Purdy AND721GST/GST-LED - Manual (Page 2)

Intelligent Character Display
AND721GST/GST-LED
Purdy Electronics Corporation • 720 Palomar Avenue • Sunnyvale, CA 94085
7-27-99 Tel: 408.523.8200 • Fax: 408.733.1287 • [email protected] • www.purdyelectronics.com 2
Power Supply
The LCD panel is driven by the voltage V
DD
–V
O
, so an
adjustable V
O
is required for contrast control and
temperature compensation.
Power Supply Block Diagram
Block Diagram
Dimensional Outline
1 GND Ground
2 V
DD
+5 Power Supply
3 V
O
LCD Drive Voltage
4 RS
“H” Data Input
“L” Command Input
5 R/W Read/Write
6 E Enable
7 DB0
Data Bus
DB0-DB7 are for 8-bit operation
DB4-DB7 are for 4-bit operation
8 DB1
9 DB2
10 DB3
11 DB4
12 DB5
13 DB6
14 DB7
15 LED LED Anode (+)
16 LED LED Cathode Ground
Connector Pin Assignment
Pin # Signal Function
Temperature Variations
Temperature V
DD
–V
O
0°C 5.00
+25°C 4.75
+50°C 4.50
V
DD
V
O
GND
V
DD
– V
O
V
DD
– V
O
= LCD Drive Voltage
VR10 to 20 k Ω
VR V
DD
(+5V)
Driver
Driver
Driver Driver
Controller/
Driver
16 16
16
40
4
4
40 40
40
20 4
20
LCD
E
R/W
RS
V
DD
V
O
GND
DBO-DB7 8
Connector Pin Assignment