AS1105WL austriamicrosystems, AS1105WL Datasheet - Page 10

• Manufacturer Part Number: AS1105WL
• Description: IC LED 4-DIGIT DRIVER 20-SOIC
• Manufacturer: austriamicrosystems

Specifications of AS1105WL

• Display Type: LED
• Configuration: 7 Segment + DP
• Interface: Serial
• Digits Or Characters: 4 Digits
• Current - Supply: 330mA
• Voltage - Supply: 4 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-SOIC (0.300", 7.50mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AS1105
Data Sheet - D e t a i l e d D e s c r i p t i o n
Display Test Register
With the display test register 0Fh all LED can be tested. In the test mode all LEDs are switched on at maximum
brightness (duty cycle 31/32). All programming of digit and control registers is maintained. The format of the register is
given in
Table 12. Maximum segment current for 1-, 2-, or 3-digit displays
Table 13. Display-test register format (address (hex) = 0xXF)
Note: The AS1105 remains in display-test mode until the display-test register is reconfigured for normal operation.
No-Op Register (Cascading of AS1105)
The no-operation register 00h is used when AS1105s are cascaded in order to support more than 4 digit displays. The
cascading must be done in a way that all DOUT are connected to DIN of the following AS1105. The LOAD and CLK
signals are connected to all devices. For a write operation for example to the fifth device the command must be
followed by four no-operation commands. When the LOAD signal finally goes to high all shift registers are latched. The
first four devices have got no-operation commands and only the fifth device sees the intended command and updates
its register.
Reset and external Clock Register
This register is addressed via the serial interface. It allows to switch the device to external clock mode (If D0=1 the
CLK pin of the serial interface operates as system clock input.) and to apply an external reset (D1). This brings all
registers (except reg. E) to default state. For standard operation the register contents should be "00h".
Table 14. Reset and external Clock register (address (hex) = 0xXE)
Table 15. R
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Normal Operation, external clock
Normal Operation, internal clock
Display Test Mode
Normal Operation
Reset state, external clock
I
Reset state, internal clock
SEG
Table
40
30
20
10
Mode
(mA)
Number of Digits Displayed
SET
13.
Mode
vs. segment current and LED forward voltage
1
2
3
12.2kΩ
17.8kΩ
29.8kΩ
66.7kΩ
1.5
D7
X
X
Address Code
D6
0xXE
(hex)
0xXE
0xXE
0xXE
X
X
17.1kΩ
28.0kΩ
63.7kΩ
11.8kΩ
2.0
Revision 1.34
D5
X
X
D7
X
X
X
X
D6
X
X
X
X
Register Data
D4
V
X
X
11.0kΩ
15.8kΩ
25.9kΩ
59.3kΩ
LED
2.5
Maximum Segment Current (mA)
(V)
D5
X
X
X
X
D3
X
X
Register Data
D4
X
X
X
X
10
20
30
10.6kΩ
15.0kΩ
24.5kΩ
55.4kΩ
3.0
D2
X
X
D3
X
X
X
X
D2
X
X
X
X
D1
X
X
D1
0
0
1
1
9.69kΩ
14.0kΩ
22.6kΩ
51.2kΩ
3.5
D0
10 - 15
0
1
D0
0
1
0
1