OPA683IDBVR Datasheet, PDF (1/31 Pages) Texas Instruments – Very Low-Power, Current Feedback RATIONAL AMPLIFIER With Disable

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OPA683
OPA683
OPA683
SBOS221E – NOVEMBER 2001 – REVISED JULY 2008
Very Low-Power, Current Feedback
OPERATIONAL AMPLIFIER With Disable
FEATURES
q REDUCED BANDWIDTH CHANGE VERSUS GAIN
q 150MHz BANDWIDTH G = +2
q > 90MHz BANDWIDTH TO GAIN > +10
q LOW DISTORTION: < –69dBc at 5MHz
q HIGH OUTPUT CURRENT: 110mA
q SINGLE +5V TO +12V SUPPLY OPERATION
q DUAL ±2.5V TO ±6V SUPPLY OPERATION
q LOW SUPPLY CURRENT: 0.94mA
q LOW SHUTDOWN CURRENT: 100µA
DESCRIPTION
The OPA683 provides a new level of performance in very low-
power, wideband, current feedback amplifiers. This CFB_plus ampli-
fier is among the first to use an internally closed-loop input buffer
stage that enhances performance significantly over earlier low-
power 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 CFB_plus 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
APPLICATIONS
q LOW POWER BROADCAST VIDEO DRIVERS
q EQUALIZING FILTERS
q SAW FILTER HIGH GAIN POST AMPLIFIERS
q SHORT LOOP ADSL CO DRIVERS
q MULTICHANNEL SUMMING AMPLIFIERS
q PROFESSIONAL CAMERAS
q ADC INPUT DRIVERS
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. De-
livering a full ±4V_PP 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.
V+
+
V_O
V–
I_ERR
Z_(S) I_ERR
R_F
R_G
Low-Power
Amplifier
U.S. Patent No. 6,724,260
OPA683 BANDWIDTH vs GAIN
9
6
G=2
G=5
3
0
–3
–6
–9
–12
–15
–18
–21 ^{RF = 1.2kΩ}
1
G = 10
G = 20
G = 50
G = 100
10
100 200
Frequency (MHz)
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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