DESCRIPTION
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SA8806A
FEATURES
n
Drives up to 64 segments
n
Standard parallel interface
n
Operates over a wide temperature
range
64 SEGMENT LIQUID CRYSTAL DISPLAY DRIVER
PARALLEL INTERFACE
PIN CONNECTIONS
4072
PDS039-SA8806-001 REV. D 12-09-1995
n
External contrast control
n
Low power CMOS
The SAMES SA8806A Liquid Crystal
Display (LCD) Driver is capable of driving
up to 64 LCD segments and is designed for
displays having 4 track multiplexed
backplanes.
The SA8806A includes an on-chip
oscillator. The device may be programmed
from a standard P or C Bus.
This LCD driver is ideal for any -Controller
based system requiring up to an 8 digit
LCD display.
The SA8806A integrated circuit is available
in both 40 pin dual-in-line plastic (DIP-40),
as well as 44 pin plastic leaded chip carrier
(PLCC-44) package types.
Package: DIP-40
EN
DR-00562
GND
VR[1]
VR[2]
VR[3]
VR[0]
RES
CLK
WR
RD
CS
AD[3]
AD[2]
AD[1]
AD[0]
V
D[3]
D[2]
D[1]
D[0]
DD
VS[11]
VS[13]
N.C
VS[14]
VS[15]
VS[12]
VS[9]
VS[10]
VS[5]
VS[6]
VS[7]
VS[8]
VS[2]
VS[3]
VS[4]
VS[1]
VI1
VI1/3
VI2/3
VS[0]
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PIN CONNECTIONS
BLOCK DIAGRAM
Package: PLCC-44
VS[7]
RD
D[2]
DR-00563
D[0]
D[1]
AD[0]
AD[1]
AD[2]
WR
AD[3]
D[3]
VI1/3
VI2/3
N.C.
VS[0]
DD
VS[1]
VI1
V
VS[4]
VS[3]
VS[6]
VS[5]
VS[2]
VR[2]
N.C.
CS
RES
CLK
EN
GND
VR[3]
VS[9]
VS[8]
VS[11]
VS[10]
N.C.
VR[1]
N.C
VR[0]
N.C.
VS[15]
VS[14]
VS[13]
VS[12]
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ABSOLUTE MAXIMUM RATINGS*
Parameter
Symbol
Min
Max
Unit
Supply Voltage
V
DD
-V
SS
-0.3
6.0
V
Current on any pin
I
PIN
-100
+100
mA
Storage Temperature
T
STG
-40
+125
C
Operating Temperature
T
O
-25
+85
C
* Stresses above those listed under "Absolute Maximum Ratings" may cause permanent
damage to the device. This is a stress rating only. Functional operation of the device
at these or any other condition above those indicated in the operational sections of this
specification, is not implied. Exposure to Absolute Maximum Ratings for extended
periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(Over the temperature range -10C to +70C
#
, V
DD
= 5V, V
SS
= 0V unless otherwise
specified.)
Parameter
Symbol
Min
Typ
Max Unit Condition
Supply Voltage
V
DD
-V
SS
4.5
5.0
5.5
V
Supply Current
I
DD
100
A
LCD ON Voltages
V
ON
V
DD
& V
SS
V
LCD OFF Voltages
V
OFF
1/3V
DD
& 2/3 V
DD
V
#
Extended Operating Temperature Range available on request.
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PIN DESCRIPTION
Pin
Pin
PLCC-44 DIP-40
29
16
GND
Ground
13
1
V
DD
Positive Supply Voltage
17
5
D[0]
Data inputs/outputs
16
4
D[1]
15
3
D[2]
14
2
D[3]
21
9
AD[0]
Data address inputs
20
8
AD[1]
19
7
AD[2]
18
6
AD[3]
22
10
WR
Write Enable input, active low
23
11
RD
Read Enable input, active low
25
12
CS
Chip Select input, active low
26
13
RES
Reset input, active low
27
14
CLK
Oscillator Input
8
37
VS[0]
LCD segment driver outputs
7
36
VS[1]
6
35
VS[2]
5
34
VS[3]
4
33
VS[4]
3
32
VS[5]
2
31
VS[6]
1
30
VS[7]
43
29
VS[8]
42
28
VS[9]
41
27
VS[10]
40
26
VS[11]
39
25
VS[12]
38
24
VS[13]
37
23
VS[14]
36
22
VS[15]
Designation Description
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PIN DESCRIPTION (Continued)
Pin
Pin
PLCC-44 DIP-40
33
20
VR[0]
LCD backplane driver outputs
32
19
VR[1]
31
18
VR[2]
30
17
VR[3]
28
15
EN
LCD Voltage Divider Enable input, active low
11
40
VI1
Optional external LCD voltage inputs
10
39
VI1/3
9
38
VI2/3
34
21
NC
Not connected
12
NC
24
NC
35
NC
44
NC
Designation Description
FUNCTIONAL DESCRIPTION
The SA8806A is a CMOS Liquid Crystal Display Driver integrated circuit for displays,
having 4 track multipexed backplanes and up to 64 LCD segments.
The integrated circuit has a parallel interface, with external contract control and a low
power mode.
1.
Parallel Interface
Read Mode: With CS and RD both active (low), the data corresponding to the
selected address, is switched to the output.
The Read cycle timing diagram is given below:
Diagram 1: Read Cycle
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Write Mode: With CS and WR both active (low), the data corresponding to the
address selected, is latched into memory.
The Write cycle timing diagram is given below:
2.
LCD Display
The SA8806A LCD Driver is capable of driving a 4 backplane, 8 digit (7 segment)
display, plus decimal points.
The most significant digit is addressed by columns VS[14] and VS[15] and the least
significant digit; by VS[0] and VS[1]. The display segments addressed via the
column outputs are given in a typical configuration below:
Diagram 2: Write Cycle
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The data in memory is constantly being displayed on the liquid crystal display. New
data is displayed as soon as it is latched into memory.
When a high level (+5V) on a backplane driver output corresponds with a low level
(0V) on a segment driver output (or vice versa), the LCD segment to which they are
connected, will be activated (see Diagram 3).
The backplane multiplex rate is determined by the clock frequency on the CLK input.
Diagram 3: LCD Driving Signals
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3.
LCD Character Mapping
The device has 16 address locations, A0 - A15 which correspond to VS[0] - VS[15].
Each location contains 4 bits, D[3] to D[0] which correspond to VR[3] - VR[0].
The mapping is detailed in the table below:
SEG
VS[0]
VS[1]
VS[2]
VS[3]
........
VS[12] VS[13] VS[14] VS[15]
VR[0]
0-0
1-0*
2-0
3-0
........
12-0
13-0
14-0
15-0
VR[1]
0-1
1-1
2-1
3-1
........
12-1
13-1
14-1
15-1
VR[2]
0-2
1-2
2-2
3-2
........
12-2
13-2
14-2
15-2
VR[3]
0-3
1-3
2-3
3-3
........
12-3
13-3
14-3
15-3
Note: A '1' switches the corresponding segment on.
* The address number and bit number of the byte is given, e.g. 1-0 is address 1 and
bit 0 (LSB).
4.
On-Chip LCD Voltage Divider Disable
The integrated divider for the LCD voltages can be disabled by applying a high level
on the EN input (EN = 1).
5.
Contrast Setting
The contrast may be adjusted in two ways:
An external resistor divider supplying the LCD voltage inputs VI1, VI1/3, VI2/3, with
the internal divider disabled as described in paragraph 4.
Applying an external LCD voltage on input V1, with the internal voltage divider
activated.
6.
Oscillator
The on-chip oscillator circuit requires one external capacitor for operation. The
capacitor value is calculated as follows:
C = 7F.1Hz/f
f = Required oscillator frequency
The multiplex rate is 64 times lower than the clock frequency.
TYPICAL APPLICATION
The Application Circuit (Figure 1) shows the connections for a typical application utilising
an 8 digit (7 segment) display, plus decimal points.
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ORDERING INFORMATION
Part Number
Package
SA8806APA
DIP-40
SA8806AFA
PLCC-44
Figure 1: Application Circuit
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Any Sales or technical questions may be posted to our e-mail address below:
energy@sames.co.za
For the latest updates on datasheets, please visit out web site:
http://www.sames.co.za
South African Micro-Electronic Systems (Pty) Ltd
P O Box 15888,
33 Eland Street,
Lynn East, 0039
Koedoespoort Industrial Area,
Republic of South Africa,
Pretoria,
Republic of South Africa
Tel:
012 333-6021
Tel:
Int +27 12 333-6021
Fax:
012 333-8071
Fax:
Int +27 12 333-8071
Disclaimer:
The information contained in this document is confidential and proprietary to South African Micro-
Electronic Systems (Pty) Ltd ("SAMES") and may not be copied or disclosed to a third party, in whole or in part,
without the express written consent of SAMES. The information contained herein is current as of the date of
publication; however, delivery of this document shall not under any circumstances create any implication that the
information contained herein is correct as of any time subsequent to such date. SAMES does not undertake to
inform any recipient of this document of any changes in the information contained herein, and SAMES expressly
reserves the right to make changes in such information, without notification, even if such changes would render
information contained herein inaccurate or incomplete. SAMES makes no representation or warranty that any
circuit designed by reference to the information contained herein, will function without errors and as intended by
the designer.
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