UCL5811

Preliminary

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

2 of 5

www.unisonic.com.tw

QW-R125-060.a



MARKING



PIN CONFIGURATION



PIN DESCRIPTION

PIN NO.

PIN NAME

DESCRIPTION

1

COMP

Loop compensation pin. Connect a RC network across this pin and ground to stabilize the

control loop.

2

FB

Detect output diode zero current to regulate output current. Connected to a resistor divider

for sensing the reflected voltage from auxiliary winding.

3

CS

Current sense pin, a resistor connects to sense the MOSFET current.

4

GND

Power Ground.

5

DRV

Output to drive the external power MOSFET, Maximum Voltage is internally clamped to

18V.

6

Power Supply pin.

7,8

NC

No connect.



BLOCK DIAGRAM

Reference

FB

Logic

OVP_CMP

SCP_CMP

GM

QR_OSC

S

R

DRV

OTP

OVP

UVLO

FB_CLAMP

DETECT_TOFF

3.6V

LEB

CS_LIMIT

+

-

1.2V

+

-

DRV

5

GND

4

3

1

2

6

COMP

CS

ZVD