Datasheet

AD5174
Rev. B | Page 7 of 20
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
V
DD
1
1
V
SS
2
2
A
3
3
W
4
4
SDO
10
9
8
SCLK
7
5
EXT_CAP
DIN
6
GND
AD5174
TOP VIEW
(Not to Scale)
SYNC
08718-005
SYNC
V
DD
1
V
SS
2
A
3
W
4
SDO
10
9
8
SCLK
7
5
EXT_CAP
DIN
6
GND
*LEAVE FLOATING OR CONNECTED TO V
SS
.
AD5174
(EXPOSED
PAD)*
08718-103
Figure 5. MSOP Pin Configuration Figure 6. LFCSP Pin Configuration
Table 5. Pin Function Descriptions
Pin No. Mnemonic Description
1 V
DD
Positive Power Supply. Decouple this pin with 0.1 μF ceramic capacitors and 10 μF capacitors.
2 A Terminal A of RDAC. V
SS
≤ V
A
≤ V
DD
.
3 W Wiper Terminal of RDAC. V
SS
≤ V
W
≤ V
DD
.
4 V
SS
Negative Supply. Connect to 0 V for single-supply applications. Decouple this pin with 0.1 μF ceramic capacitors
and 10 μF capacitors.
5 EXT_CAP
External Capacitor. Connect a 1 μF capacitor between EXT_CAP and V
SS
. This capacitor must have a voltage
rating of ≥7 V.
6 GND Ground Pin, Logic Ground Reference.
7 SDO
Serial Data Output. This pin can be used to clock data from the shift register in daisy-chain mode or in readback
mode. This open-drain output requires an external pull-up resistor even if it is not use.
8 DIN
Serial Data Line. This pin is used in conjunction with the SCLK line to clock data into or out of the 16-bit
input register.
9 SCLK
Serial Clock Input. Data is clocked into the shift register on the falling edge of the serial clock input. Data can be
transferred at rates of up to 50 MHz.
10
SYNC
Falling Edge Synchronization Signal. This is the frame synchronization signal for the input data. When SYNC
goes low, it enables the shift register and data is transferred in on the falling edges of the subsequent clocks.
The selected register is updated on the rising edge of SYNC following the 16
th
clock cycle. If SYNC is taken
high before the 16
th
clock cycle, the rising edge of SYNC acts as an interrupt, and the write sequence is ignored
by the RDAC.
EPAD Exposed Pad Leave floating or connected to V
SS