Datasheet

OPA692
14
SBOS236E
www.ti.com
exceeding 5MHz. The high slew rate, exceptional output
swing, and high linearity of the OPA692 make it an ideal
single-supply ADC driver. Figure 3 shows an example input
interface to a very high performance 10-bit, 60MSPS CMOS
converter.
The OPA692 in the circuit of Figure 3 provides 190MHz
bandwidth operating at a signal gain of +2 with a 2V
PP
output
swing. The noninverting input bias voltage is referenced to the
midpoint of the ADC signal range by dividing off the top and
bottom of the internal ADC reference ladder. With the gain
resistor (R
G
) AC-coupled, this bias voltage has a gain of +1 to
the output, centering the output voltage swing as well. Tested
performance at a 20MHz analog input frequency and a 60MSPS
clock rate on the converter gives > 58dBc SFDR.
WIDEBAND VIDEO MULTIPLEXING
One common application for video speed amplifiers that
include a disable pin is to wire multiple amplifier outputs
together, then select which one of several possible video
inputs to source onto a single line. This simple wired-OR
video multiplexer can be easily implemented using the
OPA692, as shown in Figure 4.
FIGURE 3. Wideband, AC-Coupled, Single-Supply ADC Driver.
FIGURE 4. 2-Channel Video Multiplexer.
OPA692
402Ω
+2.5V DC Bias
ADS826
10-Bit
60MSPS
50Ω
2Vp-p
DIS
22pF
Input
402Ω
REFB
REFT
CM
Input
0.1µF
0.1µF
1Vp-p
2kΩ
0.1µF
+3.5V
2kΩ
0.1µF
+1.5V
+5V
Clock
+5V
R
G
R
F
OPA692
2kΩ
V
OUT
75Ω Cable
RG-59
68.1Ω
68.1Ω
75Ω
402Ω402Ω
Video 1
+5V
+5V
|
V
OUT
| < 2.6V
–5V
OPA692
2kΩ
75Ω
402Ω402Ω
Video 2
–5V
+5V
V
DIS
DIS
DIS