AD8202 Analog Devices, AD8202 Datasheet - Page 13

• Manufacturer Part Number: AD8202
• Description: High Common-Mode Voltage, Single-Supply Difference Amplifier
• Manufacturer: Analog Devices

Specifications of AD8202

• Filter Option: Yes
• Common Mode Input (v)min: --8V
• Common Mode Input (v)max: +28V
• Bandwidth G=10 (khz Typ): 50kHz
• Cmrr (db): 82dB
• Vcc-vee: 3.5V to 12V

Data Sheet
An increase in the A2 bias current, in addition to the output
saturation voltage of A1, directly affects the output voltage of
the
how to calculate the correct output voltage swing of the
AD8202, by taking all variables into account, follows:
•
•
•
Figure 41. A2 Input Bias Current vs. Input Voltage and Temperature. The
AD8202
Amplifier A1 output saturation potential can drop as low
as 20 mV at its output.
A2 typical input bias current of 40 nA multiplied by the
100 kΩ preamplifier output resistor produces
Total voltage at the A2 input equals the output saturation
voltage of A1 combined with the voltage error generated
by the input bias current
–140
–120
–100
–80
–60
–40
–20
20 mV + 4 mV = 24 mV
0
Shaded Area is the Bias Current from +125°C to −40°C.
40 nA × 100 kΩ = 4 mV at the A2 input
0
V
TEMPERATURE RANGE =
system (Pin 3 and Pin 4 shorted). An example of
+125°C TO –40°C
SUPPLY
= 5V
0.5
DIFFERENTIAL-MODE VOLTAGE (V)
1.0
1.5
2.0
2.5
Rev. E | Page 13 of 20
•
•
For an example of the effect of changes in A2 input bias current
vs. applied input potentials, see Figure 41. The change in bias
current causes a change in error voltage at the input of the
buffer amplifier. This results in a change in overall error
potential at the output of the buffer amplifier.
The total error at the input of A2, 24 mV, multiplied by the
buffer gain generates a resulting error of 48 mV at the
output of the buffer. This is
saturation potential.
The high output voltage range of the
as 4.8 V. Therefore, assuming a typical A2 input bias
current, the output voltage range for the
to 4.8 V.
AD8202
system output low
AD8202
AD8202
is specified
AD8202
is 48 mV