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Revision 2.13

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AS1108

Datasheet - P i n o u t

4 Pinout

Pin Assignments

Figure 2. Pin Assignments (Top View)

Pin Descriptions

Table 1. Pin Descriptions

Pin Number

Pin Name

Description

1

DOUT

Serial-Data Output. The data into pin DIN is valid at pin DOUT 16.5 clock

cycles later. This pin is used to daisy-chain several AS1108 devices and is

never high-impedance.

2

DIN

Serial-Data Input. Data is loaded into the internal 16-bit shift register on the

rising edge of pin CLK.

3, 5, 6, 8

DIG 0:DIG 3

Digit Drive Lines. 4 four-digit drive lines that sink current from the display

common cathode. The AS1108 pulls the digit outputs to VDD when turned off.

4, 7

GND

Ground. Both GND pins must be connected.

9

LOAD/CSN

Load-Data Input. The last 16 bits of serial data are latched on the rising edge

of this pin.

Chip-Select Input (AS1108 SPI-enabled only). Serial data is loaded into the

shift register while this pin is low. The last 16 bits of serial data are latched on

the rising edge of this pin.

10

CLK

Serial-Clock Input. 10MHz maximum rate. Data is shifted into the internal

shift register on the rising edge of this pin. Data is clocked out of DOUT on the

falling edge of this pin. On the AS1108 SPI-enabled, the CLK input is active

only while pin LOAD/CSN is low.

11, 12, 13, 14,

17, 18, 19, 20

SEG A:SEG G,

SEG DP

Seven Segment and Decimal Point Drive Lines. 8 seven-segment drives

and decimal point drive that source current to the display. When a segment

driver is turned off it is pulled to GND.

15

ISET

Set Segment Current. Connect to VDD through RSET to set the peak segment

current (see Selecting RSET Resistor Value and Using External Drivers on

page 14).

16

VDD

Positive Supply Voltage. Connect to +2.7 to +5.5V supply.

20

19

18

17

16

15

14

13

12

11

1

2

3

4

5

6

7

8

9

10

SEG D

SEG DP

SEG E

SEG C

VDD

ISET

SEG G

SEG B

SEG F

SEG A

DOUT

DIN

DIG 0

GND

DIG 2

DIG 3

GND

DIG 1

LOAD/CSN

CLK

AS1108