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Revision 2.24

16 - 20

AS1106, AS1107

8x8 LED Dot Matrix Driver

The application example in Figure 14 shows the AS1106 as an 8x8 LED dot matrix driver.

The LED columns have common cathodes 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 listed

in Table 7 on page 9.

The Decode Enable Register (see page 10) must be set to ‘00000000’ as described in Table 9 on page 10. Single

LEDs in a column can be addressed as described in Table 12 on page 11, where bit D0 corresponds to segment G and

bit D7 corresponds to segment DP.

Note: For a multiple-digit dot matrix, multiple AS1106 devices must be cascaded.

Figure 14. Application Example as LED Dot Matrix Driver

Cascading Drivers

The example in Figure 4 drives 2 dot matrix digits using a 4-wire microprocessor interface. All Scan-Limit Registers

should be set to the same value so that one display will not appear brighter than the other.

For example, to display 12 digits, set both Scan-Limit Registers to display 6 digits so that both displays have a 1/6 duty

cycle per digit. If 11 digits are needed, set both Scan-Limit Registers to display 6 digits and leave one digit uncon-

nected. Otherwise, if one driver is set to display 6 digits and the other to display 5 digits one display will appear brighter

because its duty cycle per digit will be 1/5 and the other display’s duty cycle will be 1/6.

Note: Refer to No-Op Register (0xX0) on page 13 for additional information.

SEG G

DIG0:7

DIN

GND

GND

LOAD/CSN

CLK

SEG A:G

SEG DP

9.53k

Ω

DIG0:7

DIN

GND

GND

LOAD/CSN

CLK

SEG A:G

SEG DP

9.53k

Ω

DOUT

8x8 LED Dot Matrix

8x8 LED Dot Matrix

Diode Arrangement

Micro-

Processor

SEG A

SEG DP

SEG B

SEG C

SEG D

SEG E

SEG F

SEG G

SEG A

SEG DP

SEG B

SEG C

SEG D

SEG E

SEG F