BL1102series

http://www.belling.com.cn

- 2 -

8/22/2006

Total 9 Pages

Wrote by 2006

Known from the above block diagram, it mainly made up of system clock generator, keyboard interface,

data code, random storing, read/write counter, address lock and storing, system control logic, pulse

generator, data/mode converter and double tone generator and other circuits. 。

Pin Description

Symbol

22 Pin

24 Pin

I/0

Function

Row/colum

1-4,18-

1-4,20-

I

A valid key entry is defined by a single row being

n input

22

24

Connected to a single column

X T,X T

6,7

6,7

I/0

Oscillation I/O

T/P MUTE

8

8

O

The T/P MUTE is a conventional CMOS N-channel

open drain output. When dialing and flash, the

MODE

1 4

1 6

I

Dialing mode selection.. When pin is connected to

VSS, it is double tone multi-frequency mode when it is

connected to VDD; it is pulse mode (10ppS).

HKS

9

9

I

The pin is the hook switch input HKS =1, on HOOK

state, chip in sleeping mode, no operation. HKS =0, on

HOOK state，enable chip on normal operation.

B/M

1 6

1 8

I

Break/make ratio, pin selection.

B/M=1, ratio is 60/40;

B/M=0, ratio is 66/33.

VDD, VSS

1 7, 5

19, 5

I

Power and power ground input

X MUTE

1 3

1 5

O

Inverter output. Dialing under double tone mode,

pin is high voltage；

if dialing under pulse mode, the

pin is low voltage.

HFI, HFO

--

12，13

I/O

Hands-free control details can be seen in table2.

KT

12

14

O

Key tone signal output. The frequency is1.2KHz.

Once the pin is locked, dialing starting with

"0" or "9" and all the key input afterwards will

become invalid. It will recover the original state

after on hook

LOCK Pin

Function

VDD

“0”和“9”dialing lim it

Floating

Normal

LOCK

15

(BL1102L)

17

(BL1102AL)

I

VSS

“0”dialing lim it

NC

15

(BL1102)

17

(BL1102A)

I

Not available

DP / C5

10

10

O

The DP/C5 is a conventional CMOS N-channel

open drain output. Under tone state. Output will

keep high; Under pulse state, output dialing pulse.

DTMF

11

11

O

Double tone multifrequency signal output