AS1105WL austriamicrosystems, AS1105WL Datasheet - Page 11

• 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 - A p p l i c a t i o n I n f o r m a t i o n
9 Application Information
Supply Bypassing and Wiring
In order to achieve optimal performance the AS1105 shall be placed very close to the LED display to minimize effects
of electromagnetic interference and wiring inductance. Furthermore, it is recommended to connect a 10µF electrolytic
and a 0.1µF ceramic capacitor between V
connected to ground.
Selecting R
The current through the segments is controlled via the external resistor R
current in I
higher currents are needed, external drivers must be used. In that case it is no longer necessary that the AS1105
drives high currents. A recommended value for R
specifies the maximum currents and R
acceptable limits for ambient temperature, segment current, and the LED forward-voltage drop.
4x8 LED Dot Matrix Driver
The example in
and are connected to the DIG0-3 outputs. The rows are connected to the segment drivers. Each of the 32 LEDs can be
addressed separately. The columns are selected via the digits as shown in
has to be programmed to ‘00000000’ as stated in
Table
have to be cascaded.
Figure 7. Application example as LED dot matrix driver
www.austriamicrosystems.com
Diode Arrangement
10, where D0 corresponds to segment G and D7 to segment DP. For a multiple digit dot matrix several AS1105
SET
µP
. The right values for I
Figure 7
SET
Resistor and Using External Drivers
12
1
1
9
uses the AS1105 to drive an 4x8 LED dot matrix. The LED columns have common cathode
SEG A-G DIG 0-3
CLK
DIN
GND
LOA
SEG DP
SEG G
SEG F
SEG E
SEG D
SEG C
SEG B
SEG A
GND
DIG 0
SET
DOUT
SET
are given in
ISET
VDD
DD
must be set accordingly. Refer to Absolute Maximum Ratings to calculate
4x8 LED Dot
and GND to avoid power supply ripple. Also, both GNDs must be
19
18
SET
Table
Table
Revision 1.34
is 47kΩ. In cases that the AS1105 only drives few digits
9.53k
VBAT
DIG 3
7. The single LEDs in a column can be addressed as stated in
12. The maximum current the AS1105 can drive is 40mA. If
12
1
9
1
SET
SEG A-G DIG 0-3
Table
DIN
CLK
GND
LOA
. Segment current is about 100 times the
SEG DP
SEG G
SEG F
SEG E
SEG A
SEG D
SEG C
SEG B
GND
5. The decode mode register (0xX9)
DIG 0
DOUT
ISET
VDD
4x8 LED Dot
19
18
9.53k
VBAT
DIG 3
Table 10
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