AD5308/AD5318/AD5328
PIN CONFIGURATION
LDAC
SYNC
16 SCLK
15 DIN
1
2
3
4
5
6
7
8
AD5308/
AD5318/
AD5328
TOP VIEW
(Not to Scale)
V
14 GND
DD
V
V
V
V
V
H
G
F
V
A
B
C
D
13
12
11
10
9
OUT
OUT
OUT
OUT
OUT
OUT
OUT
OUT
V
V
V
E
EFGH
REF
V
ABCD
REF
PIN FUNCTION DESCRIPTIONS
Pin No. Mnemonic
Function
1
LDAC
This active low-control input transfers the contents of the input registers to their respective DAC registers.
Pulsing this pin low allows any or all DAC registers to be updated if the input registers have new data.
This allows simultaneous update of all DAC outputs. Alternatively, this pin can be tied permanently low.
2
SYNC
Active Low-Control Input. This is the frame synchronization signal for the input data. When SYNC goes
low, it powers on the SCLK and DIN buffers and enables the input shift register. Data is transferred in
on the falling edges of the following 16 clocks. If SYNC is taken high before the 16th falling edge, the
rising edge of SYNC acts as an interrupt and the write sequence is ignored by the device.
3
VDD
Power Supply Input. These parts can be operated from 2.5 V to 5.5 V, and the supply should be
decoupled with a 10 µF capacitor in parallel with a 0.1 µF capacitor to GND.
4
5
6
7
8
V
V
V
V
V
OUTA
Buffered Analog Output Voltage from DAC A. The output amplifier has rail-to-rail operation.
Buffered Analog Output Voltage from DAC B. The output amplifier has rail-to-rail operation.
Buffered Analog Output Voltage from DAC C. The output amplifier has rail-to-rail operation.
Buffered Analog Output Voltage from DAC D. The output amplifier has rail-to-rail operation.
OUTB
OUTC
OUTD
REFABCD
Reference Input Pin for DACs A, B, C, and D. It may be configured as a buffered, unbuffered, or VDD
input to the four DACs, depending on the state of the BUF and VDD control bits. It has an input range
from 0.25 V to VDD in unbuffered mode and from 1 V to VDD in buffered mode.
9
V
REFEFGH
Reference Input Pin for DACs E, F, G, and H. It may be configured as a buffered, unbuffered, or VDD
input to the four DACs, depending on the state of the BUF and VDD control bits. It has an input range
from 0.25 V to VDD in unbuffered mode and from 1 V to VDD in buffered mode.
10
11
12
13
14
15
V
V
V
V
OUTE
OUTF
OUTG
OUTH
Buffered Analog Output Voltage from DAC E. The output amplifier has rail-to-rail operation.
Buffered Analog Output Voltage from DAC F. The output amplifier has rail-to-rail operation.
Buffered Analog Output Voltage from DAC G. The output amplifier has rail-to-rail operation.
Buffered Analog Output Voltage from DAC H. The output amplifier has rail-to-rail operation.
Ground Reference Point for All Circuitry on the Part.
GND
DIN
Serial Data Input. This device has a 16-bit shift register. Data is clocked into the register on the falling
edge of the serial clock input. The DIN input buffer is powered down after each write cycle.
16
SCLK
Serial Clock Input. Data is clocked into the input shift register on the falling edge of the serial clock
input. Data can be transferred at rates up to 30 MHz. The SCLK input buffer is powered down after
each write cycle.
REV. B
–5–