OPA2652 Datasheet, PDF (10/15 Pages) Burr-Brown (TI) – Dual, 700MHz, Voltage-Feedback OPERATIONAL AMPLIFIER

BANDPASS FILTER
Figure 3 shows a single OPA2652 implementing a sixth-
order bandpass filter. This filter cascades two second-order
Sallen-Key sections with transmission zeros, and a double
real pole section. It has 0.3dB of ripple, –3dB frequencies of
450kHz and 11MHz, and –23dB frequencies of 315kHz and
16MHz. The 20.0Ω resistor isolates the first OPA2652 out-
put from capacitive loading. This improves stability with
minimal impact on the filter response. Figure 4 shows the
nominal response simulated by SPICE.
0
–5
–10
–15
–20
–25
–30
–35
–40
10k
100k
1M
10M
Frequency (Hz)
100M
FIGURE 4. Nominal Filter Response.
VIDEO LINE DRIVER
Figure 5 shows the OPA2652 used as a video line driver. Its
outstanding differential gain and phase allow it to be used in
studio equipment, while its low cost and SOT23-8 package
option will support consumer applications.
Video
Input
75.0Ω
+5V
1/2
OPA2652
402Ω
–5V
402Ω
75.0Ω
Video
Output
FIGURE 5. Video Line Driver.
PULSE DELAY CIRCUIT
Figure 6 shows the OPA2652 used in a pulse delay circuit.
This circuit cascades the two op amps in the OPA2652, each
forming a single pole, active allpass filter. The overall gain
is +1, and the overall delay through the filter is:
t_GD = n(2RC), overall group delay
n= 2, the number of cascaded stages
2.2nF
140Ω
2.10kΩ
V_IN
1.30kΩ
1.0nF
1.0nF
143Ω
V_OUT
200Ω
100pF
2.7nF
100Ω
+5V
1/2
OPA2652
–5V
24.9Ω
FIGURE 3. Bandpass Filter.
®
OPA2652
10
+5V
1/2
OPA2652
1% Resistors
5% Capacitors
–5V _24.9Ω
180pF
225Ω
158Ω
18pF
20.0Ω ^12pF
150pF
107Ω