Data Sheet AS1100
8x8 LED Dot Matrix Driver
The example in Figure 3 uses the AS1100 to drive an 8x8 LED dot matrix. The LED columns have common cathode
and are connected to the DIG0-7 outputs. The rows are connected to the segment drivers. Each of the 64 LEDs can
be addressed separately. The columns are selected via the digits as shown in Table 2. The decode mode register
(0xX9) has to be programmed to ‘00000000’ as stated in Table 4. The single LEDs in a column can be addressed as
stated in Table 6, where D0 corresponds to segment G and d/ to segment DP. For a multiple digit dot matrix several
AS1100 have to be cascaded.
Diode Arrangement
SEG G
SEG F
SEG E
SEG D
SEG C
SEG B
SEG A
SEG DP
DIG 0
8x8 LED Dot
M t i
SEG G
SEG F
SEG E
SEG D
SEG C
SEG B
SEG A
SEG DP
DIG 7
DIG 0
SEG A-G DIG 0-
SEP DP
1
12
DIN
LOA
CLK
GND GND
4
8x8 LED Dot
M t i
DIG 7
µP
SEG A-G DIG 0-
24
DOUT
SEP DP
19
1
VDD
DIN
12
LOA
1
CLK
18
9
GND GND ISET
4
VBAT
VDD
19
VBAT
9.53k
1
9
ISET
18
9.53k
Figure 3: Application example as LED dot matrix driver
Cascading Drivers
The AS1100 can be cascaded as well. The DOUT pin must be connected to the DIN pin of the following AS1100.
Thermal Resistance (θ
JA
)
θ
Package
24 Narrow DIP
+75°C/W
24 Wide SO
+85°C/W
Maximum Junction Temperature (T
J
) = +150°C
Maximum Ambient Temperature (T
A
) = +85°C
Table 13: Package thermal resistance data
Revision 1.32, Oct. 2004
Page 9 of 12
AMSCO [ AUSTRIAMICROSYSTEMS AG ]
