AD8251ARMZ-RL Analog Devices Inc, AD8251ARMZ-RL Datasheet - Page 21

• Manufacturer Part Number: AD8251ARMZ-RL
• Description: IC,Instrumentation Amplifier,SINGLE,TSSOP,10PIN,PLASTIC
• Manufacturer: Analog Devices Inc
• Series: iCMOS®r

Specifications of AD8251ARMZ-RL

• Amplifier Type: Instrumentation
• Number Of Circuits: 1
• Slew Rate: 30 V/µs
• -3db Bandwidth: 10MHz
• Current - Input Bias: 5nA
• Voltage - Input Offset: 70µV
• Current - Supply: 4.1mA
• Current - Output / Channel: 37mA
• Voltage - Supply, Single/dual (±): 10 V ~ 30 V, ±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

APPLICATIONS
DIFFERENTIAL OUTPUT
In certain applications, it is necessary to create a differential
signal. High resolution ADCs often require a differential input.
In other cases, transmission over a long distance can require
differential signals for better immunity to interference.
Figure 61 shows how to configure the AD8251 to output a
differential signal. An op amp, the AD817, is used in an
inverting topology to create a differential voltage. V
output midpoint according to the equation shown in the figure.
Errors from the op amp are common to both outputs and are
thus common mode. Likewise, errors from using mismatched
resistors cause a common-mode dc offset error. Such errors are
rejected in differential signal processing by differential input
ADCs or instrumentation amplifiers.
When using this circuit to drive a differential ADC, V
set using a resistor divider from the ADC reference to make the
output ratiometric with the ADC.
+5V
–5V
AMPLITUDE
V
IN
+12V
+IN
10μF
–12V
0.1μF
0.1μF
10μF
+
–
DGND
AD8251
+12V
–12V
Figure 61. Differential Output with Level Shift
G = 1
DGND
REF
WR
REF
sets the
A1
can be
A0
REF
4.99kΩ
4.99kΩ
Rev. B | Page 21 of 24
10pF
0.1µF
–12V
SETTING GAINS WITH A MICROCONTROLLER
–
V
V
OUT
AD817
OUT
B = –V
A = V
0.1µF
+
2
2
IN
IN
+12V
Figure 60. Programming Gain Using a Microcontroller
–IN
+IN
10μF
10μF
+ V
+ V
REF
REF
V
0V
AMPLITUDE
AMPLITUDE
REF
0.1µF
0.1µF
+2.5V
+2.5V
–2.5V
–2.5V
0V
0V
0V
+15V
–15V
+
–
AD8251
DGND
WR
A1
A0
REF
CONTROLLER
DGND
TIME
TIME
MICRO-
AD8251