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REV. B
AD7890
–6–
Pin
Mnemonic
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
μ
F disc ceramic capacitor. The output impedance of this reference source is typically
2 k
. When using an external reference source as the reference voltage for the part, the reference
source should be connected to this pin. This overdrives the internal reference and provides the refer-
ence 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.
17
V
IN2
18
V
IN3
19
V
IN4
20
V
IN5
21
V
IN6
22
V
IN7
23
V
IN8
24
REF OUT/REF IN
PIN CONFIGURATION
DIP and SOIC
TOP VIEW
(Not to Scale)
24
23
22
21
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
9
10
11
12
AD7890
AGND
REF OUT/REF IN
SMODE
V
IN8
DGND
V
IN7
V
IN6
V
IN5
V
IN4
V
IN3
V
IN2
V
IN1
AGND
C
EXT
CONVST
CLK IN
SCLK
TFS
RFS
DATA OUT
DATA IN
SHA IN
V
DD
MUX OUT