AD8226BRZ-RL Analog Devices Inc, AD8226BRZ-RL Datasheet - Page 23

• Manufacturer Part Number: AD8226BRZ-RL
• Description: Precision InAmp
• Manufacturer: Analog Devices Inc

Specifications of AD8226BRZ-RL

• Amplifier Type: Instrumentation
• Number Of Circuits: 1
• Output Type: Rail-to-Rail
• Slew Rate: 0.6 V/µs
• -3db Bandwidth: 1.5MHz
• Current - Input Bias: 20nA
• Voltage - Input Offset: 100µV
• Current - Supply: 350µA
• Current - Output / Channel: 13mA
• Voltage - Supply, Single/dual (±): 2.2 V ~ 36 V, ±1.35 V ~ 18 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Gain Bandwidth Product: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIONS INFORMATION
DIFFERENTIAL DRIVE
Figure 64 shows how to configure the AD8226 for differ-
ential output.
The differential output is set by the following equation:
The common-mode output is set by the following equation:
The advantage of this circuit is that the dc differential accuracy
depends on the AD8226, not on the op amp or the resistors. In
addition, this circuit takes advantage of the precise control that the
AD8226 has of its output voltage relative to the reference voltage.
Although the dc performance and resistor matching of the op amp
affect the dc common-mode output accuracy, such errors are
likely to be rejected by the next device in the signal chain and
therefore typically have little effect on overall system accuracy.
V
V
DIFF_OUT
CM_OUT
+IN
–IN
RECOMMENDED OP AMPS: AD8515, AD8641, AD820.
RECOMMENDED R VALUES: 5kΩ to 20kΩ.
Figure 64. Differential Output Using an Op Amp
= (V
= V
AD8226
OUT+
OUT+
REF
− V
− V
OUT−
OUT−
R
R
)/2= V
= Gain × (V
BIAS
–
OP AMP
V
IN+
BIAS
+
− V
+OUT
–OUT
IN−
)
Rev. B | Page 23 of 28
Tips for Best Differential Output Performance
For best ac performance, an op amp with at least a 2 MHz gain
bandwidth and a 1 V/µs slew rate is recommended. Good choices
for op amps are the AD8641, AD8515, and AD820.
Keep trace lengths from the resistors to the inverting terminal
of the op amp as short as possible. Excessive capacitance at this
node can cause the circuit to be unstable. If capacitance cannot
be avoided, use lower value resistors.
For best linearity and ac performance, a minimum positive
supply voltage (+V
supply voltage required for optimum performance. In this mode,
V
at the input of the AD8226.
Table 9. Minimum Positive Supply Voltage
Temperature
Less than −10°C
−10°C to 25°C
More than 25°C
CM_MAX
indicates the maximum common-mode voltage expected
S
) is required. Table 9 shows the minimum
Equation
+V
+V
+V
S
S
S
> (V
> (V
> (V
CM_MAX
CM_MAX
CM_MAX
+ V
+ V
+ V
BIAS
BIAS
BIAS
)/2 + 1.4 V
)/2 + 1.25 V
)/2 + 1.1 V
AD8226