Block Diagram

Pin Assignment

Pin Description

Pin No.

Pin Name

Description

TO92

SOT89

SOT23

SOT23-5

¾¾¾

1

CE

Chip enable pin, high active

2232

VOUT

DC/DC converter output monitoring pin

¾¾¾

3

NC

No connection

1114

GND

Ground pin

3325

LX

Switching pin

Absolute Maximum Ratings

Storage Temperature ............................

-50°Cto125°C

Operating Temperature ...........................

-40°Cto85°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.

HT77XX

Rev 1.90

2

October 13, 2010

G N D

S O T 8 9

F r o n t V i e w

B o t t o m V i e w

S O T 2 3 - 5

C E

V O U T

G N D

V O U T

T o p V i e w

T O 9 2

V O U T

G N D

L X

V O U T

L X

L X

L X

G N D

N C

C E

V O U T

N C

1

2

3

1

2

3

1

2

3

4

5

S O T 2 3

V O U T

T o p V i e w

L X

G N D

3

2

1

L X

G N D

V O U T

G N D

V r e f

P F M C o n t r o l

O S C 1 1 5 k H z

B u f f e r

L X

C h i p E n a b l e

C E