XC9207_技术文档

XC9206/XC9207/XC9208Series

ETR0503_002

PWM, PWM / PFM Switchable Step-Down

DC / DC Converters With Driver Transistor Built-In

☆GO-Compatible

■GENERAL DESCRIPTION

The XC9206/XC9207/XC9208 series is a group of DC/DC converters with a built-in 0.4Ω P-channel driver transistor, offered

in a SOT-25 package. The ICs are designed to provide high efficiencies and a stable power supply with an output current of

500mA using only a coil, a diode and two ceramic capacitors connected externally.

Minimum operating voltage of the XC9206/9207 is 1.8V and 2.0V for XC9208. Output voltage is internally programmable in

a range from 0.9V to 4.0V in 100mV increments (accuracy: ±2.0%). Oscillation frequency is selectable from 300kHz, 600kHz

and 1.2MHz so that the frequency best suited to your particular application can be selected. Each series features different

operation modes: PWM control (XC9206 series), automatic PWM/PFM switching control (XC9207 series) and manual

PWM/PFM switching control (XC9208 series). The series gives fast transient response, low ripple and high efficiency over

the full range of load (from light load to high output current conditions). 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 U.V.L.O. (Under Voltage Lock Out) function, the internal P-channel driver transistor is forced OFF when input

voltage becomes 1.4V or lower.

■FEATURES

P-ch driver Tr. Built-in

Output Voltage Range

■APPLICATIONS

●Mobile phones

: ON resistance 0.4Ω

: 0.9V ~ 4.0V

(PDC, GSM, CDMA, IMT2000 etc.)

●PDAs, Portable communication modems

●Portable games

(100mV increments)

Fixed output voltage accuracy ±2%

Oscillation Frequency

: 300kHz, 600kHz, 1.2MHz

Fixed oscillation frequency

Accuracy ±15%

●Cameras, digital cameras

●Cordless phones

Stand-by function

: Istb = 1μA (MAX.)

: 600mA

●Note book computers

Current Limiter built-in

Input Voltage Range

: 1.8V ~ 6.0V(XC9206/XC9207)

2.0V ~ 6.0V (XC9208)

: 500mA

Output Current

Maximum Duty Ratio

: 100%

PWM/PFM Switching Control (XC9207 / XC9208)

Ceramic Capacitor Compatible

Soft start circuit built-in

Small Package

: SOT-25

■TYPICAL PERFORMANCE

CHARACTERISTICS

●Efficiency vs. Output Current

■TYPICAL APPLICATION CIRCUIT

XC9208A18C

VOUT=1.8V (Oscillation Frequency 1.2MHz)

CE/MODE

VOUT

CE/

CIN:4.7 F,CL:10 F, L:4.7 H(CDRH3D16),

μ

3

4

5

MODE

SD:CRS02, Topr=25

℃

100

90

80

70

60

50

40

30

20

10

0

PWM/PFM

VSS

Lx

2

1

Switching Control

VOUT

L

VIN

(500mA)

VIN=2.4V

3.6V

VIN

CL

(ceramic)

4.2V

CIN

(ceramic)

SD

PWM Control

L

:4.7μF (CDRH 3D16,SUMIDA)

0.1

1

10

100

1000

SD :CRS02 (SCHOTTKY DIODE,TOSHIBA)

CL :10μF (ceramic)

Output Current IOUT (mA)

CIN :4.7μF (ceramic)

1/16

XC9206/XC9207/XC9208 Series

■PIN ASSIGNMENT

■PIN CONFIGURATION

PIN NUMBER PIN NAME

FUNCTION

V_IN

CE/MODE

1

2

3

4

5

LX

VSS

Switching Output

Ground

VOUT

Output Voltage Sense

CE/MODE Chip Enable/Mode Switch

Power Input

VIN

Lx

V_SS

V_OUT

SOT-25

(TOP VIEW)

■PRODUCT CLASSIFICATION

●Ordering Information

XC9206①②③④⑤⑥: PWM Control

XC9207①②③④⑤⑥: PWM / PFM Automatic Switching Control

XC9208①②③④⑤⑥: PWM Control, PWM / PFM Automatic Switching Control Manually Selectable

DESIGNATOR

DESCRIPTION

SYMBOL

A

DESCRIPTION

: 600mA current limiter, Transistor built-in, output voltage

internally set (VOUT product), soft start internally set.

①

Type of DC/DC Converter

: 100mV increments

09~40

e.g. VOUT=1.5V→②=1, ③=5

②③

④

Output Voltage

: 1.85V VOUT →②=1, ③=L

2.85V VOUT →②=2, ③=L

09~40 & L

3

6

: 300kHz

: 600kHz

: 1.2MHz

Oscillation Frequency

C

⑤

⑥

Package

M

R

L

: SOT-25 (SOT-23-5)

: Embossed tape, standard feed

: Embossed tape, reverse feed

Device Orientation

* Output voltage 0.9V ~ 4.0V (100mV increments), 1.85V and 2.85V are standard products.

Output voltage other than these are available as semi-custom products.

2/16

XC9206/XC9207/XC9208

Series

■BLOCK DIAGRAM

Note: The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "L" level inside, and XC9206 series chooses

PWM control.

The signal from CE/MODE Control Logic to PWM/PFM Selector is being fixed to "H" level inside, and XC9207 series chooses

only PWM/PFM automatic switching control.

■ABSOLUTE MAXIMUM RATINGS

Ta=25℃

PARAMETER

VIN Pin Voltage

SYMBOL

VIN

RATINGS

- 0.3 ~ + 6.5

- 0.3 ~ VIN + 0.3

- 0.3 ~ + 6.5

- 0.3 ~ VIN + 0.3

± 1000

UNITS

V

VSS Pin Voltage

VSS

V

Lx Pin Voltage

VLx

V

VOUT Pin Voltage

VOUT

VCE

ILx

V

CE / MODE Pin Voltage

Lx Pin Current

V

mA

mW

℃

Power Dissipation

Pd

250

Operating Temperature Range

Storage Temperature Range

Topr

Tstg

- 40 ~ + 85

- 55 ~ + 125

℃

3/16

XC9206/XC9207/XC9208 Series

■ELECTRICAL CHARACTERISTICS

XC9206A18CMR, XC9207A18CMR, XC9208A18CMR

VOUT=1.8V, FOSC=1.2MHz, Ta=25℃

CIRCUIT

PARAMETER

Output Voltage

SYMBOL

VOUT

CONDITIONS

MIN. TYP. MAX. UNIT

When connected to ext. components

CE=VIN, IOUT=30mA

1.764 1.800 1.836

V

①

(XC9206, 9207)

(XC9208)

When connected to ext. components

1.8

2.0

-

6.0

Operating Voltage Range

Maximum Output Current

VIN

IOUTMAX

500

-

mA

CE=VIN, VOUT=0V,

Voltage which Lx pin voltage holding "L"

U.V.L.O. Voltage

VUVLO

1.00 1.40 1.78

V

②

level ^(*1)

CE=VIN, VOUT=fixed voltage x 0.9V

CE=VIN, VOUT=fixed voltage x 1.1V

CE=VSS, VOUT=fixed voltage x 1.1V

Supply Current 1

Supply Current 2

Stand-by Current

IDD1

IDD2

ISTB

-

255

98

0

413

158

1

μA

③

When connected to ext. components

CE=VIN, IOUT=30mA

Oscillation Frequency

FOSC

1.020 1.200 1.380 MHz

①

When connected to ext. components

(XC9207, XC9208 only), CE=VIN,

IOUT=1mA

PFM Pulse Width Rate

PFMDTY

24

30

36

0

%

①

Maximum Duty Cycle

Minimum Duty Cycle

MAXDTY CE=VIN, VOUT=0V

100

-

%

②

MINDTY

CE=VOUT=VIN

When connected to ext. components,

CE=VIN, IOUT=100mA

Efficiency ^(*2)

EFFI

-

86

%

①

Lx SW ON Resistance

Current Limit

RLx

ILIM

CE=VIN, VOUT=0V, ILx=400mA ^(*3)

-

0.4

0.9

-

Ω

④

VIN=CE=5.0V, VOUT=0V

600

mA

VOUT=0V, When CE

voltage is applied Lx

determine "H"

(XC9206, 9207)

1.2

-

VIN

CE "H" Voltage

VCEH

V

⑤

(XC9208) 0.9

VOUT=0V, When CE voltage is applied Lx

determine "L"

CE "L" Voltage

PWM "H" Voltage

PWM "L" Voltage

VCEL

VSS

VIN-0.3

-

0.3

-

V

⑤

①

When connected to ext. components

(XC9208 only), IOUT=1mA ^(*4)

VPWMH

VPWML

When connected to ext. components

(XC9208 only), IOUT=1mA ^(*4)

VIN-1.0

CE "H" Current

CE "L" Current

ICEH

ICEL

CE=VIN=5.5V, VOUT=0V

-0.1

-

0.1

μA

⑤

CE=0V, VIN=5.5V, VOUT=0V

When connected to ext. components

CE=0V → VIN, IOUT=1mA

Soft-Start Time

TSS

0.8

-

6.0

ms

①

When connected to ext. components

VIN=CE=5.0V, short VOUT by 1Ω

resistance ^(*5)

Latch Time

Tlat

-

12.0

ms

⑥

Test condition: Unless otherwise stated, VIN = 3.6V

NOTE:

*1: Including hysteresis operating voltage range.

*2: EFFI = [ (output voltage x output current) / (input voltage x input current) ] x 100

*3: On resistance = VLx (measurement voltage) / 0.4

*4: The CE/MODE pin of the XC9208A series works also as an external PWM control and PWM/PFM control switching pin. When the

IC is in the operation, control is switched to the PWM mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3

V, and to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0 V and

equal to or greater than VCEH.

*5: Time until it short-circuits VOUT with GND through 1Ωof resistance from a state of operation and is set to VOUT=0V from current limit

pulse generating.

4/16

XC9206/XC9207/XC9208

Series

■ELECTRICAL CHARACTERISTICS (Continued)

XC9206A25CMR, XC9207A25CMR, XC9208A25CMR

VOUT=2.5V, FOSC=1.2MHz, Ta=25℃

PARAMETER

Output Voltage

SYMBOL

VOUT

CONDITIONS

MIN. TYP. MAX. UNIT CIRCUIT

When connected to ext. components

CE=VIN, IOUT=30mA

2.450 2.500 2.550

V

①

(XC9206, 9207) 1.8

-

6.0

-

Operating Voltage Range

Maximum Output Current

VIN

V

①

(XC9208)

2.0

IOUTMAX

When connected to ext. components

500

mA

CE=VIN, VOUT=0V,

U.V.L.O. Voltage

VUVLO

Voltage which Lx pin voltage holding "L"

1.00 1.40 1.78

V

②

level ^(*1)

Supply Current 1

Supply Current 2

Stand-by Current

IDD1

IDD2

ISTB

CE=VIN, VOUT=fixed voltage x 0.9V

CE=VIN, VOUT=fixed voltage x 1.1V

CE=VSS, VOUT=fixed voltage x 1.1V

-

255

98

0

413

158

1

μA

③

When connected to ext. components

CE=VIN, IOUT=30mA

Oscillation Frequency

FOSC

1.020 1.200 1.380 MHz

①

When connected to ext. components

PFMDTY (XC9207, XC9208 only), CE=VIN,

IOUT=1mA

PFM Pulse Width Rate

24

30

36

0

%

①

Maximum Duty Cycle

Minimum Duty Cycle

MAXDTY CE=VIN, VOUT=0V

100

-

%

②

MINDTY

EFFI

CE=VOUT=VIN

When connected to ext. components,

CE=VIN, IOUT=100mA

CE=VIN, VOUT=0V, ILx=400mA ^(*3)

Efficiency ^(*2)

-

91

%

①

Lx SW ON Resistance

Current Limit

RLx

ILIM

-

0.4

600

-

0.9

-

Ω

④

VIN=CE=5.0V, VOUT=0V

-

mA

VOUT=0V, When CE

voltage is applied Lx

determine "H"

(XC9206, 9207) 1.2

VIN

CE "H" Voltage

VCEH

V

⑤

(XC9208)

0.9

-

VIN

0.3

VOUT=0V, When CE voltage is applied Lx

determine "L"

CE "L" Voltage

PWM "H" Voltage

PWM "L" Voltage

VCEL

VSS

V

⑤

①

When connected to ext. components

(XC9208 only), IOUT=1mA ^(*4)

VPWMH

VPWML

VIN-0.3

-

When connected to ext. components

(XC9208 only), IOUT=1mA ^(*4)

VIN-1.0

CE "H" Current

CE "L" Current

ICEH

ICEL

CE=VIN=5.5V, VOUT=0V

-0.1

-

0.1

μA

⑤

CE=0V, VIN=5.5V, VOUT=0V

When connected to ext. components

CE=0V →VIN, IOUT=1mA

Soft-Start Time

TSS

0.8

-

6.0

ms

①

When connected to ext. components

VIN=CE=5.0V, short VOUT by 1Ω

resistance ^(*5)

Latch Time

Tlat

-

12.0

ms

⑥

Test condition : Unless otherwise stated, VIN = 3.6V

NOTE:

*1 : Including hysteresis operating voltage range.

*2 : EFFI = [ (output voltage x output current) / (input voltage x input current) ] x 100

*3 : On resistance = VLX (measurement voltage) / 0.4

*4 : The CE/MODE pin of the XC9208A series works also as an external PWM control and PWM/PFM control switching pin. When the

IC is in the operation, control is switched to the PWM mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3

V, and to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0 V and

equal to or greater than VCEH.

*5 : Time until it short-circuits VOUT with GND through 1Ω of resistance from a state of operation and is set to VOUT=0V from current

limit pulse generating.

5/16

XC9206/XC9207/XC9208 Series

■ELECTRICAL CHARACTERISTICS (Continued)

XC9206A33CMR, XC9207A33CMR, XC9208A33CMR

VOUT=3.3V,FOSC=1.2MHz, Ta=25℃

PARAMETER

Output Voltage

SYMBOL

VOUT

CONDITIONS

MIN. TYP. MAX. UNIT CIRCUIT

When connected to ext. components

CE=VIN, IOUT=30mA

3.234 3.300 3.366

V

①

(XC9206, 9207) 1.8

(XC9208) 2.0

When connected to ext. components 500

CE=VIN, VOUT=0V,

-

6.0

-

Operating Voltage Range

Maximum Output Current

VIN

V

①

IOUTMAX

mA

U.V.L.O. Voltage

VUVLO

Voltage which Lx pin voltage holding "L" 1.00 1.40 1.78

V

②

level ^(*1)

Supply Current 1

Supply Current 2

Stand-by Current

IDD1

IDD2

Istb

CE=VIN, VOUT=fixed voltage x 0.9V

CE=VIN, VOUT=fixed voltage x 1.1V

CE=VSS, VOUT=fixed voltage x 1.1V

-

370

120

0

585

180

1

μA

③

When connected to ext. components

CE=VIN, IOUT=30mA

Oscillation Frequency

FOSC

1.020 1.200 1.380 MHz

①

When connected to ext. components

PFMDTY (XC9207, XC9208 only),

PFM Pulse Width Rate

26

32

38

0

%

①

CE=VIN, IOUT=1mA

Maximum Duty Cycle

Minimum Duty Cycle

MAXDTY CE=VIN, VOUT=0V

MINDTY CE=VOUT=VIN

100

-

%

②

When connected to ext. components,

CE=VIN, IOUT=100mA

CE=VIN, VOUT=0V, ILx=400mA ^(*3)

Efficiency ^(*2)

EFFI

-

92

%

①

Lx SW ON Resistance

Current Limit

RLx

ILIM

-

0.4

600

-

0.9

-

Ω

④

VIN=CE=5.0V, VOUT=0V

-

mA

VOUT=0V, When CE

voltage is applied Lx

determine "H"

(XC9206, 9207) 1.2

VIN

CE "H" Voltage

CE "L" Voltage

VCEH

VCEL

V

⑤

(XC9208) 0.9

-

VIN

0.3

VOUT=0V, When CE voltage is applied

Lx determine "L"

VSS

-

When connected to ext. components

(XC9208 only), IOUT=1mA ^(*4)

PWM "H" Voltage

PWM "L" Voltage

VPWMH

VPWML

VIN-0.3

-

V

①

When connected to ext. components

(XC9208 only), IOUT=1mA ^(*4)

VIN-1.0

CE "H" Current

CE "L" Current

ICEH

ICEL

CE=VIN=5.5V, VOUT=0V

-0.1

-

0.1

μA

⑤

CE=0V, VIN=5.5V, VOUT=0V

When connected to ext. components

CE=0V → VIN, IOUT=1mA

Soft Start Time

TSS

0.8

-

6.0

ms

①

When connected to ext. components

VIN=CE=5.0V, short VOUT by 1Ω

resistance ^(*5)

Latch Time

Tlat

-

12.0

ms

⑥

Test condition: Unless otherwise stated, VIN = 5.0V

NOTE:

*1: Including hysteresis operating voltage range.

*2: EFFI = [ (output voltage x output current) / (input voltage x input current) ] x 100

*3: On resistance = VLX (measurement voltage) / 0.4

*4: The CE/MODE pin of the XC9208A series works also as an external PWM control and PWM/PFM control switching pin. When the

IC is in the operation, control is switched to the PWM mode when the CE/MODE pin voltage is equal to or greater than VIN minus 0.3

V, and to the automatic PWM/PFM switching mode when the CE/MODE pin voltage is equal to or lower than VIN minus 1.0 V and

equal to or greater than VCEH.

*5: Time until it short-circuits VOUT with GND through 1Ω of resistance from a state of operation and is set to VOUT=0V from current limit

pulse generating.

6/16

XC9206/XC9207/XC9208

Series

■TYPICAL APPLICATION CIRCUIT

●FOSC=1.2MHz

: 4.7μH (CDRH3D16,

SUMIDA)

SD : CRS02 (TOSHIBA)

CIN : 4.7μF (Ceramic)

CL : 10μF (Ceramic)

●FOSC=600kHz

CE/MODE

VOUT

CE/

3

L

: 10μH

(CDRH4D18C,

SUMIDA)

4

MODE

VSS

Lx

SD : CRS02 (TOSHIBA)

CIN : 4.7μF (Ceramic)

2

1

VOUT

(500mA)

L

VIN

CL : 10μF

(Ceramic)

VIN

5

CL

(ceramic)

CIN

(ceramic)

SD

●FOSC=300kHz

L

: 22μH (CDRH4D18,

*SD : Schottky diode

SUMIDA)

SD : CRS02 (TOSHIBA)

CIN : 4.7μF (Ceramic)

CL : 10μF (Ceramic)

* XC9206/9207/9208 series wire connection

■OPERATIONAL EXPLANATION

Each unit of the XC9206/9207/9208 series consists of a reference voltage source, ramp wave circuit, error amplifier, PWM

comparator, phase compensation circuit, output voltage adjustment resistors, driver transistor, current limiter circuit, U.V.L.O.

circuit and others. The series ICs compare, using the error amplifier, the voltage of the internal voltage reference source with

the feedback voltage from the VOUT pin through resistors R1 and R2. Phase 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.

< Reference Voltage Source >

The reference voltage source provides the reference voltage to ensure stable output voltage of the ICs.

< Ramp Wave Circuit >

The ramp wave circuit determines switching frequency. The frequency is fixed internally and can be selected from 300kHz,

600 kHz and 1.2 MHz. 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 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.

The current limiter circuit of the XC9206/9207/9208 series monitors the current flowing through the P-channel MOS driver

transistor connected to the Lx pin, and features a combination of the constant-current type current limit mode and the operation

suspension mode.

①When the driver current is greater than a specific level, the constant-current type current limit function operates to turn off the

pulses from the Lx pin at any given timing.

②When the driver transistor is turned off, the limiter circuit is then released from the current limit detection state.

③At the next pulse, the driver transistor is turned on. However, the transistor is immediately turned off in the case of an over

current state.

④When 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

several msec 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 VIN pin. The suspension mode does not mean a

complete shutdown, but a state in which pulse output is suspended; therefore, the internal circuitry remains in operation. The

constant-current type current limit of the XC9206A/9207A/9208A series can be set at 600 mA.

Limit < #ms

Limit > #ms

Limit< #mS

Limit> #mS

Current Limit LEVEL

IOUT

0mA

VSS

VOUT

LX

CE/MODE

Restart

VIN

7/16

XC9206/XC9207/XC9208 Series

■OPERATIONAL EXPLANATION (Continued)

< U.V.L.O. Circuit>

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

output caused by unstable operation of the internal circuitry. When the VIN pin voltage becomes 1.8 V or higher, switching

operation takes place. By releasing the U.V.L.O. 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 U.V.L.O. operating

voltage. The U.V.L.O. circuit does not cause a complete shutdown of the IC, but causes pulse output to be suspended;

therefore, the internal circuitry remains in operation.

< Function of CE/MODE pin >

The XC9206/9207/9208 series will enter into shut down state by inputting a low level signal to the CE/MODE pin. During a

shut down state, the current consumption of the IC becomes 0μA (TYP.), with a state of high impedance at the Lx pin and

VOUT pin. The IC starts its operation by inputting a high level signal to the CE/MODE pin. The input of the CE/MODE pin is

a CMOS input and the sink current is 0μA (TYP.).

●XC9206A / 07A series - Examples of how to use CE/MODE pin

SW_CE

ON

STATUS

Chip Disable

A

B

PWM control (XC9206),

PWM/PFM automatic switching control (XC9207

PWM control (XC9206),

OFF

ON

)

PWM/PFM automatic switching control (XC9207)

OFF

Chip Disable

(A)

(B)

●XC9208A series - Examples of how to use CE/MODE pin

SW_CE SW_PMW/PFM

STATUS

ON

*

Synchronous PWM control

Non-synchronous PWM/PFM

automatic switching control

OFF

ON

A

OFF

ON

OFF

*

Chip Disable

Non-synchronous PWM/PFM

automatic switching control

(A)

(B)

OFF

ON

OFF

B

Synchronous PWM control

Intermediate voltage can be generated by RM1 and RM2. Please set the value of each R1, R2, RM1, RM2 at around 100kΩ.

For switches, CPU open-drain I/O port and transistor can be used.

< PWM / PFM >

XC9207/9208 series features PWM/PFM automatic switching control.

With the automatic PWM/PFM switching control function, the series ICs are automatically switched from PWM control to

PFM control mode under light load conditions. If during light load conditions the coil current becomes discontinuous and

on-time rate falls lower than PFM duty, the PFM circuit operates to output a pulse with a fixed on-time rate from the Lx pin.

During PFM operation with this fixed on-time rate, pulses are generated at different frequencies according to conditions of

the moment. This causes a reduction in the number of switching operations per unit of time, resulting in efficiency

improvement under light load conditions. However, since pulse output frequency is not constant, consideration should be

given if a noise filter or the like is needed. Necessary conditions for switching to PFM operation depend on input voltage,

load current, coil value and other factors.

8/16

XC9206/XC9207/XC9208

Series

■NOTES ON USE

●Application Information

1. The XC9206/9207/9208 series are designed for use with an output ceramic capacitor. If, however, the potential

difference between input and output is too large, 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. When the difference between VIN and VOUT is large and the load current is light, very narrow pulses will be outputted,

and there is the possibility that some cycles may be skipped completely.

●Oscillation Wave Form (FOSC=1.2MHz)

① VIN = 5.5V, VOUT=1.8V, IOUT=10mA

CH1 : Lx

L

: 4.7μH (CDRH3D16,

SUMIDA)

SD : CRS02 (TOSHIBA)

CH2 : VOUT

CIN : 4.7μF

CL

: 10μF

(Ceramic)

AC-COUPLED

4. When the difference between VIN and VOUT 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: in this case, the Lx pin may not go low at all.

●Oscillation Wave Form (FOSC=1.2MHz)

② VIN = 2.0V, VOUT=1.8V, IOUT=60mA

CH1 : Lx

L

: 4.7μH (CDRH3D16,

SUMIDA)

SD : CRS02 (TOSHIBA)

CH2 : VOUT

CIN : 4.7μF

CL

: 10μF

(Ceramic)

AC-COUPLED

5. 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 operating, 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 = (VIN - VOUT) x On Duty / (2 x L x FOSC) + IOUT

OnDuty: OnDuty ratio of Pch Driver Transistor

L

: Coil Inductance Value

FOSC : Oscillation Frequency

6. When the peak current which exceeds limit current flows within the specified time, the built-in P-ch driver transistor is

turned 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 coil or the schottky diode.

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

9/16

XC9206/XC9207/XC9208 Series

■NOTES ON USE (Continued)

●Application Information (Continued)

8. 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 capacitors are placed as close to the chip as possible.

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

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

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

may increase. When the series' duty cycle is digitally signalized, the linear duty cycle and the digitally signalized duty

cycle cannot carry out completely the same change, which means that the duty cycle does not change linearly. The

output is stabilized by applying the phase compensation and adjusting the duty cycle, even when the duty cycle loses the

linear change in the whole circuit. When the state where the output was stabilized is continued by applying phase

compensation to duty cycle which lost linearity, ripple voltage does not increase more than it. The ripple voltage may

increase to about several 10mV according to operating conditions. It is possible, by increasing the capacitance values,

to reduce the ripple voltage. The operating conditions are greatly influenced by the dropout voltage, the load current, the

delay-time, or the external components, such as the coil inductance, and the capacitance values. Verification with actual

parts should be done.

●The Increase of Ripple Voltage (1.2MHz)

① VIN=4.2V, VOUT=1.8V, IOUT=180mA

② VIN=4.2V, VOUT=1.8V, IOUT=60mA

CH1: Lx

CH2: VOUT

AC-COUPLED

③ VIN=3.6V, VOUT=1.8V, IOUT=30mA

L

: 4.7μH (CDRH3D16,

CH1: Lx

SUMIDA)

SD : CRS02 (TOSHIBA)

CH2: VOUT

CIN : 4.7μF

CL

: 10μF

(Ceramic)

AC-COUPLED

10/16

XC9206/XC9207/XC9208

Series

■NOTES ON USE (Continued)

●Instructions on Pattern Layout

1. In order to stabilize VDD's 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, and connect it to GND with the

shortest possible PCB traces.

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.

5. Please connect SD anode directly to the by-pass capacitor C_IN(-) in order to minimize SD noise affect on to

the V_SSpin of the IC. Also, take distance between the V_SSpin and the SD anode for having large impedance

as possible. We recommend that a ferrite bead mount pattern be arranged for the case that the SD noise

can not be reduced by using the pattern layout as shown below.

6. Please do not make the traces under the IC to carry switching main current. It may cause a malfunction of

the IC.

VOUT

L

VSS

XC9206/07/08

R.1.1

SD

SOT-25

CE

VIN

Ferrite Bead

Figure XC9206/07/08Series Pattern Layout

11/16

XC9206/XC9207/XC9208 Series

■TEST CIRCUITS

Circuit ①

Circuit ②

CE

/MODE

VOUT

4

3

2

1

VOUT

CE

/MODE

4

5

3

2

1

VSS

Lx

VSS

Lx

L

VIN

5

VI

SD

V

CL

CIN

RL

200

Ω

1

F

μ

Circuit ③

Circuit ④

VOUT

CE

/MODE

VOUT

CE

4

3

2

4

3

2

1

/MODE

VSS

Lx

VSS

Lx

A

VIN

5

1

5

V

L

1μF

1

F

μ

Circuit ⑤

Circuit ⑥

H

CE

/MODE

CE

/MODE

VOUT

4

3

2

1

4

5

3

2

1

A

L

VSS

Lx

VSS

Lx

L

VI

5

VIN

SD

V

1k

Ω

CL

CIN

1

F

μ

1

Ω

1.2MHz

600kHz

300kHz

CIN

CL

L

4.7μF (ceramic)

10μF (ceramic)

4.7μH

4.7μF (ceramic)

10μF (ceramic)

10μH

4.7μF (ceramic)

10μF (ceramic)

22μH

SD

Schottky Diode

12/16

XC9206/XC9207/XC9208

Series

■TYPICAL PERFORMANCE CHARACTERISTICS

(1) Output Voltage vs. Output Current

XC9208A18C

VOUT=1.8V (Oscillation Frequency1.2MHz)

XC9208A186

VOUT=1.8V (Oscillation Frequency 600kHz)

CIN:4.7 F,CL:10 F, L:4.7 H(CDRH3D16),

CIN:4.7 F,CL:10 F, L:10 H(CDRH4D18C),

μ μ μ

μ

SD:CRS02, Topr=25

℃

2

1.9

1.8

1.7

1.6

1.5

2

1.9

1.8

1.7

1.6

1.5

PWM/PFM

3.6V, 4.2V

VIN=2.4V

Switching Control

PWM

PWM Control

3.6V

4.2V

Control

0.1

1

10

100

1000

0.1

1

10

100

1000

Output Current: I_OUT(mA)

Output Current IOUT (mA)

Output Current: I_OUT(mA)

Output Current IOUT (mA)

(2) Efficiency vs. Output Current

XC9208A183

VOUT=1.8V (Oscillation Frequency 300kHz)

CIN:4.7 F,CL:10 F, L:22 H(CDRH4D28C),

μ

SD:CRS02, Topr=25

℃

2

1.9

1.8

1.7

1.6

1.5

PWM/PFM

3.6V, 4.2V

VIN=2.4V

Switching Control

PWM Control

0.1

1

10

100

1000

Output Current: I_OUT(mA)

Output Current IOUT (mA)

Output Current: I_OUT(mA)

13/16

XC9206/XC9207/XC9208 Series

■TYPICAL PERFORMANCE CHARACTERISTICS (Continued)

(3) Ripple Voltage vs. Output Current

XC9208A18C

XC9208A186

VOUT=1.8V (Oscillation Frequency 1.2MHz)

VOUT=1.8V (Oscillation Frequency 600kHz)

CIN:4.7 F,CL:10 F, L:4.7 H(CDRH3D16),

μ

CIN:4.7 F,CL:10 F, L:10 H(CDRH4D18C),

μ

SD:CRS02, Topr=25

℃

SD:CRS02, Topr=25

℃

100

80

60

40

20

0

100

80

60

40

20

0

PWM Control

4.2V

3.6V

PWM/PFM Switching

Control

PWM/PFM Switching Control

4.2V

3.6V

VIN=2.4V

0.1

1

10

100

1000

0.1

1

10

100

1000

Output Current IOUT (mA)

Output Current: I_OUT(mA)

Output Current IOUT (mA)

XC9208A183

VOUT=1.8V (Oscillation Frequency 300kHz)

CIN:4.7 F,CL:10 F, L:22 H(CDRH3D28C),

μ

SD:CRS02, Topr=25

℃

100

80

60

40

20

0

PWM Control

PWM/PFM Switching

Control

3.6V

4.2V

VIN=2.4V

0.1

1

10

100

1000

Output Current IOUT (mA)

Output Current: I_OUT(mA)

■PACKAGING INFORMATION

●SOT-25

14/16

XC9206/XC9207/XC9208

Series

■MARKING RULE

●SOT-25

① Represents product name and type of DC/DC converters

5

4

MARK

PRODUCT SERIES

XC9206AxxxMx

XC9207AxxxMx

XC9208AxxxMx

①

②

③

④

6

7

8

1

2

3

* Character inversion is used.

SOT-25

(TOP VIEW)

② Represents integer of output voltage and oscillation frequency

MARK

OUTPUT VOLTAGE

(V)

FOSC=300kHz

FOSC=600kHz

FOSC=1.2MHz

XC920xx②x3Mx

XC920xx②x6Mx

XC920xx②xCMx

0

1

2

3

4

0

1

2

3

4

A

B

C

D

E

0.x

1.x

2.x

3.x

4.x

③ Represents decimal number of output voltage and oscillation frequency

MARK

OUTPUT VOLTAGE

(V)

FOSC=300kHz

FOSC=600kHz

FOSC=1.2MHz

XC920xxx③3Mx

XC920xxx③6Mx

XC920xxx③CMx

0

1

2

3

4

5

6

7

8

Z

9

A

B

C

D

E

F

A

B

C

D

E

F

x. 0

x. 1

x. 2

x. 3

x. 4

x. 5

x. 6

x. 7

x. 8

x. 85

x. 9

H

K

L

H

K

L

Y

M

Y

M

* Output voltage 0.9V ~ 4.0V (100mV increments), 1.85V and 2.85V are standard products.

Output voltages other than these are available as semi-custom products.

②③ example :

MARK

OSCILLATION

VOUT=3.3V

VOUT=5.0V

VOUT=1.85V

FREQUENCY

②

③

3

②

③

0

②

③

Z

300kHz

600kHz

1.2MHz

3

5

F

1

B

D

A

Y

D

Y

④ Represents production lot number

0 to 9, A to Z repeated (G, I, J, O, Q, W excepted)

15/16

XC9206/XC9207/XC9208 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 catalog 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 catalog.

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

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

4. The products in this catalog 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 catalog 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.

16/16


型号：	XC9207
厂家：	Torex Semiconductor
描述：	PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In PWM ， PWM / PFM切换降压型DC / DC与驱动晶体管转换器内置晶体转换器晶体管驱动
文件：	总16页 (文件大小：475K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

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