Datasheet

AD7564
REV. B –7–
PIN DESCRIPTIONS
Pin
Number Mnemonic Description
1 DGND Digital Ground.
2 I
OUT2
C I
OUT2
terminal for DAC C. This should normally connect to the signal ground of the system.
3 V
DD
Positive power supply. This is +5 V ± 5%.
4 I
OUT1
C I
OUT1
terminal for DAC C.
5 R
FB
C Feedback resistor for DAC C.
6 V
REF
C DAC C reference input.
7 I
OUT2
D I
OUT2
terminal for DAC D. This should normally connect to the signal ground of the system.
8 I
OUT1
D I
OUT1
terminal for DAC D.
9 R
FB
D Feedback resistor for DAC D.
10 V
REF
D DAC D reference input.
11 SDOUT This shift register output allows multiple devices to be connected in a daisy chain configuration.
12
CLR
Asynchronous CLR input. When this input is taken low, all DAC latches are loaded with all 0s.
13
LDAC
Asynchronous LDAC input. When this input is taken low, all DAC latches are simultaneously updated with the
contents of the input latches.
14
FSIN
Level-triggered control input (active low). This is the frame synchronization signal for the input data. When FSIN
goes low, it enables the input shift register, and data is transferred on the falling edges of CLKIN. If the address
bits are valid, the 12-bit DAC data is transferred to the appropriate input latch on the sixteenth falling edge after
FSIN
goes low.
15 SDIN
Serial data input. The device accepts a 16-bit word. DB0 and DB1 are DAC select bits. DB2 and DB3 are device
address bits. DB4 to DB15 contain the 12-bit data to be loaded to the selected DAC.
16 CLKIN
Clock Input. Data is clocked into the input shift register on the falling edges of CLKIN. Add a pull-down resistor on
the clock line to avoid timing issues.
17 A1
Device address pin. This input in association with A0 gives the device an address. If DB2 and DB3 of the serial
input stream do not correspond to this address, the data which follows is ignored and not loaded to any input
latch. However, it will appear at SDOUT irrespective of this.
18 A0 Device address pin. This input in association with A1 gives the device an address.
19 V
REF
A DAC A reference input.
20 R
FB
A Feedback resistor for DAC A.
21 I
OUT1
A I
OUT1
terminal for DAC A.
22 I
OUT2
A I
OUT2
terminal for DAC A. This should normally connect to the signal ground of the system.
23 V
REFB
DAC B reference input.
24 R
FB
B Feedback resistor for DAC B.
25 I
OUT1
B I
OUT1
terminal for DAC B.
26 N/C No Connect pin.
27 AGND
This pin connects to the back gates of the current steering switches. It should be connected to the signal ground
of the system.
28 I
OUT2
B I
OUT2
terminal for DAC B. This should normally connect to the signal ground of the system.