Datasheet AS2590P, AS2590N Datasheet (Austria Mikro Systeme International)

Data Sheet

AS2590

LC DISPLAY DRIVER WITH 18 DIGITS,



Austria Mikro Systeme International

Key Features

❑ Very low operating current, typ. 30 µA @ 3V
❑ Low power oscillator using 32.768 kHz Xtal
❑ 2-wire interface compatible to AS2574B
❑ 18 digits by 7 segments
❑ 6 symbols
❑ 24 hour clock showing hours and minutes
❑ Timer automatically showing elapsed time in

minutes and seconds after each telephone
conversation

❑ 33 LCD segment outputs and 4 LCD backplane

outputs

❑ 4 times multiplex mode with a cycle time of 128 Hz
❑ Mode select pin for selecting clock function

Package

Available in 48 pin DIP and 52 pin PLCC.

6 SYMBOLS AND CLOCK/TIMER

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.

KEYBOARD

VDD

DIALLER

CONTROLLER

AS2574A/B

Vss

SPEECH CIRCUIT

V

DD

V23

V13

LCD

V

SDA
SCL

MS

X1

X2

AS2590

BIAS

Vss

32.768kHz

Rev. 1

1

Dec. 1993

Data Sheet

Pin Description

DIL PLCC Symbol Function

1 1 BP1 Blackplanes
2 2 BP0

3 3 S0 Segment outputs
44S1
55S2
66S3
78S4
89S5

910S6
10 11 S7
11 12 S8
12 13 S9

13 14 V1/3 1/3 of VDD pin for external voltage divider
14 15 S10 Segment outputs

15 16 S11
16 17 S12
17 18 S13
18 19 S14
19 21 S15
20 22 S16
21 23 S17
22 24 S18
23 25 S19

AS2590

24 26 V
25 27 BP3 Back plane outputs

26 28 BP2
27 29 V2/3 2/3 of VDD pin for external voltage divider
28 30 S32 Segment outputs

29 31 S31
30 32 S30
31 34 S29
32 35 S28
33 36 S27
34 37 S26
35 38 S25
36 39 S24
37 40 S23
38 41 S22
39 42 S21
40 43 S20

41 44 V

SS

LCD

Negative supply pin

Negative supply pin for LC display

Rev. 1

2

Dec. 1993

Data Sheet

Pin Description Continued

DIL PLCC Symbol Function

42 45 SDA Serial data line input to dialler/controller
43 47 SCL Clock line input of serial data link

AS2590

44 48 V
45 49 XTAL1 Oscillator pins for 32.768 kHz crystal, a resistor and two capacitors

46 50 XTAL2
47 51 MS Mode select input: MS = VSS › clock/timer disabled

48 52 V

LCD Layout

SB3 SB5SB4SB2SB0SB1

BIAS

DD

Oscillator bias input, recommended bias resistor 2.2 MΩ

MS = VDD › clock/timer enabled

Positive supply pin

D0D1D2D3D4D5D6D7D8D9D10D11D12D13D14D15D16D

17

Figure 1

SB0 = loudspeaker on (blinking with 1 Hz)

Table 1 Segments Digits

SB1 = microphone muted (blinking with 1 Hz)
SB2 = 2nd key function enabled
SB3 = number stored
SB4 = number buffered in FIFO, not stored
SB5 = colon for clock and timer (blinking when clock is

shown)

A

G

B
C

F

E

D

Figure 2

Digit Description Segment

ABCDEFG

0 numbers on on on on on on
1 0…9 on on
2 onon onon on
3 onononon on
4 onon onon
5ononononon
6 on ononononon
7ononon
8 ononononononon
9 ononon onon
a letter A on on on on
b letter B on on on on on
c letter C on on on
d Letter D on on on on on
_ underscore on

* asterisk on on on on

# hash on on on on on

- pause on

P/T temp. MF on on on

r recall on on

Rev. 1

3

Dec. 1993

Data Sheet

AS2590

Description

Operating Modes

The following two operating modes are pin selectable:
Mode 0:

Clock and timer are disabled and the oscillator is stopped
when going on-hook (command BLANK ALL).

Mode 1:
Clock and timer functions are enabled, clock is displayed
both during off- and on-hook (assuming that clock is set).
When going from off-hook to on-hook, the timer content
(elepsed time) is displayed for 6 seconds (assuming that
a start timer command was received).

Clock

After a power up reset the clock is disabled. The clock
will not be displayed until a valid set clock procedure has
been performed (mode 1 only). The format of the clock
is hh:mm and the leading zero of the hours is suppressed
and symbol 5 (:) is blinking with a frequency of 1 Hz. The
timer is running when off-hook and displayed for 6
seconds when going on-hook. The content of the timer
(elapsed time) is shown in stead of the clock in the format
mm:ss.

- Power up; enables subsequent start timer commands.

- BLANK ALL; clears the whole display (including special
symbols) and displays the timer contents for 6 seconds
(if clock/timer function is enabled) or until a new
START TIMER/FIFO command is received. Then it
returns to normal display mode.

- if any command or data is received by the serial
interface within the time out period after a BLANK ALL
command, the timer display will be blanked or replaced
by the clock display.

The timer is displayed in the format mm:ss with the
leading zero of the minutes suppressed and symbol 5 (:)
turned on.

LCD Outputs

The 33 segment outputs and 4 backplane outputs can
drive a customized liquid crystal display in 1:4 multiplex
mode. Two reference voltages V1/3 and V2/3 are
provided by an external voltage divider.

Digits and Special Symbols

The display consists of 18 seven segment digits and 6
special symbols (see figure 1):

If a SET CLOCK command is received the display is
blanked, four underscore symbols are displayed where
the 4 digits of the clock will be entered (the 4 most right
digits) and symbol 5 is turned on (_ _ : _ _). The next 4
data words are interpreted as the time (hh mm). The
fourth digit terminates the SET CLOCK and starts the
clock with the seconds set to zero.

If less than 4 data words (digits) are received the first
command (normally a BLANK DIGITS or a BLANK ALL)
will terminate the SET CLOCK. But as the procedure
was incomplete, it is regarded as invalid and further
clock display is disabled. The next valid SET CLOCK
command will enable the clock again. The SET CLOCK
command does not effect the timer.

The time-out condition (approx. 15 seconds) when setting
clock is recognized by the dialler/controller (e.g. AS2574).
If a time-out condition occours the dialler sends a
BLANK ALL command to terminated the SET CLOCK.

Timer

The following commands effect the timer:

- START TIMER and START FIFO; they start the timer.
If the timer is already running, it cannot be restarted
by one of these commands before stopping the timer
with the BLANK ALL command.

- D0…D17; D0 is the most left seven segment digit, the
possible numbers displayed by one digit are shown in
figure 2. The symbol (_) is only displayed at D13, D14,
D16 and D17 when setting the clock.

- SB0…SB5; 6 special symbols (one segment for each
symbol only), see figure 1 for reference. If SB0
(loudspeaker on) or SB1 (microphone muted) are
turned on, they blink with a frequency of 1 Hz.

Multiplex Mode

A total of 132 segments are addressable. One output
drives 4 segments in a time multiplex mode. The 4
backplane outputs determine the currently addressed
segment (see figure 3).

Figure 3 gives the correlation between segment outputs
and addressed segments.

Data and Commands

32 different words may be received via the serial interface.
19 words are interpreted as display data for one of the
18 seven segment digits. Table 2 gives the translation
from received code to displayed symbol.

13 words are valid commands codes. The function of
each command is described in table 2, and table 4 lists
the 5 bit codes for all possible commands.

Rev. 1

4

Dec. 1993

Data Sheet

Table 2 Command Summary

NO MNEMONIC FUNCTION
1 SET LS Turns on special symbol SB0 (loudspeaker on, blinking)
2 CLEAR LS Turns off special symbol SB0
3 SET MUTE Turns on special symbol SB1 (microphone muted, blinking)
4 CLEAR MUTE Turns off special symbol SB1
5 SET 2ND Turns on special symbol SB2 (2nd function on keyboard)
6 CLEAR 2ND Turns off special symbol SB2
7 SET CLOCK Initiates clock setting; SB5 is turned on
8 START Blanks all digits, SB3 and SB4; accepts data, timer not started
9 START COPY Blanks all digits and SB4; turns on SB3, accepts data, timer not started (if not

already running)

10 START FIFO Blanks all digits and SB3; turns on SB4, accepts data, timer started (if not

already running)

11 START TIMER Blanks all digits, turns off SB3 and SB4, accepts data, timer started (if not

already running)

12 BLANK ALL Blanks all digits and all special symbols (except D13, D14, D16, D17 and SB5

when clock is running)

13 TEST MODE Turns circuit into test mode

AS2590

Table 3 Segment Mapping

SEGMENT BACKPLANE

OUTPUT BP0 BP1 BP2 BP3

S0 SB0 SB1 SB4 SB2
S1 D0/F D0/G D0/E D0/D
S2 D0/A D0/B D0/C D1/D
S3 D1/F D1/G D1/E D1/C
S4 D1/A D1/B D2/G D2/E
S5 D2/A D2/F D2/B D2/C
S6 D3/A D3/F D2/E D2/D
S7 D3/B D3/G D3/C D3/D
S8 D4/F D4/G D4/E D4/D

S9 D4/A D4/B D4/C D5/D
S10 D5/F D5/G D5/E D5/C
S11 D5/A D5/B D6/G D6/E
S12 D6/A D6/F D6/B D6/C
S13 D7/A D7/F D7/E D6/D
S14 D7/B D7/G D7/C D7/D
S15 D8/F D8/G D8/E D8/D
S16 D8/A D8/B D8/C D9/D

SEGMENT BACKPLANE

OUTPUT BP0 BP1 BP2 BP3

S17 D9/F D9/G D9/E D9/C
S18 D9/A D9/B D10/G D10/E
S19 D10/A D10/F D10/B D10/C
S20 D11/A D11/F D11/E D10/D
S21 D11/B D11/G D11/C D11/D
S22 D12/F D12/G D12/E D12/D
S23 D12/A D12/B D12/C D13/D
S24 D13/F D13/G D13/E D13/C
S25 D13/A D13/B D14/G D14/E
S26 D14/A D14/F D14/B D14/C
S27 D15/A D15/F D15/E D14/D
S28 D15/B D15/G SB5 D15/D
S29 D16/F D16/G D16/E D16/D
S30 D16/A D16/B D16/C D17/D
S31 D17/F D17/G D17/E D17/C
S32 D17/A D17/B D15/C SB3

Rev. 1

Dn/m = segment m of digit n
SBn = special symbol n

5

Dec. 1993

Data Sheet

AS2590

Active Backplane

BP0 BP1 BP2 BP3

VDD

BP0

BP1

BP2

BP3

S0

on off off off

S1

off on on on

V2/3
V1/3
Vss

V

DD

V2/3
V1/3
Vss

DD

V
V2/3
V1/3
Vss

V

DD

V2/3
V1/3
Vss

DD

V
V2/3
V1/3
Vss

V

DD

V2/3
V1/3
Vss

Figure 3 LCD driver outputs

Serial Interface

The serial interface is a one way, two line link between
the dialler (AS2574) and the display driver. The two lines
are the serial data line (SDA) and the serial clock line
(SCL). The display driver can only receive data.

Word Transfer:
Data are transferred as 5 bit words with start and stop bit.
the least significant bit is sent first after the start bit. As
long as there is no data transfer, both data and clock
lines have to remain high. Also between two words both
lines have to stay high for a specified time. Figure 4
shows the timing of the serial interface.

Start and Stop Conditions:
A start condition is detected when the data line goes
from high to low while the clock line is held high. A low

to high transition of the data line while the clock line is
high followed by a negative clock pulse indicates a stop
condition (see figure 4).

Table 4 Codes for Serial Interface

NO SYMBOL MSB B3 B2 B1 LSB HEX

1 SB0-on 0010105
2 SB0-off 0001103
3 SB1-on 1000111
4 SB1-off 0100109
5 SB2-on 0011107
6 SB2-off 111111F
7SET CLOCK 010110B
8 START 011010D

9 COPY 011110F
10 FIFO 1001113
11 TIMER 1010115
12 BLANK 111011D
13 TEST 1011117
14 0 111001C
15 1 0000000
16 2 0010004
17 3 0001002
18 4 1000010
19 5 1010014
20 6 1001012
21 7 0100008
22 8 011000C
23 9 010100A
24 a 0011006
25 b 1011016
26 c 011100E
27 d 111101E
28 * 1100018
29 # 110101A
30 – 110111B
31P/T 1100119
32 r 0000101

SDA

SCL

Rev. 1

START

#1

LSB

B0 B1 B2 B3

Figure 4 Interface Timing

MSB

B4

6

STOP

#1

WORD

GAP

START

#2

Dec. 1993

Data Sheet

AS2590

Electrical Characteristics

Absolute Maximum Ratings

Positive Supply Voltage...................................................................................................................-0.3V ≤ V

Input Current ................................................................................................................................................± 25 mA

DD

≤ 7V

Digital Input Voltage .....................................................................................................V

- 0.3V ≤ VIN ≤ VDD + 0.3V

SS

Electrostatic Discharge (HBM)........................................................................................................................±500V

Storage Temperature......................................................................................................................-65°C to +125°C

Recommended Operating Conditions

Supply Voltage ..............................................................................................................................2.5V ≤ VDD ≤ 5.5V

Oscillator Frequency ...............................................................................................................................32.768 kHz

Operating Temperature....................................................................................................................- 25°C to +70°C

DC Characteristics (Default conditions: recommended operating conditions; outputs unloaded; VDD = 3.0V)
Symbol Parameter Conditions Min Typ Max Units

Test circuit fig. 5
I
I

DD0

DD

Standby Current no clock running 1.5 µA
Operating Current T

= 5 to 55 °C3050µA

AMB

Note 1, note 2
V

IL

V

IH

V

LCD

R

BIAS

Note 1: Segment and backplane outputs loaded with maximum 30 pF, power consumption of external voltage divider not

Note 2: Xtal parameters: Rimax = 60 kΩ (Rityp = 30 kΩ)

Input Voltage, Low V

SS

Line Voltage, High 0.8 V
Output Voltage, Sink I

= 4.8 mA 0.4 V

LCD

DD

0.2 V
V

Oscillator Bias Resistor 2.2 MΩ

included, R

= 2.2 MΩ ± 10%.

BIAS

Qmin = 35 000
Co = 1.5 pF (capacitance across Xtal terminals)
fxtal = 32.768 kHz

DD

DD

V
V

Rev. 1

7

Dec. 1993

Data Sheet

AS2590

AC Characteristics (VDD = 3.0V; T

= -25 to 70 °C, unless otherwise specified)

AMB

Symbol Parameter Conditions Min Typ Max Units

SDA/SCL Serial Interface Fig. 5
f

CL

f

CLH

f

CLL

f

CD

f

SOH

f

SOL

f

HD

f

SUSO

f

HSA

f

GAP

Clock Frequency 10 kHz
Clock High Time 50 µs
Clock Low Time 50 µs
Clock Low to Data Change 20 t

CLL

ns
Stop Bit High Time 50 µs
Stop Bit Low Time 50 µs
Data Hold Time 200 ns
Clock Setup for Stop 200 ns
Clock Hold for Start 200 ns
Data High between 2 Words 100 µs

BP0…3 Back Plane Outputs Figure 6, note 1
t

BRON

t

BFON

t

BROF

t

BFOF

t

BC

Rise Time, on 20 µs
Fall Time, on 20 µs
Rise Time, off 20 µs
Fall Time, off 20 µs
Cycle Frequency 128 Hz

S0…32 Segment Outputs Figure 7, note 2
t

SRON

t

SFON

t

SROF

t

SFOF

t

SC

t

TIMER

t

XUP

Rise Time, on 20 µs
Fall Time, on 20 µs
Rise Time, off 20 µs
Fall Time, off 20 µs
Cycle Frequency 128 Hz

Timer Display Time Note 3 5 6 sec

Oscillator Startup Time R

= 2.2 MΩ 300 ms

BIAS

Note 1: Loads on backplanes = 3 000 pF//10 MΩ
Note 2: Loads on segments = 360 pF//1 MΩ
Note 3: After BLANK ALL command and timer has been started with a valid start command, timer content is displayed.

Rev. 1

8

Dec. 1993

Data Sheet

Timing Diagrammes

t

HSA

SDA

SCL

t

CD

t

CLL

t

CLH

t

AS2590

HD

SDA

SCL

START

t

BIT 4

CLL

BIT 0

t

SUSO

t

SOH

t

SOL

STOP WORD GAP…

Figure 5 Serial Interface timing waveforms

t

GAP

BIT 1 …

Rev. 1

9

Dec. 1993

Data Sheet

Output Waveforms

AS2590

tBC

VDD

0.9 VDD

0.1 VDD
Vss

VDD

0.9 VDD

0.1 VDD
Vss

tBRON

tBFON

tBC

tBROF tBROF

Figure 6 Backplane timing waveforms

tSC

tSFON tSRON tSC

tSFOF tSFOF

Figure 7 Segment timing waveforms

Rev. 1

10

Dec. 1993

Data Sheet

Pin Configurations

AS2590

48 Pin DIP

BP1
BP0

S0
S1
S2
S3
S4

S5
S6

S7

S8

S9

V1/3

S10

148
2
3
4
5
6

7
8
9
10
11
12

13
14

47
46
45
44
43
42
41
40
39
38
37
36

AS2590

35

VDD
MS
XTAL2
XTAL1

BIAS

V
SCL

SDA

LCD

V
S20

S21
S22
S23
S24

S25

52 pin PLCC

S4
S5
S6
S7
S8
S9

V1/3

S10
S11
S12
S13
S14

NC

14

NCS3S2S1S0

BP0

BP1

1

VDDMS

XTAL2

XTAL1

AS2590

27

SS

S15

S16

S17

S18

S19

V

BP3

BP2

S32

V2/3

S31

BIAS

V

40

S30

SCL

NC

NC
SDA
V

LCD

S20
S21
S22
S23
S24
S25
S26
S27
S28
S29

S11
S12
S13
S14
S15
S16
S17
S18
S19

Vss

15
16
17
18
19
20
21
22
23

34
33
32
31

30

29
28
27
26

24 25

S26
S27
S28
S29
S30
S31
S32
V2/3
BP2
BP3

Ordering Information:

48 pin DIP: AS2590 P
52 pin PLCC: AS2590 N

Applications:

For application support contact your local AMS sales
offices.

Rev. 1

11

Dec. 1993

Data Sheet

AS2590

Sales Representative

Devices sold by Austria Mikro Systeme are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. Austria Mikro Systeme makes no warranty, express, statutory,
implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Austria Mikro Systeme reserves the right to change
specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with Austria Mikro Systeme for current information. This product
is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical
life-support or life-sustaining equipment are specifically

Copyright  1993, Austria Mikro Systeme International AG, Schloss Premstätten, 8141 Unterpremstätten, Austria. Trademarks Registered . All rights reserved. The material herein may not be
reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner.

The information furnished here by Austria Mikro Systeme is believed to be correct and accurate. However, Austria Mikro Systeme shall not be liable to recipient or any third party for any damages,
including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection
with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of Austria Mikro Systeme rendering
of technical or other services.

Rev. 1

not

recommended without additional processing by Austria Mikro Systeme for each application.

12

Dec. 1993