September 30, 2003 Ver. 1

Synchronous Step-Down DC/DC Converter with Built-In LDO Regulator in Parallel plus Voltage Detector

2.4V ~ 6.0V

DC/DC

0.9 ~ 4.0V (

±2%)

VR

0.9 ~ 4.0V (

±2%)

VD

0.9 ~ 5.0V (

±2%)

300kHz, 600kHz, 1.2MHz

DC/DC

600mA

VR

200mA

MSOP-10, USP-10

Input Voltage Range :

2.4V ~ 6.0V

Load Capacitors :

Ceramic Capacitors Compatible

(Low ESR Capacitors)

VD Function :

Sense internally either

VDD, DCOUT, or VROUT.

Nch Open Drain Output

<DC/DC Converter>

Output Voltage Range :

0.9 ~ 4.0V (

±2%)

Output Current :

600mA

Controls :

PWM Control

Oscillation Frequency :

300kHz, 600kHz, 1.2MHz

<Regulator>

Output Voltage Range :

0.9 ~ 4.0V (

±2%)

Current Limit

300mA

Dropout Voltage :

80mV @ IOUT=100mA (VOUT=2.8V)

High Ripple Rejection

60dB @1kHz (VOUT=2.8V)

XC9509 Series

PWM, PWM / PFM Automatic

Switching External

The XC9509 series consists of a step-down DC/DC converter and a

high-speed LDO regulator connected in parallel with the DC/DC

converter's output. A voltage detector is also built-in. Since the input

for the LDO voltage regulator block comes from the input power supply,

it is suited for use with various applications.

The DC/DC converter block incorporates a P-Channel driver transistor

and a synchronous N-Channel switching transistor. With an external

coil, diode and two capacitors, the XC9509 can deliver output currents

up to 600mA at efficiencies over 90%. The XC9509 is designed for

use with small ceramic capacitors.

A choice of three switching frequencies are available, 300 kHz,

600 kHz, and 1.2 MHz.

Output voltage settings for the DC/DC and VR are set-up internally in

0.1V steps within the range of 0.9V to 4.0V (

± 2.0%). For the VD, the

range is of 0.9V to 5.0V (

± 2.0%).

The soft start time of the series is internally set to 5ms. 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 1.4 V or

lower.

The functions of the MODE pin can be selected via the external control

pin to switch the DC/DC control mode and the disable pin to shut down

either the DC/DC block or the regulator block.

MSOP-10

(TOP VIEW)

LX

DCOUT

VROUT

MODE

AGND

PGND

CE

PVDD

AVDD

1

CL2

L

CL1

SD

2

3

4

5

6

7

8

9

10

CIN2

VDOUT

VROUT

DCOUT

Semiconductor Ltd.

CIN1

XC9509Hxxxx

0

10

20

30

40

50

60

70

80

90

100

0.1

1

10

100

1000

DC/DC Output Current IDOUT (mA)

PWM/PFM Switching Control

PWM Control

DC/DC Efficiency

(DCOUT:2.2V, 1.2MHz)

CIN:4.7uF(ceramic), CL1:10uF(ceramic), CL2: 1uF(ceramic)

Data Sheet

1