1

Data Sheet

AS2590

Rev. 1

Dec. 1993

LC DISPLAY DRIVER WITH 18 DIGITS,

6 SYMBOLS AND CLOCK/TIMER

®

Austria Mikro Systeme International

KEYBOARD

Vss

DIALLER

CONTROLLER

AS2574A/B

SDA

SCL

X1

X2

V23

V13

BIAS

MS

Vss

32.768kHz

SPEECH CIRCUIT

Key Features

u Very low operating current, typ. 30

µA @ 3V

u Low power oscillator using 32.768 kHz Xtal

u 2-wire interface compatible to AS2574B

u 18 digits by 7 segments

u 6 symbols

u 24 hour clock showing hours and minutes

u Timer automatically showing elapsed time in

minutes and seconds after each telephone

conversation

u 33 LCD segment outputs and 4 LCD backplane

outputs

u 4 times multiplex mode with a cycle time of 128 Hz

u Mode select pin for selecting clock function

General Description

The AS2590 is an integrated CMOS device for driving a

liquid crystal display intended for use in telephones. The

2-wire serial interface is compatible to the dialler

AS2574B.

The extreme low operating current allows the circuit to

be operational also during on-hook which is necessary

in order to the use of the clock function. In on-hook

condition the circuit can be supplied by a small leakage

current from the telephone line or from a small 3V

battery.

Whether the oscillator shall continue operating or be

stopped during on-hook is determined by the mode pin,

MS.

Package

Available in 48 pin DIP and 52 pin PLCC.