AS1105 datasheet(9/12 Pages) AMSCO

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Data Sheet AS1105

Revision 1.32, Oct. 2004

Page 9 of 12

4x8 LED Dot Matrix Driver

The example in Figure 3 uses the AS1105 to drive an 4x8 LED dot matrix. The LED columns have common cathode

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 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

AS1105 have to be cascaded.

Cascading Drivers

The AS1105 can be cascaded as well. The DOUT pin must be connected to the DIN pin of the following AS1105.

Package

Thermal Resistance (

θθθθJA)

20 Wide SO

+85°C/W

Maximum Junction Temperature (TJ) = +150°C

Maximum Ambient Temperature (TA) = +85°C

Table 13: Package thermal resistance data

Figure 3: Application example as LED dot matrix driver

µP

DIG 3

4x8 LED Dot

Mt i

9.53k

VBAT

LOA

CLK

GND GND

DIG 0-3

SEG A-G

SEP DP

VDD

ISET

DIN

DIG 0

SEG B

SEG A

SEG DP

SEG E

SEG D

SEG C

SEG F

SEG G