UD36061

Preliminary

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

3 of 6

www.unisonic.com.tw

QW-R103-120.a



PIN CONFIGURATION



PIN DESCRIPTION

PIN NO.

PIN NAME

DESCRIPTION

1

BST

High-Side Gate Drive Boost Input. BST supplies the drive for the high-side

N-Channel MOSFET switch. Connect a 0.1μF or greater capacitor from SW to BST

to power the high side switch.

2

GND

Ground.

3

FB

Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB

with a resistive voltage divider from the output voltage. The feedback threshold is

0.8V.

4

EN

Enable Input. Pulling this pin below the specified threshold shuts the chip down.

Pulling it above the specified threshold enables the chip. Floating this pin shuts the

chip down.

5

Power Input. IN supplies the power to the IC, as well as the step-down converter

switches. Drive IN with a 3.3V to 36V power source. Bypass IN to GND with a

suitably large capacitor to eliminate noise on the input to the IC.

6

SW

Power Switching Output. SW is the switching node that supplies power to the

diode to ground is required closed to this pin to reduce switching spikes.



BLOCK DIAGRAM

5

REFFERENCE

UVLO

LOGIC

OSCILATOR

2MHz

INTERNAL

REGULATOR

ISW

ISW

SS

0.8V

0.5ms SS

SS

FB

BST

SW

GND

EN

1

6

4

3

2