FEATURES
REDUCED BANDWIDTH CHANGE VERSUS GAIN
150MHz BANDWIDTH G = +2
> 90MHz BANDWIDTH TO GAIN > +10
LOW DISTORTION: < –69dBc at 5MHz
HIGH OUTPUT CURRENT: 110mA
SINGLE +5V TO +12V SUPPLY OPERATION
DUAL ±2.5V TO ±6V SUPPLY OPERATION
LOW SUPPLY CURRENT: 0.94mA
LOW SHUTDOWN CURRENT: 100μA

APPLICATIONS
LOW POWER BROADCAST VIDEO DRIVERS
EQUALIZING FILTERS
SAW FILTER HIGH GAIN POST AMPLIFIERS
SHORT LOOP ADSL CO DRIVERS
MULTICHANNEL SUMMING AMPLIFIERS
PROFESSIONAL CAMERAS
ADC INPUT DRIVERS

DESCRIPTION
The OPA683 provides a new level of performance in very lowpower,
wideband, current feedback amplifiers. This CFBplus amplifier
is among the first to use an internally closed-loop input buffer
stage that enhances performance significantly over earlier lowpower
CFB amplifiers. While retaining the benefits of very low
power operation, this new architecture provides many of the
advantages of a more ideal CFB amplifier. The closed-loop input
stage buffer gives a very low and linearized impedance path at the
inverting input to sense the feedback error current. This improved
inverting input impedance gives exceptional bandwidth retention to
much higher gains and improved harmonic distortion over earlier
solutions limited by inverting input linearity. Beyond simple high
gain applications, the OPA683 CFBplus amplifier can allow the gain
setting element to be set with considerable freedom from amplifier
bandwidth interaction. This allows frequency response peaking
elements to be added, multiple input inverting summing circuits to
have greater bandwidth, and low-power line drivers to meet the
demanding requirements of studio cameras and broadcast video.
The output capability for the OPA683 also sets a new mark in
performance for very low-power current feedback amplifiers. Delivering
a full ±4VPP swing on ±5V supplies, the OPA683 also has
the output current to support this swing into a 100Ω load. This
minimal output headroom requirement is complemented by a
similar 1.2V input stage headroom giving exceptional capability for
single +5V operation.
The OPA683’s low 0.94mA supply current is precisely trimmed at
25°C. This trim, along with low shift over temperature and supply
voltage, gives a very robust design over a wide range of operating
conditions. System power may be further reduced by using the
optional disable control pin. Leaving this disable pin open, or holding
it HIGH, gives normal operation. If pulled LOW, the OPA683 supply
current drops to less than 100μA while the I/O pins go to a high
impedance state.