Data sheet
A S 11 0 0
Serially Interfaced, 8-Digit LED Driver
1 General Description
The AS1100 is an LED driver for 7 segment numeric
displays of up to 8 digits. The AS1100 can be
programmed via a conventional 4 wire serial interface.
The device includes a BCD code-B decoder, a multiplex
scan circuitry, segment and display drivers, and a 64 Bit
memory. The memory is used to store the LED settings,
so that continuous reprogramming is not necessary.
Every individual segment can be addressed and
updated separately. Only one external resistor is
required to set the current through the LED display.
Brightness can be controlled either in an analog or
digital way. The user can choose the internal code-B
decoder to display numeric digits or to address each
segment directly.
The AS1100 features an extremely low shutdown
current of only 20µA and an operational current of less
than 500µA. The number of visible digits can be
programmed as well. The AS1100 can be reset by
software and an external clock can be used. Several test
modes support easy debugging.
The AS1100 is offered in a 24-pin DIP and SOIC
packages.
2 Key Features
!
!
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!
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10MHz Serial Interface
Individual LED Segment Control
Decode/No-Decode Digit Selection
20µA Low-Power Shutdown (Data Retained)
Extremely low Operating Current 0.5mA in open
loop
Digital and Analog Brightness Control
Display Blanked on Power-Up
Drive Common-Cathode LED Display
Software Reset
Optional External clock
24-pin DIP and SOIC Packages
!
!
!
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3 Applications
The AS1100 is an ideal solution for Bar-Graph Displays,
Industrial Controllers, Panel Meters, LED Matrix
Displays and White Goods such as washing machines
and dishwasher.
Figure 1. AS1100 - Typical Application Diagram
9.53k
18
MOSI
µP I/O
SCK
+5V
19
VDD
ISET
DIFG0-DIG3
8 Digits
1 DIN
12 LOAD
1 CLK
9 GND
AS1100
SEG A-G
SEP DP
GND
4
8 Segments
8-Digit µP Display
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AS1100
Datasheet - P i n A s s i g n m e n t s
4 Pin Assignments
Figure 2. Pin Assignments (Top View)
DIN
1
24
DOUT
23
SEG D
22
SEG DP
21
SEG E
20
SEG C
19
VDD
18 I
SET
17
SEG G
16
SEG B
15
SEG F
14
SEG A
13
CLK
DIP/SO
DIG0
2
DIG4
3
GND
4
DIG6
5
DIG2
6
DIG3
7
DIG7
8
GND
9
DIG5
10
DIG1
11
LOAD
12
AS1100
Pin Descriptions
Table 1. Pin Descriptions
Pin Number
1
2, 3, 5:8, 10, 11
4, 9
12
Pin Name
DIN
DIG 0 : DIG 7
GND
LOAD/CS
Description
Data input.
Data is programmed into the 16Bit shift register on the rising
CLK edge
8 digit driver lines that sink the current from the common cathode of the
display. In shutdown mode the AS1100 switches the outputs to V
DD
.
Both GND pins must be connected.
Strobe input.
With the rising edge of the LOAD signal the 16 bit of serial
data is latched into the register.
Clock input.
The interface is capable to support clock frequencies up to
10MHz. The serial data is clocked into the internal shift register with the
rising edge of the CLK signal. On the DOUT pin the data is applied with the
falling edge of CLK.
Seven segment driver lines including the decimal point.
When a
segment is turned off the output is connected to GND.
The current into ISET determines the peak current through the segments
and therefore the brightness.
Positive Supply Voltage
(+5V)
Serial data output for cascading drivers.
The output is valid after 16.5
clock cycles. The output is never set to high impedance.
13
CLK
14:17, 20:23
18
19
24
SEGA:G, DP
ISET
VDD
DOUT
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AS1100
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Table 2. Absolute Maximum Ratings
Parameter
VDD to GND
DIN, CLK, LOAD to GND
All other Pins to GND
V
OUT
Electro Static Discharge at Digital
Outputs
Electro Static Discharge at all other pins
Current
DIG0–DIG7 Sink Current
SEGA–G, DP Source Current
Latch up Immunity
Continuous Power Dissipation (TA = +85°C)
Narrow Plastic DIP
Wide SO
Operating Temperature Ranges (T
MIN
to T
MAX
)
AS1100xL
AS1100xE
Storage Temperature Range
0
-40
-65
+70
+85
+150
ºC
ºC
ºC
The reflow peak soldering temperature
(body temperature) specified is in
accordance with
IPC/JEDEC J-STD-
020D “Moisture/Reflow Sensitivity
Classification for Non-Hermetic Solid
State Surface Mount Devices”.
The lead finish for Pb-free leaded
packages is matte tin (100% Sn).
1066
941
mW
mW
Derate 13.3mW/°C above +70°C
Derate 11.8mW/°C above +70°C
500
100
±200
mA
mA
mA
Min
-0.3
-0.3
-0.3
-0.3
+500
+1000
Max
+6
+6
V
DD
+ 0.3
7
Units
V
V
V
V
V
V
Notes
Package Body Temperature
+260
ºC
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AS1100
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
V
DD
= 5V, R
SET
= 9.53kΩ±1%, T
A
= T
MIN
to T
MAX
, unlesss otherwise noted.
Table 3. Electrical Characteristics
Symbol
V
DD
I
DDSD
Parameter
Operating Supply Voltage
Shutdown Supply Current
All digital inputs at V
DD
or GND,
TA = +25ºC
R
SET
= open circuit
I
DD
f
OSC
I
DIGIT
I
SEG
ΔI
SEG
I
DIGIT
I
SEG
I
IH
, I
IL
V
IH
V
IL
V
OH
V
OL
Operating Supply Current
Display Scan Rate
Digit Drive Sink Current
Segment Drive Source Current
Segment Drive Current
Matching
Digit Drive Source Current
Segment Drive Sink Current
Digit off, V
DIGIT
= (V
DD
-0.3V)
Segment off, V
SEG
= 0.3V
-2
5
All segments and decimal point on,
I
SEG
= -40mA
8 digits scanned
V
OUT
= 0.65V
T
A
= +25ºC, V
OUT
= (V
DD
-1V)
500
320
-30
-40
3.0
-45
330
800
1300
Conditions
Min
4.0
Typ
5.0
20
Max
5.5
50
500
Units
V
µA
µA
mA
Hz
mA
mA
%
mA
mA
Logic Inputs
Input Current DIN, CLK, LOAD
Logic High Input Voltage
Logic Low Input Voltage
Output High Voltage
Output Low Voltage
Hysteresis Voltage
Timing Characteristics
t
CP
t
CH
t
CL
t
CSH
t
DS
t
DH
t
DO
t
LDCK
t
CSW
t
DSPD
CLK Clock Period
CLK Pulse Width High
CLK Pulse Width Low
CLK Rise to LOAD Rise Hold
Time
DIN Setup Time
DIN Hold Time
Output Data Propagation Delay
LOAD Rising Edge to Next
Clock Rising Edge
Minimum LOAD Pulse High
Data-to-Segment Delay
C
LOAD
= 50pF
50
50
2.25
100
50
50
0
25
0
25
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
DOUT, I
SOURCE
= -1mA
DOUT, I
SINK
= 1.6mA
DIN, CLK, LOAD
1
V
DD
- 1
0.4
V
IN
= 0V or V
DD
-1
3.5
0.8
1
µA
V
V
V
V
V
Note:
All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or
SQC (Statistical Quality Control) methods.
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AS1100
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
Figure 3. Segment Driver Capability,
V
DD
= 5V, Logic Level = High
50
45
Figure 4. Segment Current versa R
SET
50
45
40
Segment Current (mA)
.
40
35
30
25
20
15
10
5
0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
ISEGMENT (mA)
.
35
30
25
20
15
10
5
0
10
100
Voltage below VDD at output (V)
RSET (kOhm)
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