Preliminary

May 23, 2002 Ver. 1-1

Externally Applied Reference Voltage (Vref)

Applications

Ceramic Capacitors Compatible

Power Supply for LCD

Input Voltage Range: 0.9V~10.0V

PDAs

Oscillation Frequency: 300kHz, 100kHz (±15%)

Cellular Phones

PWM Control (XC9106)

Palmtop Computers

PWM/PFM Automatic Switching Control (XC9107)

Portable Audio Systems

SOT-25 / USP-6B Package

Various Multi-function Power Supplies

General Description

Features

Input Voltage Range:

0.9V ~ 10.0V

Power Supply Voltage Range:

1.8V ~ 10.0V and more than Vref+0.7V

0.8V ~ 2.5V (

±2.0%)

Output Voltage:

Vref x external split resistor ratio

Oscillation Frequency:

300kHz, 100kHz

±15%

Output Current:

more than 30mA

Controls:

PWM (XC9106)

PWM/PFM auto-switching (XC9107)

High Efficiency:

85% (TYP.)

Stand-by Current:

ISTB=1

.0µA (MAX.)

Load Capacitors:

Low ESR capacitors compatible

Packages:

SOT-25, USP-6B

Typical Application Circuit

Electrical Characteristics

1

XC9106 / 07 Series

PWM Control, PWM/PFM Switching Control,

Step-up DC/DC Converters

Externally Applied Reference Voltage (Vref)

components are used as in the circuits

below .)

The XC9106 / 07 series are step-up DC/DC controller ICs with

an externally applied reference voltage (Vref).

Output voltage will be set with external resistors (RFB1 and 2)

and Vref value. The series make it easy to control output

voltage externally and are suited to software applications that

need to vary voltage, such as LCD power supply for PDA.

Output will be stable no matter which load capacitors are used

Ω will

be required and phase compensation will be achieved. This

makes the use of ceramic capacitors much easier, and allows

for lower output ripple and reduced PCB area requirements.

Tantalum and electrolytic capacitors can also be used, in which

Oscillation frequencies of high clock, low ripple 300kHz and low

supply current 100kHz are available.

The XC9107 series are PWM/PFM automatic switching

controlled. Control switches from PWM to PFM during light

applications such as a small LCD, even using ceramic capacitor.

loads with the XC9107 and the series is highly efficient from

light loads to large output currents. By bringing the whole circuit

down while the series is in the stand-by mode (CE/PWM pin :

low), supply current can be reduced to less than 1.0

µA.

0

5

10

15

20

25

30

0.0

0.5

1.0

1.5

2.0

2.5

3.0

Vref (V)

0

5

10

15

20

25

30

0.1

1

10

100

1000

2.0V

Vref=0.8V

1.5V

2.5V

Circuit as left

XC9107D003MR

XC9107D003MR

Circuit as left

L : 10

µH

SD : MA737

CFB : 27pF

Nch Power

MOS FET

2SK2159

RFB2 :

30k

Ω

RFB1 :

270k

Ω

D/A converter

Ceramic CL :

10

µF

CE/Vref

CIN

RSENSE : 100m

Ω

for Ceramic CL

0.8V~2.5V

3

2

15

4

*