as2591 austriamicrosystems, as2591 Datasheet - Page 5

• Manufacturer Part Number: as2591
• Description: 16-digit Lcd Driver Cmos Integrated Circuit
• Manufacturer: austriamicrosystems

Letters/Signs:
Letters/Signs:
Preliminary
Functional Description
AS2591 is a CMOS mixed-mode integrated circuit for
driving LCDs 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
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 counts (except commands for displaying digits
"-", "
second
SHIFT&WRITE or BLINKING command. The normal
display appears immediately after receiving a WRITE-
DIGIT, SHIFT&WRITE, or BLINKING command.
Supply Arrangement
The device is supplied through V
reference voltages (V
and segment outputs are set at pin V
to 3.27V the segment output voltage is 2.97V
(middle).
LCD Digit Code
Rev. 1.0
Code [HEX]:
Code [HEX]:
Code [HEX]:
o
Number:
", "o"). The content of the timer is displayed 5
Display:
Display:
Display: |_|
after
a
chip-select signal. The device also
receiving
|_|
| |
| |
01
0A
15
|
|
_
H
1
a
33
, V
23
, and V
|_
|_
|_|
0B
02
16
the
_
_|
|
2
b
I
last
13
|_
|
|_
0C
) for the backplane
03
17
_
_|
_|
_
3
L
c
DD
LCD
. The internal
WRITE-DIGIT,
. With V
|_|
|_|
| |
0D
04
18
_|
N
_
4
d
|
LCD
|_
|_
|_
|_|
0E
05
19
set
_
_|
_
O
_
5
e
Page 5
|_
|_|
|_
|
|_|
|
0F
1A
06
_
_
P
_
6
f
This voltage can be programmed through the serial
bus to 2.83V (low) or 3.09V (high) for optimising the
contrast of the LCD. The 1/3, 2/3, and 3/3 voltages
are generated internally (see Figure 4: Supply
arrangement). In applications with varying V
recommended to insert a voltage regulator at V
order to assure a constant contrast (see also
application note AN525 for further information).
AS2525
From
|
1B
07
10
_
_
_
_
R
_
7
#
|
|
Figure 4: Supply arrangement
|_|
|_|
|_
|_
|_
1C
08
11
_
8
T
*
|
V
V
LCD
V
|_|
|_|
SS
DD
1D
09
12
_
_|
_
U
9
-
Contrast
| |
|_|
|
|_
|_|
control
1E
00
13
_
_
_
0
(
"
1F
14
_
_|
)
|
V
DD
AS2591
May 1999
DD
, it is
LCD
Contrast
control
V
V
V
33
23
13
in