Pin Assignment

Pin Description

Pin Name

I/O

Description

EN

I

Shutdown & Dimming control input. Don

¢t allow this pin to float.

GND

¾

Signal Ground.

FB

I

Feedback pin. Reference voltage. The HT7938 feedback voltage is 200mV. Connect the

sense resistor from FB to GND to set the LED current. Calculate resistor value according to

R

mV

I

FB

LED

=

200

.

SW

I

Switching pin. Internal power MOSFET drain. Connected to inductor and diode.

VIN

I

Input supply pin. The input supply pin for the IC. Connect VIN to a supply voltage between

2.6V~5.5V.

OVP

O

Over voltage protection pin which is connected to the output.

Absolute Maximum Ratings

Input Voltage...........................................................6.0V

SW Voltage..............................................................46V

FB Voltage ..............................................................6.0V

EN ..........................................................................6.0V

OVP Voltage ............................................................46V

Operating Temperature Range .............

-40°Cto+85°C

Storage Temperature Range ..............

-55°C to +150°C

Maximum Junction Temperature........................+150

°C

Note: These are stress ratings only. Stresses exceeding the range specified under

²Absolute Maximum Ratings² may

cause substantial damage to the device. Functional operation of this device at other conditions beyond those listed

in the specification is not implied and prolonged exposure to extreme conditions may affect device reliability.

HT7938

Rev 1.10

2

March 19, 2010

S W

G N D

T o p V i e w

V I N

E N

F B

1

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