AD8251ARMZ-RL Analog Devices Inc, AD8251ARMZ-RL Datasheet - Page 18

• 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

AD8251
POWER SUPPLY REGULATION AND BYPASSING
The AD8251 has high PSRR. However, for optimal performance,
a stable dc voltage should be used to power the instrumentation
amplifier. Noise on the supply pins can adversely affect per-
formance. As in all linear circuits, bypass capacitors must be
used to decouple the amplifier.
Place a 0.1 μF capacitor close to each supply pin. A 10 μF tantalum
capacitor can be used farther away from the part (see Figure 55)
and, in most cases, it can be shared by other precision integrated
circuits.
INPUT BIAS CURRENT RETURN PATH
The AD8251 input bias current must have a return path to its
local analog ground. When the source, such as a thermocouple,
cannot provide a return current path, one should be created
(see Figure 56).
Figure 55. Supply Decoupling, REF, and Output Referred to Ground
DGND
+IN
–IN
AD8251
+V
–V
S
WR
S
DGND
A1
0.1µF
0.1µF
A0
REF
10µF
10µF
LOAD
OUT
Rev. B | Page 18 of 24
INPUT PROTECTION
All terminals of the AD8251 are protected against ESD. Note
that 2.2 kΩ series resistors precede the ESD diodes as shown in
Figure 51. The resistors limit current into the diodes and allow
for dc overload conditions 13 V above the positive supply and
13 V below the negative supply. An external resistor should be
used in series with each input to limit current for voltages
greater than 13 V beyond either supply rail. In either scenario,
the AD8251 safely handles a continuous 6 mA current at room
temperature. For applications where the AD8251 encounters
extreme overload voltages, external series resistors and low
leakage diode clamps, such as BAV199Ls, FJH1100s, or SP720s,
should be used.
CAPACITIVELY COUPLED
C
C
THERMOCOUPLE
TRANSFORMER
INCORRECT
AD8251
+V
–V
AD8251
AD8251
+V
–V
+V
–V
S
S
S
S
S
S
Figure 56. Creating an I
REF
REF
REF
f
HIGH-PASS
CAPACITIVELY COUPLED
=
BIAS
2πRC
10MΩ
1
Return Path
C
C
THERMOCOUPLE
TRANSFORMER
R
R
CORRECT
AD8251
AD8251
AD8251
+V
–V
+V
–V
+V
–V
S
S
S
S
S
S
REF
REF
REF