AD8253ARMZ-RL Analog Devices Inc, AD8253ARMZ-RL Datasheet - Page 20

• Manufacturer Part Number: AD8253ARMZ-RL
• Description: IC,Instrumentation Amplifier,SINGLE,CMOS,TSSOP,10PIN,PLASTIC
• Manufacturer: Analog Devices Inc
• Series: iCMOS®r

Specifications of AD8253ARMZ-RL

• Amplifier Type: Instrumentation
• Number Of Circuits: 1
• Slew Rate: 20 V/µs
• -3db Bandwidth: 10MHz
• Current - Input Bias: 5nA
• Voltage - Input Offset: 150µV
• Current - Supply: 4.6mA
• Current - Output / Channel: 37mA
• Voltage - Supply, Single/dual (±): ±5 V ~ 15 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• Gain Bandwidth Product: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

AD8253
Values of R and C
Mismatch between the R × C
R × C
By using a value of C
C
improved.
DRIVING AN ANALOG-TO-DIGITAL CONVERTER
An instrumentation amplifier is often used in front of an analog-
to-digital converter to provide CMRR. Usually, instrumentation
amplifiers require a buffer to drive an ADC. However, the low
output noise, low distortion, and low settle time of the AD8253
make it an excellent ADC driver.
C
, the effect of the mismatch is reduced and performance is
C
at negative input degrades the CMRR of the AD8253.
R
R
C
should be chosen to minimize RFI.
C
C
C
D
C
D
C
Figure 58. RFI Suppression
that is 10 times larger than the value of
0.1µF
0.1µF
C
+IN
–IN
at the positive input and the
AD8253
+15V
–15V
REF
10µF
10µF
V
OUT
Rev. A | Page 20 of 24
In this example, a 1 nF capacitor and a 49.9 Ω resistor create an
antialiasing filter for the AD7612. The 1 nF capacitor also serves
to store and deliver necessary charge to the switched capacitor
input of the ADC. The 49.9 Ω series resistor reduces the burden
of the 1 nF load from the amplifier and isolates it from the kickback
current injected from the switched capacitor input of the AD7612.
Selecting too small a resistor improves the correlation between
the voltage at the output of the AD8253 and the voltage at the
input of the AD7612 but may destabilize the AD8253. A trade-
off must be made between selecting a resistor small enough to
maintain accuracy and large enough to maintain stability.
–IN
+IN
10μF
10μF
0.1µF
0.1µF
+15V
–15V
AD8253
DGND
WR
Figure 59. Driving an ADC
A1
A0
REF
DGND
49.9Ω
1nF
0.1μF
+12V
AD7612
+5V
ADR435
–12V
0.1μF