XC9206A2LCMR_技术文档

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

September 17, 2003 Ver. 2

! P-Channel Driver Transistor Built-In

" APPLICATIONS

! Input Voltage Range

: 1.8V ~ 6.0V (XC9206/XC9207)

# Mobile phones (PDC, GSM, CDMA, IMT2000 etc.)

# PDA, Portable communication modem

# Portable game

: 2.0V ~ 6.0V (XC9208)

: 0.9V ~ 4.0V

! Output Voltage Range

! Oscillation Frequency

! Output Current

: 300kHz, 600kHz, 1.2MHz

: 500mA

# Camera, Digital camera, Camcorder

# Cordless phone

! Maximum Duty Ratio

! Small Package

: 100%

# Note book computer

: SOT-25

! PWM/PFM Switching Control (XC9207 / XC9208)

! Ceramic Capacitor Compatible

" GENERAL DESCRIPTION

" FEATURES

The XC9206/9207/9208 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 increments of 100mV (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.

P ch driver Tr. Built-in

ON resistance 0.4Ω

Output Voltage Range

Oscillation Frequency

0.9V ~ 4.0V (100mV steps)

Fixed output voltage accuracy ±2%

300kHz, 600kHz, 1.2MHz

Fixed oscillation frequency

accuracy ±15%

Stand-by function

Istb = 1µA (MAX.)

Current Limiter Circuit built-in 600mA

Small Package

SOT-25

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.

Soft start circuit built-in

" TYPICAL APPLICATION CIRCUIT

" TYPICAL PERFORMANCE CHARACTERISTICS

CE/MODE

XC9208A18C

VOUT=1.8V (Oscillation Frequency 1.2MHz)

VOUT

MODE

CE/

3

4

5

CIN:4.7µF,CL:10µF, L:4.7µH(CDRH3D16),

VSS

Lx

SD:CRS02, Topr=25^OC

2

1

VOUT

100

90

80

70

60

50

40

30

20

10

0

L

PWM/PFM

Switching Control

VIN

(500mA)

VIN

VIN=2.4V

CL

(ceramic)

CIN

(ceramic)

SD

3.6V

4.2V

PWM

Control

0.1

1

10

100

1000

Output Current IOUT (mA)

Semiconductor Ltd.

Data Sheet

1

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" PIN CONFIGURATION

" PIN ASSIGNMENT

VIN

5

CE/MODE

4

PIN NUMBER

PIN NAME

FUNCTIONS

1

2

3

4

5

LX

VSS

Switching Output

Ground

VOUT

CE/MODE

VIN

Output Voltage Sense

Chip Enable/Mode Switch

Power Input

1

2

3

Lx

VSS

VOUT

SOT-25 (TOP VIEW)

" PRODUCT CLASSIFICATION

# Ordering Information

XC9206 123456

XC9207 123456

XC9208 123456

: PWM Control

: PWM / PFM Automatic Switching Control

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

SYMBOL

DESCRIPTION

Transistor built-in, output voltage internally set (VOUT product), soft start internally set.

A : Current Limiter 600mA

1

Denotes output voltage :

ex. ) 1.5V Output ꢀ 2= 1, 3= 5

1.85V Output ꢀ 2= 1, 3= L

2.85V Output ꢀ 2= 2, 3= L

Denotes oscillation frequency :

3 : 300kHz

2, 3

4

6 : 600kHz

C : 1.2MHz

Denotes package types :

M : SOT-25

5

6

Denotes device orientation :

R : Embossed Tape : Standard Feed

L : Embossed Tape : Reverse Feed

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

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

" PACKAGING INFORMATION

$ SOT-25

Semiconductor Ltd.

Data Sheet

2

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" MARKING RULE

$ SOT-25

1Represents the product name and the type of DC/DC converters

5

4

DESIGNATOR

PRODUCT NAME

XC9206A x x x M x

XC9207A x x x M x

XC9208A x x x M x

6

7

1234

8

* Character inversion is used.

1

2

3

SOT-25

(TOP VIEW)

2Represents the integer of the output voltage and the oscillation frequency

DESIGNATOR

OUTPUT VOLTAGE

FOSC=300kHz

FOSC=600kHz

FOSC=1.2MHz

(XC920 x x 2x 3M x)

(XC920 x x 2x 6M x)

(XC920 x x 2x CM x)

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

3Represents the decimal number of output voltage and the oscillation frequency

DESIGNATOR

OUTPUT VOLTAGE

FOSC=300kHz

FOSC=600kHz

FOSC=1.2MHz

(XC920 x x x 33M x)

(XC920 x x x 36M x)

(XC920 x x x 3CM x)

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 steps), 1.85V and 2.85V are standard products.

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

4Represents the production lot number.

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

Semiconductor Ltd.

Data Sheet

3

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" BLOCK DIAGRAM

Phase

Compensation

VOUT

Pch

Driver

Tr.

PWM

Comparator

R1

R2

Buffer

Driver

Logic

VIN

LX

Error Amp.

Current

Limit & Feedback

Vref with

Soft Start,

CE

PWM/PFM

Selector

Ramp Wave

Generator,

OSC

U.V.L.O Comp.

CE/MODE

Control

Logic

U.V.L.O

CE/MODE

VSS

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^OC

PARAMETER

SYMBOL

RATINGS

UNITS

VIN Pin Voltage

Lx Pin Voltage

VIN

VLx

- 0.3 ~ + 6.5

V

- 0.3 ~ V_IN+ 0.3

VOUT Pin Voltage

VOUT

VCE

- 0.3 ~ + 6.5

V

- 0.3 ~ V_IN+ 0.3

CE / MODE Pin Voltage

± 1000

250

Lx Pin Current

ILx

Pd

mA

mW

^OC

Continuous Power Dissipation

Operating Temperature Range

Storage Temperature Range

Topr

Tstg

- 40 ~ + 85

- 55 ~ + 125

^OC

Semiconductor Ltd.

Data Sheet

4

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" ELECTRICAL CHARACTERISTICS

XC9206A18CMR, XC9207A18CMR, XC9208A18CMR

VOUT=1.8V, FOSC=1.2MHz, Ta=25^OC

MIN TYP MAX

PARAMETER

SYMBOL

CONDITIONS

When connected to ext. components

CE=VIN, IOUT=30mA

UNIT CIRCUIT

Output Voltage

VOUT

1.764 1.800 1.836

V

1

(XC9206, 9207)

(XC9208)

1.8

2.0

500

-

6.0

-

Operating Voltage Range

VIN

1

2

Maximum Output Current

U.V.L.O Voltage

IOUTMAX When connected to ext. components

mA

V

CE=VIN, VOUT=0V,

VUVLO

1.00

1.40

1.78

Voltage which Lx pin voltage holding "L" level (*1)

Supply Current 1

Supply Current 2

IDD1

IDD2

µA 3

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

3

µA

Stand-by Current

Istb

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

2

1

4

Maximum Duty Cycle

Minimum Duty Cycle

Efficiency (*2)

MAXDTY CE=VIN, VOUT=0V

MINDTY CE=VOUT=VIN

100

-

%

-

EFFI

RLx

When connected to ext. components, CE=VIN, IOUT=100mA

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

86

0.4

600

-

%

Lx SW ON Resistance

Current Limit

-

0.9

-

Ω

ILIM

VIN=CE=5.0V, VOUT=0V

-

mA

VOUT=0V, When CE voltage is

applied Lx determine "H"

(XC9206, XC9207)

(XC9208)

1.2

0.9

VSS

VIN

0.3

CE "H" Voltage

VCEH

V

5

-

CE "L" Voltage

VCEL

VOUT=0V, When CE voltage is applied Lx determine "L"

-

V 5

When connected to ext. components (XC9208 only)

IOUT=1mA (*4)

PWM "H" Voltage

VPWMH

VIN-0.3

-

V

1

When connected to ext. components (XC9208 only)

IOUT=1mA (*4)

PWM "L" Voltage

VPWML

VIN-1.0

V

5

µA

CE "H" Current

CE "L" Current

ICEH

ICEL

CE=VIN=5.5V, VOUT=0V

-0.1

-

0.1

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

When connected to ext. components

CE=0V ꢀVIN, IOUT=1mA

Soft start time

Latch Time

TSS

Tlat

0.8

-

6.0

ms

1

6

When connected to ext. components

12.0

VIN=CE=5.0V, short VOUT by 1Ω resistance (*5)

Test condition : Unless otherwise stated, VIN = 3.6V

*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

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.

*4

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

generating.

*5

Semiconductor Ltd.

Data Sheet

5

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" ELECTRICAL CHARACTERISTICS

XC9206A25CMR, XC9207A25CMR, XC9208A25CMR

VOUT=2.5V, FOSC=1.2MHz, Ta=25^OC

MIN TYP MAX

PARAMETER

SYMBOL

CONDITIONS

When connected to ext. components

CE=VIN, IOUT=30mA

UNIT CIRCUIT

Output Voltage

VOUT

2.450 2.500 2.550

V

1

(XC9206, 9207)

(XC9208)

1.8

2.0

500

-

6.0

-

Operating Voltage Range

VIN

1

2

Maximum Output Current

U.V.L.O Voltage

IOUTMAX When connected to ext. components

mA

V

CE=VIN, VOUT=0V,

VUVLO

1.00

1.40

1.78

Voltage which Lx pin voltage holding "L" level (*1)

Supply Current 1

Supply Current 2

IDD1

IDD2

µA 3

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

3

µA

Stand-by Current

Istb

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

2

1

4

Maximum Duty Cycle

Minimum Duty Cycle

Efficiency (*2)

MAXDTY CE=VIN, VOUT=0V

MINDTY CE=VOUT=VIN

100

-

%

-

EFFI

RLx

When connected to ext. components, CE=VIN, IOUT=100mA

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

91

0.4

600

-

%

Lx SW ON Resistance

Current Limit

-

0.9

-

Ω

ILIM

VIN=CE=5.0V, VOUT=0V

-

mA

VOUT=0V, When CE voltage is

applied Lx determine "H"

(XC9206, XC9207)

(XC9208)

1.2

0.9

VSS

VIN

0.3

CE "H" Voltage

VCEH

V

5

-

CE "L" Voltage

VCEL

VOUT=0V, When CE voltage is applied Lx determine "L"

-

V 5

When connected to ext. components (XC9208 only)

IOUT=1mA (*4)

PWM "H" Voltage

VPWMH

VIN-0.3

-

V

1

When connected to ext. components (XC9208 only)

IOUT=1mA (*4)

PWM "L" Voltage

VPWML

VIN-1.0

V

5

µA

CE "H" Current

CE "L" Current

ICEH

ICEL

CE=VIN=5.5V, VOUT=0V

-0.1

-

0.1

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

When connected to ext. components

CE=0V ꢀVIN, IOUT=1mA

Soft start time

Latch Time

TSS

Tlat

0.8

-

6.0

ms

1

6

When connected to ext. components

12.0

VIN=CE=5.0V, short VOUT by 1Ω resistance (*5)

Test condition : Unless otherwise stated, VIN = 3.6V

*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

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.

*4

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

generating.

*5

Semiconductor Ltd.

Data Sheet

6

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" ELECTRICAL CHARACTERISTICS

XC9206A33CMR, XC9207A33CMR, XC9208A33CMR

VOUT=3.3V, FOSC=1.2MHz, Ta=25^OC

MIN TYP MAX

PARAMETER

SYMBOL

CONDITIONS

When connected to ext. components

CE=VIN, IOUT=30mA

UNIT CIRCUIT

Output Voltage

VOUT

3.234 3.300 3.366

V

1

(XC9206, 9207)

(XC9208)

1.8

2.0

500

-

6.0

-

Operating Voltage Range

VIN

1

2

Maximum Output Current

U.V.L.O Voltage

IOUTMAX When connected to ext. components

mA

V

CE=VIN, VOUT=0V,

VUVLO

1.00

1.40

1.78

Voltage which Lx pin voltage holding "L" level (*1)

Supply Current 1

Supply Current 2

IDD1

IDD2

µA 3

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

3

µA

Stand-by Current

Istb

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

26

32

38

0

%

1

2

1

4

Maximum Duty Cycle

Minimum Duty Cycle

Efficiency (*2)

MAXDTY CE=VIN, VOUT=0V

MINDTY CE=VOUT=VIN

100

-

%

-

EFFI

RLx

When connected to ext. components, CE=VIN, IOUT=100mA

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

92

0.4

600

-

%

Lx SW ON Resistance

Current Limit

-

0.9

-

Ω

ILIM

VIN=CE=5.0V, VOUT=0V

-

mA

VOUT=0V, When CE voltage is

applied Lx determine "H"

(XC9206, XC9207)

(XC9208)

1.2

0.9

VIN

CE "H" Voltage

CE "L" Voltage

VCEH

VCEL

V

5

1

-

VOUT=0V, When CE voltage is applied

Lx determine "L"

VSS

VIN-0.3

-

0.3

-

When connected to ext. components (XC9208 only)

IOUT=1mA (*4)

PWM "H" Voltage

PWM "L" Voltage

VPWMH

VPWML

When connected to ext. components (XC9208 only)

IOUT=1mA (*4)

VIN-1.0

5

µA

CE "H" Current

CE "L" Current

ICEH

ICEL

CE=VIN=5.5V, VOUT=0V

-0.1

-

0.1

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

When connected to ext. components

CE=0V ꢀVIN, IOUT=1mA

Soft start time

Latch Time

TSS

Tlat

0.8

-

6.0

ms

1

6

When connected to ext. components

12.0

VIN=CE=5.0V, short VOUT by 1Ω resistance (*5)

Test condition : Unless otherwise stated, VIN = 5.0V

*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

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.

*4

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

generating.

*5

Semiconductor Ltd.

Data Sheet

7

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" TYPICAL APPLICATION CIRCUIT

$

FOSC = 1.2MHz

4.7µH (CDRH3D16 SUMIDA) L :

CRS02 (TOSHIBA)

$ FOSC = 600kHz

CE/MODE

L :

10µH

(CDRH4D18C SUMIDA)

VOUT

MODE

CE/

3

4

5

SD :

CIN :

CL :

SD :

CIN :

CL :

CRS02 (TOSHIBA)

4.7µF

10µF

(Ceramic)

4.7µF

10µF

(Ceramic)

VSS

Lx

2

1

VOUT

(500mA)

L

VIN

$

FOSC = 300kHz

CL

(ceramic)

CIN

(ceramic)

SD

L :

22µH

(CDRH4D28C SUMIDA)

SD :

CIN :

CL :

CRS02 (TOSHIBA)

4.7µF

10µF

(Ceramic)

* XC9206/9207/9208 series wire connection

" 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)

1VIN = 5.5V, VOUT=1.8V, IOUT=10mA

L

CH1 : Lx

: 4.7µH

: CRS02

: 4.7µF

: 10µF

CDRH3D16 SUMIDA

TOSHIBA

SD

CIN

CL

Ceramic

CH2 : VOUT

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)

2VIN = 2.0V, VOUT=1.8V, IOUT=60mA

CH1 : Lx

L

: 4.7µH

: CRS02

: 4.7µF

: 10µF

CDRH3D16 SUMIDA

TOSHIBA

SD

CIN

CL

CH2 : VOUT

Ceramic

AC-COUPLED

Ceramic

Semiconductor Ltd.

Data Sheet

8

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

# Application Information (Continued)

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

L

: OnDuty ratio of Pch Driver Transistor

: Coil Inductance Value

FOSC

: Oscillation Frequency

6. When the peak current which exceeds limit current flows within the specified time, the built-in Pch 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.

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)

1VIN=4.2V, VOUT=1.8V, IOUT=180mA

2VIN=4.2V, VOUT=1.8V, IOUT=60mA

CH1:Lx

CH2:VOUT

AC-COUPLED

3VIN=3.6V, VOUT=1.8V, IOUT=30mA

CH1:Lx

CH2:VOUT

L

: 4.7µH

: CRS02

: 4.7µF

: 10µF

CDRH3D16 SUMIDA

TOSHIBA

SD

CIN

CL

AC-COUPLED

Ceramic

Semiconductor Ltd.

Data Sheet

9

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

CE/

MODE

VIN

GND

# 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.

5

4

CIN

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

possible, and connect it to GND with the shortest possible PCB

traces.

CL

SD

1

2

3

Lx

3. Wire external components as close to the IC as possible and

use thick, short connecting traces to reduce the circuit impedance.

VIN Line

L

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.

GND Line

Other Line

VOUT

(Through Holeto SD )

" 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.

< Current Limit >

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 1through 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

CurrentLimitLEVEL

IOUT

0mA

VSS

VOUT

LX

CE/MODE

Restart

VIN

Semiconductor Ltd.

Data Sheet

10

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" 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 0 µA (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 0 µA (TYP.).

#

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

(A)

SW_CE

STATUS

Chip Disable

ON

VIN

VDD

OFF

PWM control (XC9206), PWM/PFM automatic switching control (XC9207)

R1

SW_CE

CE/MODE

(B)

SW_CE

STATUS

PWM control (XC9206), PWM/PFM automatic switching control (XC9207)

Chip Disable

SW_CE

R2

ON

OFF

(A)

(B)

#

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

(A)

SW_CE SW_PMW/PFM

STATUS

Synchronous PWM control

VIN

ON

OFF

*

VDD

ON

OFF

Non-synchronous PWM/PFM automatic switching control

Chip Disable

RM1

RM2

CE/MODE

SW_PWM/PFM

RM1

SW_CE

CE/MODE

(B)

SW_PWM/PFM

SW_CE

RM2

SW_CE SW_PMW/PFM

STATUS

Chip Disable

ON

OFF

*

(A)

(B)

ON

OFF

Non-synchronous PWM/PFM automatic switching control

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.

Semiconductor Ltd.

Data Sheet

11

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" TEST CIRCUITS

Circuit 1

Circuit 2

CE

/MODE

VOUT

VSS

4

3

2

VOUT

CE

4

3

2

1

/MODE

VSS

Lx

L

VIN

Lx

5

1

VIN

5

SD

V

CL

CIN

RL

200Ω

1µF

Circuit 3

Circuit 4

VOUT

CE

/MODE

VOUT

CE

4

3

2

1

4

3

2

1

/MODE

VSS

Lx

VIN

A

5

V

ꢁ

1µF

Circuit 5

Circuit 6

H

CE

/MODE

CE

/MODE

VOUT

4

3

2

A

4

3

L

VSS

Lx

VSS

2

1

L

VIN

5

1

Lx

VIN

5

SD

V

1kΩ

CL

CIN

1µF

1Ω

1.2MHz

600kHz

300kHz

4.7µF (ceramic)

10µF (ceramic)

4.7µH

4.7µF (ceramic)

10µF (ceramic)

10µH

4.7µF (ceramic)

10µF (ceramic)

22µH

CIN

CL

L

SD

Schottky Diode

Semiconductor Ltd.

Data Sheet

12

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

" TYPICAL PERFORMANCE CHARACTERISTICS

(1) Output Voltage vs. Output Current

XC9208A18C

XC9208A186

VOUT=1.8V (Oscillation Frequency1.2MHz)

VOUT=1.8V (Oscillation Frequency 600kHz)

CIN:4.7µF,CL:10µF, L:4.7µH(CDRH3D16),

CIN:4.7µF,CL:10µF, L:10µH(CDRH4D18C),

SD:CRS02, Topr=25^OC

2

SD:CRS02, Topr=25^OC

2

PWM/PFM

Switching Control

PWM/PFM

Switching Control

1.9

3.6V, 4.2V

VIN=2.4V

1.8

1.7

1.6

1.5

1.8

1.7

1.6

1.5

PWM

Control

PWM

Control

3.6V

4.2V

VIN=2.4V

0.1

1

10

100

1000

0.1

1

10

100

1000

Output Current IOUT (mA)

XC9208A183

VOUT=1.8V (Oscillation Frequency 300kHz)

CIN:4.7µF,CL:10µF, L:22µH(CDRH4D28C),

SD:CRS02, Topr=25^OC

2

1.9

PWM/PFM

Switching Control

3.6V, 4.2V

VIN=2.4V

1.8

1.7

1.6

1.5

PWM Control

0.1

1

10

100

1000

Output Current IOUT (mA)

Semiconductor Ltd.

Data Sheet

13

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

(2) Efficiency vs. Output Current

XC9208A18C

XC9208A186

VOUT=1.8V (Oscillation Frequency 1.2MHz)

VOUT=1.8V (Oscillation Frequency 600kHz)

CIN:4.7µF,CL:10µF, L:4.7µH(CDRH3D16),

CIN:4.7µF,CL:10µF, L:10µH(CDRH4D18C),

SD:CRS02, Topr=25^OC

100

PWM/PFM Switching

Control

PWM/PFM

Switching Control

90

80

70

60

50

40

30

20

10

0

90

80

70

60

50

40

30

20

10

0

VIN=2.4V

3.6V

VIN=2.4V

3.6V

4.2V

PWM

Control

PWM

Control

0.1

1

10

100

1000

0.1

1

10

100

1000

Output Current IOUT (mA)

XC9208A183

VOUT=1.8V (Oscillation Frequency 300kHz)

CIN:4.7µF,CL:10µF, L:22µH(CDRH4D28C),

SD:CRS02, Topr=25^OC

100

PWM/PFM

90

80

70

60

50

40

30

20

10

0

Switching Control

3.6V

VIN=2.4V

4.2V

PWM Control

0.1

1

10

100

1000

Output Current IOUT (mA)

Semiconductor Ltd.

Data Sheet

14

XC9206 / 9207/ 9208 Series

PWM, PWM/PFM Switchable Step-Down DC/DC Converters with Driver Transistor Built-In

(3) Ripple Voltage vs. Output Current

XC9208A18C

XC9208A186

VOUT=1.8V (Oscillation Frequency 1.2MHz)

VOUT=1.8V (Oscillation Frequency 600kHz)

CIN:4.7µF,CL:10µF, L:4.7µH(CDRH3D16),

CIN:4.7µF,CL:10µF, L:10µH(CDRH4D18C),

SD:CRS02, Topr=25^OC

100

80

60

40

20

0

80

60

40

20

0

PWM Control

4.2V

PWM Control

4.2V

PWM/PFM Switching

Control

PWM/PFM Switching

Control

3.6V

VIN=2.4V

0.1

1

10

100

1000

0.1

1

10

100

1000

Output Current IOUT (mA)

XC9208A183

VOUT=1.8V (Oscillation Frequency 300kHz)

CIN:4.7µF,CL:10µF, L:22µH(CDRH3D28C),

SD:CRS02, Topr=25^OC

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)

Semiconductor Ltd.

Data Sheet

15


型号：	XC9206A2LCMR
厂家：	Torex Semiconductor
描述：	Switching Regulator/Controller
文件：	总15页 (文件大小：172K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

XC9206A2LCMR [TOREX]

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