AD1671
PIN DESCRIPTION
Type Name and Function
Symbol
Pin No.
ACOM
AIN
27
P
Analog Ground.
Analog Inputs, AIN1 and AIN2. The AD1671 can be pin strapped for four input ranges:
22, 23
AI
Range
Pin Strap
Signal Input
0 to +2.5 V, ±2.5 V
0 to +5 V, ±5 V
Connect AIN1 to AIN2
Connect AIN1 or AIN2 to ACOM
AIN1 or AIN2
AIN1 or AIN2
BIT 1 (MSB) 13
DO
DO
DO
AI
Most Significant Bit.
Data Bits 2 through 11.
Least Significant Bit.
BIT 2–BIT 11 12-3
BIT 12 (LSB)
BPO/UPO
DAV
2
26
16
Bipolar or Unipolar Configuration Pin. See section on Input Range Connections for details.
DO
Data Available Output. The rising edge of DAV indicates an end of conversion and can be used
to latch current data into an external register. The falling edge of DAV can be used to latch
previous dam into an external register.
DCOM
ENCODE
MSB
19
17
14
15
P
Digital Ground.
DI
DO
DO
The analog input is sampled on the rising edge of ENCODE.
Inverted Most Significant Bit. Provides twos complement output data format.
OTR
Out of Range is Active HIGH when the analog input is out of range. See Output Data Format,
Table III.
REF COM
20
AI
REF COM is the internal reference ground pin. REF COM should be connected as indicated
in the Grounding and Decoupling Rules and Optional External Reference Connection Sections.
REF IN
REF OUT
SHA OUT
VCC
24
21
25
28
1
AI
AO
AO
P
REF IN is the external 2.5 V reference input.
REF OUT is the internal 2.5 V reference output.
No Connect for bipolar input ranges. Connect SHA OUT to BPO/UPO for unipolar input ranges.
+5 V Analog Power.
VEE
P
–5 V Analog Power.
VLOGIC
18
P
+5 V Digital Power.
TYPE: AI = Analog Input; AO = Analog Output; DI = Digital Input; DO = Digital Outputs; P = Power.
PIN CONFIGURATION
V
V
1
28
27
26
25
24
23
22
21
20
EE
CC
BIT 12 (LSB)
BIT 11
ACOM
2
3
BPO/UPO
4
5
6
7
8
9
BIT 10
SHA OUT
REF IN
AIN1
BIT 9
BIT 8
AD1671
TOP VIEW
(Not to Scale)
BIT 7
BIT 6
BIT 5
AIN2
REF OUT
REF COM
BIT 4 10
11
19 DCOM
18
17
V
BIT 3
BIT 2 12
LOGIC
ENCODE
BIT 1 (MSB)
13
14
16 DAV
15
OTR
MSB
–4–
REV. B
ADI [ ADI ]
