AD8223ARM Analog Devices Inc, AD8223ARM Datasheet - Page 17

• Manufacturer Part Number: AD8223ARM
• Description: Single Supply Low Cost Intrumentation Am
• Manufacturer: Analog Devices Inc

Specifications of AD8223ARM

• Amplifier Type: Instrumentation
• Number Of Circuits: 1
• Output Type: Rail-to-Rail
• Slew Rate: 0.3 V/µs
• -3db Bandwidth: 200kHz
• Current - Input Bias: 12nA
• Voltage - Input Offset: 250µV
• Current - Supply: 650µA
• Voltage - Supply, Single/dual (±): 3 V ~ 24 V, ±2 V ~ 12 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Peak Reflow Compatible (260 C): No
• Rohs Compliant: No
• Input Offset Voltage: 250µV
• Bandwidth: 200kHz
• Amplifier Output: Rail To Rail
• Cmrr: 90dB
• Supply Current: 350µA
• Amplifier Case Style: MSOP
• No. Of Pins: 8
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Output / Channel: -
• Gain Bandwidth Product: -
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant, Contains lead / RoHS non-compliant

APPLICATIONS INFORMATION
BASIC CONNECTION
Figure 36 shows the basic connection circuit for the AD8223.
The +V
The supply can be either bipolar (V
supply (−V
be capacitively decoupled close to the power pins of the device.
For best results, use surface-mount 0.1 μF ceramic chip capacitors
and 10 μF electrolytic tantalum capacitors.
The input voltage, which can be either single-ended (tie either
−IN or +IN to ground) or differential, is amplified by the
programmed gain. The output signal appears as the voltage
difference between the output pin and the externally applied
voltage on the REF input.
DIFFERENTIAL OUTPUT
Figure 37 shows how to create a differential output in-amp. An
OP1177
amp drives the AD8223 reference pin, the AD8223 can still
ensure that the differential voltage is correct. Errors from the
op amp or mismatched resistors are common to both outputs
and are thus common mode. These common-mode errors
should be rejected by the next device in the signal chain.
S
op amp creates the inverted output. Because the op
and −V
+IN
–IN
S
= 0 V, +V
Figure 37. Differential Output Using Op Amp
S
AD8223
terminals are connected to the power supply.
REF
V
IN
S
= +3 V to +24 V). Power supplies should
R
20kΩ
20kΩ
G
A. DUAL SUPPLY
+
–
R
R
G
G
+V
–V
S
S
S
REF
OUTPUT
–
= ±2 V to ±12 V) or single
+2V TO +12V
–2V TO –12V
OP1177
0.1µF
0.1µF
V
REF
+
+
+
10µF
10µF
+OUT
–OUT
V
REF (INPUT)
OUT
Figure 36. Basic Connections
Rev. 0 | Page 17 of 20
V
OUTPUT BUFFERING
The AD8223 is designed to drive loads of 10 kΩ or greater. If
the load is less than this value, buffer the AD8223 output with a
precision single-supply op amp such as the OP113. This op amp
can swing from 0 V to 4 V on its output while driving a load as
small as 600 Ω.
CABLES
Receiving from a Cable
In many applications, shielded cables are used to minimize
noise; for best CMR over frequency, the shield should be
properly driven. Figure 39 shows an active guard drive that
is configured to improve ac common-mode rejection by
bootstrapping the capacitances of input cable shields, thus
minimizing the capacitance mismatch between the inputs.
IN
R
G
V
100Ω
IN
B. SINGLE SUPPLY
+
R
R
–
+V
G
G
R
G
S
REF
OUTPUT
+INPUT
–INPUT
Figure 39. Common-Mode Shield Driver
+3V TO +24V
AD8031
0.1µF
+
–
AD8223
5V
Figure 38. Output Buffering
0.1µF
+
10µF
REF
R
R
2
2
G
G
V
REF (INPUT)
OUT
2
1
8
3
AD8223
+
–
OP113
–V
5V
4
+V
S
7
0.1µF
S
5
6
V
V
REFERENCE
AD8223
OUT
OUT