　External Compone nts

* External Components

CIN : 4.7μF(ceramic)

CL : 10μF(ceramic)

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

VIN Lx

CE VOUT

< Circuit No.3 > < Circuit No.4 >

L1 L1

VSS

L2 L2

1μF

VIN Lx

CE VOUT

< Circuit No.5 >

L1 L1

ICEH

ICEL

VIN Lx

CE VOUT

VSS

1μF

Wave Form Measure Point

Rpulldown 200Ω

ILeakH

ILeakL

1μF

<CircuitNo.6>

1μF

VSS

VIN Lx

CE VOUT

VIN Lx

CE VOUT

VIN Lx

CE VOUT

ON resistance = (VIN-VLx)/100mA

Wave Form Measure Point

100mA

ILIM

< Circuit No.7 >

1μF

< Circuit No.9 >

CIN

VIN Lx

CE VOUT

VSS

L2 L2

VIN Lx

CE VOUT

VSS

Wave Form Measure Point

Ilat

Rpulldown 1Ω

<CircuitNo.8>

1uF

< Circuit No.10 >

CIN

※　External Compone nts

* External Components

L : 4.7uH(選別品)

CIN : 4.7μF(ceramic)

L: 4.7μH (Screening Parts)

CL : 10μF(ceramic)

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

L1L1

VIN Lx

CE VOUT

VSS

VIN Lx

CE VOUT

ILx

Wave Form Measure Point

14/21

)

XCL201/XCL202

■TYPICAL PERFORMANCE CHARACTERISTICS

(1) Efficiency vs. Output Current (2) Output Voltage vs. Output Current

100

Efficency:EFFI(%

XCL201B181BR/XCL202B181BR

XCL202(PWM/PFM)

VIN= 4.2V

3.6V

2.7V

XCL201(PWM)

XCL201B181BR/XCL202B181BR

2.1

VIN＝4.2V,3. 6V,2. 7V

2.0

(V)

1.9

OUT

XCL202

(PWM/PF M)

1.8

1.7

Output Voltage:V

1.6

XCL201

(PWM)

Series

0.01 0.1 1 10 100 1000

Output Current:I

OUT

(mA)



1.5

0.01 0.1 1 10 100 1000

Output Current:I

OUT

(mA)

(3) Ripple Voltage vs. Output Current (4) Oscillation Frequency vs. Ambient Temperature

100

VIN =4.2V

Ripple Voltage:Vr(mV)

0.01 0.1 1 10 100 1000

XCL201B181BR/XCL202B181BR

XCL202

(PWM/PFM)

3.6V

2.7V

Output Current:I

VIN =4.2V

(mA)

OUT

3.6V

XCL201

(PWM)

2.7V



1.5

1.4

1.3

1.2

1.1

1.0

0.9

Osc illation F requency : fosc(MHz)

0.8

-50 -25 0 25 50 75 100

XCL201B181BR/XCL202B181BR

VIN=3.6V

Ambient Temperature: Ta (℃)

(5) Supply Current vs. Ambient Temperature (6) Output Voltage vs. Ambient Temperature

XCL202B181BR

2.1

XCL201B181BR/XCL202B181BR

(μA)

4.0V

VIN=6.0V

Supply Current : I

2.0V

-50 -25 0 25 50 75 100

Ambient Temperature: Ta (℃)

2.0

(V)

1.9

OUT

VIN =3.6V

1.8

1.7

Output Voltage : V

1.6

1.5

-50 -25 0 25 50 75 100

Ambient Temperature: Ta (℃)

15/21

1ch

XCL201/XCL202 Series

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(7) UVLO Voltage vs. Ambient Temperature (8) CE "H" Voltage vs. Ambient Temperature

XCL201B181BR/XCL202B181BR

1.8

1.5

CE=VIN

1.2

0.9

0.6

0.3

UVLO Voltage : UVLO (V)

0.0

-50 -25 0 25 50 75 100

Ambient Temperatur e: Ta (℃)

1.0

0.9

0.8

(V)

0.7

CEH

0.6

0.5

0.4

0.3

0.2

CE "H" Voltage : V

0.1

0.0

-50 -25 0 25 50 75 100

(9) CE "L" Voltage vs. Ambient Temperature (10) "Pch / Nch" Driver on Resistance vs. Input Voltage 

XCL201B181BR/XCL202B181BR

1.0

0.9

0.8

(V)

0.7

CEL

0.6

VIN=5.0V

3.6V

0.5

0.4

0.3

CE "L" Voltage : V

0.2

0.1

0.0

-50 -25 0 25 50 75 100

2.4V

1.0

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

0.1

Lx SW ON Resistance:RLxH,RLxL (Ω)

0.0 0123456

Ambient Temperatur e: Ta (℃)

(11) Rise Wave Form

XCL201B331BR/XCL202B331BR

VIN=5.0V IOUT=1.0mA

XCL201B181BR/XCL202B181BR

VIN =5.0V

3.6V

2.4V

Ambient Temperature: Ta (℃)

XCL201B181BR/XCL202B181BR

Nc h on Res ist ance

Pch on Res ist ance

Input Voltage : V

(V)

2ch

VOUT

CE:0.0V⇒1.0V

1ch:1V/div2ch:1V/div

Time:100μs/div

16/21

)

1ch

2ch

1ch

XCL201/XCL202

Series

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(12) Soft-Start Time vs. Ambient Temperature (13) CL Discharge Resistance vs. Ambient Temperature

500

XCL201B121BR/XCL202B121BR

XCL201B331BR/XCL202B331BR

600

400

300

200

100

Soft Start Time : tss (μs)

-50 -25 0 25 50 75 100

Ambient Temperature: Ta (℃)

(14) Load Transient Response

MODE：PWM/PFM Automatic Switching Control

VIN=3.6V,VOUT=1.8V

XCL202B181BR

IOUT=1mA⇒100mA

VIN=5.0V IOUT=1.0mA

500

VIN =6.0V

2.0V

400

300

200

CL Discharge Res istance: (Ω

4.0V

100

-50 -25 0 25 50 75 100

Ambient Temperatur e: Ta (℃)

XCL202B181BR

VIN=3.6V,VOUT=1.8V

IOUT=1mA⇒300mA

1ch

VOUT

2ch

1ch:100mA/div2ch:50mV/div

time:200μs/div

VIN=3.6V,VOUT=1.8V

2ch

XCL202B181BR

IOUT=100mA⇒1mA

VOUT



VIN=3.6V,VOUT=1.8V

1ch

2ch

VOUT

time:200μs/div

XCL202B181BR

IOUT=300mA⇒1mA

VOUT

1ch:100mA/div2ch:50mV/div

time:200μs/div

1ch:100mA/div2ch:50mV/div

time:200μs/div

17/21

2ch

1ch

XCL201/XCL202 Series

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(14) Load Transient Response (Continued)

MODE：PWM Control

XCL201B181BR

VIN=3.6V,VOUT=1.8V

IOUT=1mA⇒100mA

1ch

VOUT

2ch

1ch:100mA/div2ch:50mV/div

time:200μs/div



VIN=3.6V,VOUT=1.8V

IOUT=1mA⇒300mA

VOUT

1ch:100mA/div2ch:50mV/div

time:200μs/div

VIN=3.6V,VOUT=1.8V

1ch

XCL201B181BR

VIN=3.6V,VOUT=1.8V

1ch

IOUT=100mA⇒1mA

XCL201B181BR

IOUT=300mA⇒1mA

18/21

2ch

VOUT

1ch:100mA/div2ch:50mV/div

time:200μs/div



2ch

VOUT

1ch:100mA/div2ch:50mV/div

time:200μs/div

■PACKAGING INFORMATION

●CL-2025 (unit:mm)

XCL201/XCL202

Series

■External Lead

●Reference Pattern Layout (unit:mm) ●Reference Metal Mask Design (unit:mm)



19/21

XCL201/XCL202 Series

■MARKING RULE

① represents products series

① ②

⑤④

 (G, I, J, O, Q, W excluded)

*No character inversion used.

③

CL-2025

MARK PRODUCT SERIES

F XCL201B*****-G

H XCL202B*****-G

② represents integer of output voltage and oscillation frequency

OUTPUT VOLTAGE (V)

0.x F

1.x H

2.x K

3.x L

4.x M

③ represents the decimal part of output voltage

OUTPUT VOLTAGE (V) MARK PRODUCT SERIES

X.0 0 XCL20***0***-G

X.05 A XCL20***A***-G

X.1 1 XCL20***1***-G

X.15 B XCL20***B***-G

X.2 2 XCL20***2***-G

X.25 C XCL20***C***-G

X.3 3 XCL20***3***-G

X.35 D XCL20***D***-G

X.4 4 XCL20***4***-G

X.45 E XCL20***E***-G

X.5 5 XCL20***5***-G

X.55 F XCL20***F***-G

X.6 6 XCL20***6***-G

X.65 H XCL20***H***-G

X.7 7 XCL20***7***-G

X.75 K XCL20***K***-G

X.8 8 XCL20***8***-G

X.85 L XCL20***L***-G

X.9 9 XCL20***9***-G

X.95 M XCL20***M***-G

Example (Mark ②, ③)

OSCILLATION

FREQUENCY

1.2MHz L 3 K C H L

④,⑤ represents production lot number 01〜09, 0A〜0Z, 11〜9Z, A1〜A9, AA〜AZ, B1〜ZZ in order.

XCL20**33***-G XCL20**2C***-G XCL20**1L***-G

② ③ ② ③ ② ③

MARK

OSCILLATION FREQUENCY=1.2MHz

(XCL20****1**-G)

MARK

20/21

XCL201/XCL202

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.

21/21

TOREX XCL201, XCL202 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual