OPA
268
3
OPA2683
OPA
2683
www.ti.com
SBOS244H – MAY 2002 – REVISED JULY 2009
Very Low-Power, Dual, Current-Feedback
Operational Amplifier
FEATURES
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REDUCED BANDWIDTH CHANGE VERSUS GAIN
150MHz BANDWIDTH G = +2
> 80MHz BANDWIDTH TO GAIN > +10
LOW DISTORTION: < –65dBc at 5MHz
HIGH OUTPUT CURRENT: 110mA
SINGLE-SUPPLY OPERATION: +5V to +12V
DUAL-SUPPLY OPERATION:
±
2.5V to
±
6V
LOW SUPPLY CURRENT: 1.9mA Total
POWER SHUTDOWN VERSION: MSOP-10
APPLICATIONS
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LOW-POWER BROADCAST VIDEO DRIVERS
µ
POWER ACTIVE FILTERS
SHORT-LOOP ADSL CO DRIVERS
MULTICHANNEL SUMMING AMPLIFIERS
PROFESSIONAL CAMERAS
DIFFERENTIAL ADC INPUT DRIVERS
DESCRIPTION
The OPA2683 provides a new level of performance for dual, very
low-power, wideband, current-feedback amplifiers. This CFB
PLUS
amplifier is among the first to use an internally closed-loop input
buffer stage that significantly enhances performance over earlier
low-power, current-feedback (CFB) amplifiers. This new archi-
tecture provides many of the advantages of a more ideal CFB
amplifier while retaining the benefits of very low-power operation.
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 excep-
tional bandwidth retention to much higher gains and improved
harmonic distortion over earlier solutions limited by inverting input
linearity. Beyond simple high gain applications, the OPA2683
CFB
PLUS
amplifier can allow the gain setting element to be set with
considerable freedom from amplifier bandwidth interaction. This
flexibility allows frequency response peaking elements to be
added, multiple input inverting summing circuits to have greater
bandwidth, and low-power differential line drivers to meet the
demanding requirements of DSL.
The output capability for the OPA2683 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 OPA2683 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 OPA2683’s low 1.9mA total 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. Further system power reduction is possible using
the shutdown feature of the MSOP-10 package.
NONINVERTING SMALL-SIGNAL
FREQUENCY RESPONSE
6
3
G = 10 G = 1
G=2
V+
V
O
Normalized Gain (dB)
+
0
–3
–6
–9
–12
–15
R
F
= 953Ω
G = 50
G = 50
G = 10
V–
I
ERR
R
F
Z
(S)
I
ERR
R
G
G = 100
10
Frequency (Hz)
100
200
Low-Power
Amplifier
–18
1
U.S. Patent No. 6,724,260
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
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.
Copyright © 2002-2009, Texas Instruments Incorporated
www.ti.com
TI [ TEXAS INSTRUMENTS ]
