Hybrido telefonico
AS2591
16-Digit LCD Driver CMOS Integrated Circuit
Austria Mikro Systeme International AG
Key Features
G 16-digit LCD driver on a 44 pin CMOS chip G Operating voltage range: 3.2 to 4.8V G Low power consumption: max. 150 µA G Driving 7-segment displays with up to 16 digits and 12 symbols G Option for 12 digits G Buffer for 32 digits G 4 backplanes G 2-wire interfaceG On chip timer for showing elapsed time G Contrast adjustable G On chip oscillator using 32.768 kHz crystal G Compatible with AS2525
General Description
The AS2591 is a CMOS integrated circuit for driving a liquid crystal display intended for use in telephones. The driver can be used with 12- or 16-digit LCDs. The 2-wire serial interface is compatible with the AS2525, single-chiphandsfree telephone circuit. The device is designed for LCDs with 4 backplanes and 24 or 31 segments providing 12 or 16 7-segment digits and 12 symbols. The AS2591 also includes a timer for showing elapsed time in minutes and seconds. The contrast can be adjusted through the serial interface.
Package
Available in 44 pin TQFP.
Block Diagramme
VDD POR DI SCLK CS
DATA
BACKPLANE COUNTER
4COM1-4
SERIAL I/F
7SEGMENT DECODER SEGMENT MULTIPLEXER DIGIT MEMORY 32 DIGITS 16 S1_n
LCD
COMMAND ADDRESS DECODER CONTROL
16
S2_n
32.768 kHz OSC ELAPSE TIME COUNTER
TIMER VLCD CONTRAST VOLTAGE CONTROL
AS2591
Figure 1: Block diagram
Rev. 1.0
Page 1
May 1999
Preliminary
Pin Description
Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13 Name S2_10 S1_10 S2_11 S1_11 S2_12S1_12 S2_13 S1_13 S2_14 S1_14 S2_15 S1_15 CS Type AO Description Segment Outputs Output pins for driving segments of LCD.
AS2591
DI
Chip Select Chip select signal from CPU (e.g. AS2525).
14
DI
DI
Data Input Data input pin for serial interface.
15
SCLK
DI
Serial Clock Input Clock input pin for serial interface.
16
VDD
Supply
Positive Voltage Supply This pinis the positive power supply for the device.
17
VSS
Supply
Negative Voltage Supply This pin is the negative power supply for the device.
18 19 20
XTAL1 XTAL2 VLCD AI
Oscillator Pins Oscillator pins for connection of a 32.768 kHz crystal. LCD Reference Voltage This is the input pin for setting the internal LCD reference voltage (see also Figure 4: Supply arrangement).
21 2223 24 Continues…
COM1 COM2 COM3 COM4
AO
Backplane Outputs Ouput pins for driving backplanes of LCD.
Rev. 1.0
Page 2
May 1999
Preliminary
Pin # 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44
DI: DO: DI/O:
AS2591
Type AO Description Segment Outputs Output pins for driving segments of LCD.
Name S2_0 S1_0 S2_1 S1_1 S2_2 S1_2 S2_3 S1_3 S2_4 S1_4 S2_5 S1_5S2_6 S1_6 S2_7 S1_7 S2_8 S1_8 S2_9 S1_9
Digital Input Digital Output Digital Input/Output
AI: AO: AI/O:
Analogue Input Analogue Output Analogue Input/output
Pin Configuration
S2_10 S1_10 S2_11 S1_11 S2_12 S1_12 S2_13 S1_13 S2_14 S1_14 S2_15
S1_9 S2_9 S1_8 S2_8 S1_7 S2_7 S1_6 S2_6 S1_5 S2_5 S1_4
39
1
6
AS2591
28
17
S2_4 S1_3 S2_3 S1_2 S2_2 S1_1 S2_1 S1_0 S2_0 COM4COM3
Figure 2: Pin configuration
Rev. 1.0
S1_15 CS DI SCLK VDD V SS XTAL1 XTAL2 VLCD COM1 COM2
Page 3
May 1999
Preliminary
Typical Application
AS2591
Figure 3: Typical Application
See also application note AN525 for further information.
Rev. 1.0
Page 4
May 1999
Preliminary
Functional Description
AS2591 is a CMOS mixed-mode integrated circuit for drivingLCDs with 4 backplanes and 24 or 31 segments providing 12 or 16 7-segment digits and 12 symbols. The device is controlled via a simple 2-wire bus and a chip-select signal. The device also includes an elapse-time counter which is started 5 seconds after power-up and incremented every second. The timer is re-started whenever the device gets a WRITE-DIGIT or SHIFT&WRITE command within the first 5...
Regístrate para leer el documento completo.