HT9201B datasheet(2/7 Pages) HOLTEK

No de pièce	HT9201B

Description	Simple Tone Dialer

PDF	7 Pages

Scroll/Zoom	100%

Fabricant	HOLTEK [Holtek Semiconductor Inc]

Site Internet	http://www.holtek.com

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2 / 7 page

Keyboard Information

Block Diagram

Pin Description

Pin Name

I/O

Internal

Connection

Description

C1~C4

R1~R4

I/O

CMOS

IN/OUT

These pins form a 4

×4 keyboard matrix which can perform

keyboard input detection and dialing specification setting

functions. When the chip is in the standby mode the column

group (C1~C4) remains low whereas the row group (R1~R4) is

set high for key input detection.

An inexpensive single contact 4

×4 keyboard can be used as an

input device. Pressing a key connects a single column to a

single row, and actuates the system oscillator which result in

a dialing signal output. If more than two keys are pressed at a

time, no response occurs. The key-in debounce time is 20ms.

Refer to the keyboard information for keyboard arrangement.

HT9201A/B

3rd Dec ’97

HT9201B Fiches technique(PDF) 2 Page - Holtek Semiconductor Inc