OP467_07 Datasheet, PDF (15/20 Pages) Analog Devices – Quad Precision, High Speed Operational Amplifier

0.01% 10V STEP
V_S = ±15V
NEG SLOPE
2.5mV
–2.5mV
Figure 45. Instrumentation Amplifier Settling Time to 0.01% for a
10 V Step Input (Negative Slope)
0.01% 10V STEP
V_S = ±15V
POS SLOPE
2.5mV
–2.5mV
Figure 46. Instrumentation Amplifier Settling Time to 0.01% for a
10 V Step Input (Positive Slope)
TO ^2kΩ
INPUT
TO 2kΩ
IN-AMP
OUTPUT
+V_S
+
+
AD9617
1kΩ
ERROR
TO SCOPE
61.9Ω
–V_S
549Ω
Figure 47. Settling Time Measurement Circuit
OP467
2 MHz BIQUAD BAND-PASS FILTER
The circuit in Figure 48 is commonly used in medical imaging
ultrasound receivers. The 30 MHz bandwidth is sufficient to
accurately produce the 2 MHz center frequency, as the measured
response shows in Figure 49. When the bandwidth of the op
amp is too close to the center frequency of the filter, the internal
phase shift of the amplifier causes excess phase shift at 2 MHz,
which alters the response of the filter. In fact, if the chosen op
amp has a bandwidth close to 2 MHz, the combined phase shift
of the three op amps causes the loop to oscillate.
Careful consideration must be given to the layout of this circuit
as with any other high speed circuit.
If the phase shift introduced by the layout is large enough, it can
alter the circuit performance, or worse, cause oscillation.
R6
1kΩ
C1
50pF
R1
3kΩ
2kΩ
1/4
OP467
V_IN
R2
2kΩ
1/4
OP467
R4
2kΩ
R3
2kΩ
1/4
OP467
V_OUT
C2
50pF
R5
2kΩ
1/4
OP467
Figure 48. 2 MHz Biquad Filter
0
–10
–20
–30
–40
10k
100k
1M
10M
FREQUENCY (Hz)
Figure 49. Biquad Filter Response
100M
Rev. F | Page 15 of 20