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

! Input Voltage Range

: 1.8V ~ 6.0V (XC9206/XC9207)

: 2.0V ~ 6.0V (XC9208)

! Output Voltage Range

: 0.9V ~ 4.0V

! Oscillation Frequency

: 300kHz, 600kHz, 1.2MHz

! Output Current

: 500mA

! Maximum Duty Ratio

: 100%

! Small Package

: SOT-25

! PWM/PFM Switching Control (XC9207 / XC9208)

! Ceramic Capacitor Compatible

P ch driver Tr. Built-in

ON resistance 0.4

Ω

Output Voltage Range

0.9V ~ 4.0V (100mV steps)

Fixed output voltage accuracy ±2%

Oscillation Frequency

300kHz, 600kHz, 1.2MHz

Fixed oscillation frequency

accuracy ±15%

Stand-by function

Istb = 1

µA (MAX.)

Current Limiter Circuit built-in

600mA

Small Package

SOT-25

Soft start circuit built-in

XC9206 / 9207/ 9208 Series

The XC9206/9207/9208 series is a group of DC/DC converters with a

built-in 0.4

Ω 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.

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 1.0

µA 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.

XC9208A18C

VOUT=1.8V (Oscillation Frequency 1.2MHz)

0

10

20

30

40

50

60

70

80

90

100

0.1

1

10

100

1000

Output Current IOUT (mA)

VIN=2.4V

3.6V

4.2V

PWM/PFM

Switching Control

PWM

Control

CIN:4.7

µF,CL:10µF, L:4.7µH(CDRH3D16),

SD:CRS02, Topr=25

Semiconductor Ltd.

1

2

4

5

L

CL

(ceramic)

SD

CIN

(ceramic)

VIN

CE/MODE

VOUT

(500mA)

Lx

VOUT

CE/

MODE

VIN

VSS

3

Data Sheet

1