AD8031AR-REEL Analog Devices Inc, AD8031AR-REEL Datasheet - Page 15

• Manufacturer Part Number: AD8031AR-REEL
• Description: IC OPAMP VF R-R LP LDIST 8SOIC
• Manufacturer: Analog Devices Inc

Specifications of AD8031AR-REEL

• Rohs Status: RoHS non-compliant
• Design Resources: High Speed, Precision, Differential AC-Coupled Drive Circuit for AD7625 (CN0080) Single-Ended-to-Differential High Speed Drive Circuit for 16-Bit, 10 MSPS AD7626 ADC (CN0105)
• Amplifier Type: Voltage Feedback
• Number Of Circuits: 1
• Output Type: Rail-to-Rail
• Slew Rate: 35 V/µs
• -3db Bandwidth: 80MHz
• Current - Input Bias: 450nA
• Voltage - Input Offset: 1000µV
• Current - Supply: 900µA
• Current - Output / Channel: 15mA
• Voltage - Supply, Single/dual (±): 2.7 V ~ 12 V, ±1.35 V ~ 6 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Gain Bandwidth Product: -

DRIVING CAPACITIVE LOADS
Capacitive loads interact with an op amp’s output impedance to
create an extra delay in the feedback path. This reduces circuit
stability and can cause unwanted ringing and oscillation. A
given value of capacitance causes much less ringing when the
amplifier is used with a higher noise gain.
The capacitive load drive of the AD8031/AD8032 can be
increased by adding a low valued resistor in series with the
capacitive load. Introducing a series resistor tends to isolate the
capacitive load from the feedback loop, thereby diminishing its
influence. Figure 46 shows the effects of a series resistor on the
capacitive drive for varying voltage gains. As the closed-loop
gain is increased, the larger phase margin allows for larger
capacitive loads with less overshoot. Adding a series resistor at
lower closed-loop gains accomplishes the same effect. For large
capacitive loads, the frequency response of the amplifier is
dominated by the roll-off of the series resistor and capacitive load.
Rev. D | Page 15 of 20
1000
100
10
1
Figure 46. Capacitive Load Drive vs. Closed-Loop Gain
0
V
200mV STEP
WITH 30% OVERSHOOT
R
S
S
= 5V
= 0Ω, 5Ω
R
1
S
= 20Ω
CLOSED-LOOP GAIN (V/V)
2
R
G
R
3
AD8031/AD8032
S
R
= 20Ω
F
R
R
S
4
S
= 5Ω
R
S
V
C
= 0Ω
OUT
L
5