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Revision 2.1

15 - 19

AS1108

Data Sheet

Pin Assignments

9 Pinout and Packaging

Pin Assignments

Figure 12. DIP and SO Pin Assignments (Top View)

Pin Descriptions

Table 24. Pin Descriptions

Pin

Name

Pin

Number

Description

DOUT

1

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.

DIN

2

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

rising edge of pin CLK.

DIG 0:DIG 3

3, 5, 6, 8

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

off.

GND

4, 7

Ground. Both GND pins must be connected.

LOAD/CSN

9

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.

CLK

10

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.

SEG A:SEG G, SEG DP

11, 12, 13,

14, 17, 18,

19, 20

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

segment current (see Selecting RSET Resistor Value and Using External

Drivers on page 12).

16

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

SEG G

SEG B

SEG F

SEG A

DOUT

DIN

DIG 0

GND

DIG 2

DIG 3

GND

DIG 1

LOAD/CSN

CLK

AS1108