AD8278BRZ-RL Analog Devices Inc, AD8278BRZ-RL Datasheet - Page 17

• Manufacturer Part Number: AD8278BRZ-RL
• Description: SingleG=0/5.2 LowPowerWideInputRange
• Manufacturer: Analog Devices Inc

Specifications of AD8278BRZ-RL

• Amplifier Type: Differential
• Number Of Circuits: 1
• Output Type: Rail-to-Rail
• Slew Rate: 1.4 V/µs
• Gain Bandwidth Product: 1MHz
• Voltage - Input Offset: 50µV
• Current - Supply: 200µA
• Current - Output / Channel: 15mA
• Voltage - Supply, Single/dual (±): 2 V ~ 36 V, ±2 V ~ 18 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• -3db Bandwidth: -
• Current - Input Bias: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

POWER SUPPLIES
The AD8278 operates extremely well over a very wide range of
supply voltages. It can operate on a single supply as low as 2 V
and as high as 36 V, under appropriate setup conditions.
For best performance, the user must exercise care that the setup
conditions ensure that the internal op amp is biased correctly.
The internal input terminals of the op amp must have sufficient
voltage headroom to operate properly. Proper operation of the
part requires at least 1.5 V between the positive supply rail and
the op amp input terminals. This relationship is expressed in
the following equation:
For example, when operating on a +V
V
terminals are biased at 0 V, allowing more than the required 1.5 V
headroom. However, if V
input terminals of the op amp are biased at 0.66 V (G = ½). Now
the op amp does not have the required 1.5 V headroom and can
not function. Therefore, the user needs to increase the supply
voltage or decrease V
REF
= 0 V, it can be seen from Figure 47 that the op amps input
R1
R1
+
R2
V
REF
<
REF
+
V
to restore proper operation.
REF
S
−
= 1 V under the same conditions, the
1
5 .
V
S
= 2 V single supply and
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The AD8278 is typically specified at single- and dual-supplies,
but it can be used with unbalanced supplies as well; for example,
−V
must be kept below 36 V. The positive supply rail must be at
least 2 V above the negative supply and reference voltage.
Use a stable dc voltage to power the AD8278. Noise on the
supply pins can adversely affect performance. Place a bypass
capacitor of 0.1 μF between each supply pin and ground, as
close as possible to each supply pin. Use a tantalum capacitor
of 10 μF between each supply and ground. It can be farther
away from the supply pins and, typically, it can be shared by
other precision integrated circuits.
Figure 47. Ensure Sufficient Voltage Headroom on the Internal Op Amp
S
= −5 V, +V
S
= 20 V. The difference between the two supplies
R1 + R2
R1
R3
R1
(V
REF
R2
V
REF
Inputs
)
R1 + R2
R1
(V
R4
REF
)
AD8278