AS1108
Datasheet - Pinout
4 Pinout
Pin Assignments
Figure 2. Pin Assignments (Top View)
DOUT
DIN
SEG D
SEG DP
SEG E
SEG C
VDD
1
2
3
4
5
6
7
8
9
20
19
18
17
16
15
14
DIG 0
GND
DIG 2
AS1108
DIG 3
ISET
GND
SEG G
DIG 1
13 SEG B
12 SEG F
11 SEG A
LOAD/CSN
CLK 10
Pin Descriptions
Table 1. Pin Descriptions
Pin Number
Pin Name
Description
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.
1
DOUT
Serial-Data Input. Data is loaded into the internal 16-bit shift register on the
rising edge of pin CLK.
2
DIN
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.
3, 5, 6, 8
4, 7
DIG 0:DIG 3
GND
Ground. Both GND pins must be connected.
Load-Data Input. The last 16 bits of serial data are latched on the rising edge
of this pin.
9
LOAD/CSN
CLK
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.
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.
10
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.
11, 12, 13, 14,
17, 18, 19, 20
SEG A:SEG G,
SEG DP
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).
15
16
ISET
VDD
Positive Supply Voltage. Connect to +2.7 to +5.5V supply.
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