ad5539jq Analog Devices, Inc., ad5539jq Datasheet - Page 11

• Manufacturer Part Number: ad5539jq
• Description: Ultrahigh Frequency Operational Amplifier
• Manufacturer: Analog Devices, Inc.

REV. B
value of R
220
12.8, because the source resistance affects the noise gain.
Figures 31 and 32 show the small and large signal responses of
the circuit of Figure 29.
Figure 31. The Small-Signal Pulse Response of the Gain
of 3 Follower Circuit with R
Pin 12; Vertical Scale: 50 mV/div; Horizontal Scale:
5 ns/div
Figure 32. The Large-Signal Pulse Response of the Gain
of 3 Follower Circuit with R
Pin 12; Vertical Scale: 200 mV/div; Horizontal Scale:
5 ns/div
A Video Amplifier Circuit with 20 dB Gain (Terminated)
High gain applications (14 dB and up) require only a small lead
capacitance to obtain flat response. The 26 dB (20 dB termi-
nated) video amplifier circuit of Figure 33 has the response
shown in Figure 34 using only approximately 0.5-1 pF lead ca-
pacitance. Again, a small C
output or to Pin 12 with very little difference in response.
R
LAG
LAG
and a 50
, the higher the noise gain). For example, with a
source resistance, the noise gain will be
LEAD
LAG
LAG
can be connected, either to the
and C
and C
LEAD
LEAD
Compensation to
Compensation to
–11–
In color video applications, the quality of differential gain and
differential phase response is very important. Figures 35 and 36
show a circuit and test setup to measure the AD5539’s response
to a modulated ramp signal (0-90 IRE p-p ramp, 40 IRE p-p
modulation, 4.4 MHz).
Figures 37 and 38 show the differential gain and phase response.
Figure 33. A 20 dB Gain Video Amplifier for 75
Figure 34. Response of the 20 dB Video Amplifier
AD5539
Systems