AD5303/AD5313/AD5323
Rev. B | Page 9 of 28
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
1
2
3
4
5
6
7
8
LDAC
V
DD
V
REF
B
BUF A
OUT
A
V
REF
A
CLR
BUF B
16
15
14
13
12
11
10
9
GND
DIN
SCLK
PD
DCEN
V
OUT
B
SYNC
SDO
AD5303/
AD5313/
AD5323
TOP VIEW
(Not to Scale)
00472-004
Figure 6. Pin Configuration
Table 5. Pin Function Descriptions
Pin No. Mnemonic Description
1
CLR
Active Low Control Input. Loads all zeros to both input and DAC registers.
2
LDAC Active Low Control Input. Transfers the contents of the input registers to their respective DAC registers. Pulsing
this pin low allows either or both DAC registers to be updated if the input registers have new data. This allows
the simultaneous update of both DAC outputs.
3 V
DD
Power Supply Input. These parts can be operated from 2.5 V to 5.5 V, and the supply should be decoupled to GND.
4 V
REF
B
Reference Input Pin for DAC B. It may be configured as a buffered or an unbuffered input, depending on the state
of the BUF B pin. It has an input range from 0 V to V
DD
in unbuffered mode and from 1 V to V
DD
in buffered mode.
5 V
REF
A
Reference Input Pin for DAC A. It may be configured as a buffered or an unbuffered input depending on the state
of the BUF A pin. It has an input range from 0 to V
DD
in unbuffered mode and from 1 V to V
DD
in buffered mode.
6 V
OUT
A Buffered Analog Output Voltage from DAC A. The output amplifier has rail-to-rail operation.
7 BUF A
Control Pin. Controls whether the reference input for DAC A is unbuffered or buffered. If this pin is tied low, the
reference input is unbuffered. If it is tied high, the reference input is buffered.
8 BUF B
Control Pin. Controls whether the reference input for DAC B is unbuffered or buffered. If this pin is tied low, the
reference input is unbuffered. If it is tied high, the reference input is buffered.
9 DCEN
This pin is used to enable the daisy-chaining option. This should be tied high if the part is being used in a daisy
chain. The pin should be tied low if it is being used in standalone mode.
10
PD Active Low Control Input. Acts as a hardware power-down option. This pin overrides any software power-down
option. Both DACs go into power-down mode when this pin is tied low. The DAC outputs go into a high
impedance state and the current consumption of the part drops to 200 nA @ 5 V (50 nA @ 3 V).
11 V
OUT
B Buffered Analog Output Voltage from DAC B. The output amplifier has rail-to-rail operation.
12
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.
13 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.
14 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.
15 GND Ground Reference Point for All Circuitry on the Part.
16 SDO
Serial Data Output. Can be used for daisy-chaining a number of these devices together or for reading back the
data in the shift register for diagnostic purposes. The serial data output is valid on the falling edge of the clock.
