RT9726

2

DS9726-01 April 2011

www.richtek.com

Function Block Diagram

Pin No.

Pin Name

Pin Function

1

VIN

High Voltage Power Supply Input. This pin should be bypassed with a 0.1

μF capacitor

to ground.

2

GND

Ground pin. Tie the ground pin close to temperature sensing thermistor.

3

NTC

This pin should connect a thermistor resistor to ground. The NTC pin will sense the

external thermistor cross voltage and provide typical 50%REF over-temperature

threshold for OT pin.

4

OT

Open-drain and active-low output. OT will go LOW when NTC pin is lower than typical

50%REF over-temperature threshold.

5

REF

Reference Output. This pin should connect with a resistor to NTC pin to set the over-

temperature threshold.

6

EN

Chip Enable (Active High). This pin can be used for the over-temperature threshold

hysteresis setting.

Functional Pin Description

REF

Hysteresis

Control

+

-

EN

REF

VIN

GND

NTC

OT