AD7890
Pin
17
Mnemonic
V
IN2
Description
Analog Input Channel 2. Single-ended analog input. The analog input range on is
±
10 V (AD7890-
10), 0 V to +4.096 V (AD7890-4) and 0 V to +2.5 V (AD7890-2). The channel to be converted is
selected using the A0, A1 and A2 bits in the control register. The multiplexer has guaranteed
break-before-make operation.
Analog Input Channel 3. Single-ended analog input. The analog input range on is
±
10 V (AD7890-
10), 0 V to +4.096 V (AD7890-4) and 0 V to +2.5 V (AD7890-2). The channel to be converted is
selected using the A0, A1 and A2 bits in the control register. The multiplexer has guaranteed
break-before-make operation.
Analog Input Channel 4. Single-ended analog input. The analog input range on is
±
10 V (AD7890-
10), 0 V to +4.096 V (AD7890-4) and 0 V to +2.5 V (AD7890-2). The channel to be converted is
selected using the A0, A1 and A2 bits in the control register. The multiplexer has guaranteed
break-before-make operation.
Analog Input Channel 5. Single-ended analog input. The analog input range on is
±
10 V (AD7890-
10), 0 V to +4.096 V (AD7890-4) and 0 V to +2.5 V (AD7890-2). The channel to be converted is
selected using the A0, A1 and A2 bits in the control register. The multiplexer has guaranteed
break-before-make operation.
Analog Input Channel 6. Single-ended analog input. The analog input range on is
±
10 V (AD7890-
10), 0 V to +4.096 V (AD7890-4) and 0 V to +2.5 V (AD7890-2). The channel to be converted is
selected using the A0, A1 and A2 bits in the control register. The multiplexer has guaranteed
break-before-make operation.
Analog Input Channel 7. Single-ended analog input. The analog input range on is
±
10 V (AD7890-
10), 0 V to +4.096 V (AD7890-4) and 0 V to +2.5 V (AD7890-2). The channel to be converted is
selected using the A0, A1 and A2 bits in the control register. The multiplexer has guaranteed
break-before-make operation.
Analog Input Channel 8. Single-ended analog input. The analog input range on is
±
10 V (AD7890-
10), 0 V to +4.096 V (AD7890-4) and 0 V to +2.5 V (AD7890-2). The channel to be converted is
selected using the A0, A1 and A2 bits in the control register. The multiplexer has guaranteed
break-before-make operation.
Voltage Reference Output/Input. The part can be used with either its own internal reference or with
an external reference source. The on-chip +2.5 V reference voltage is provided at this pin. When
using this internal reference as the reference source for the part, REF OUT should decoupled to
AGND with a 0.1
µF
disc ceramic capacitor. The output impedance of this reference source is typi-
cally 2 kΩ. When using an external reference source as the reference voltage for the part, the refer-
ence source should be connected to this pin. This overdrives the internal reference and provides the
reference source for the part. The REF IN input is buffered on-chip. The nominal reference voltage
for correct operation of the AD7890 is +2.5 V.
PIN CONFIGURATION
DIP and SOIC
AGND
SMODE
DGND
C
EXT
CONVST
CLK IN
SCLK
TFS
RFS
1
2
3
4
5
6
7
8
9
24 REF OUT/REF IN
23 V
IN8
22 V
IN7
21 V
IN6
20 V
IN5
19
TOP VIEW
(Not to Scale) 18
18
V
IN3
19
V
IN4
20
V
IN5
21
V
IN6
22
V
IN7
23
V
IN8
24
REF OUT/REF IN
AD7890
V
IN4
V
IN3
17 V
IN2
16
V
IN1
DATA OUT 10
DATA IN
11
15 AGND
14
SHA IN
V
DD
12
13 MUX OUT
–6–
REV. A
AD [ ANALOG DEVICES ]
