OPA698
OPA
698
SBOS258B – NOVEMBER 2002 – REVISED SEPTEMBER 2003
Unity-Gain Stable, Wideband
Voltage Limiting Amplifier
FEATURES
q
q
q
q
q
q
q
q
HIGH LINEARITY NEAR LIMITING
FAST RECOVERY FROM OVERDRIVE: 1ns
LIMITING VOLTAGE ACCURACY:
±
10mV
–3dB BANDWIDTH (G = +1): 450MHz
GAIN BANDWIDTH PRODUCT: 250MHz
SLEW RATE: 1100V/
µ
s
±
5V AND +5V SUPPLY OPERATION
HIGH-GAIN VERSION AVAILABLE: OPA699
APPLICATIONS
q
FAST LIMITING ANALOG-TO-DIGITAL
CONVERTER (ADC) INPUT BUFFERS
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CCD PIXEL CLOCK STRIPPING
q
VIDEO SYNC STRIPPING
q
HF MIXERS
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IF LIMITING AMPLIFIERS
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AM SIGNAL GENERATION
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NONLINEAR ANALOG SIGNAL PROCESSING
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OPA688 UPGRADE
function at the output, as opposed to the input, gives the
specified limiting accuracy for any gain, and allows the
OPA698 to be used in all standard op amp applications.
Nonlinear analog signal processing will benefit from the
ability of the OPA698 to sharply transition from linear opera-
tion to output limiting. The quick recovery time supports
high-speed applications.
The OPA698 is available in an industry standard pinout SO-8
package. For higher gain, or transimpedance applications
requiring output limiting with fast recovery, consider the
OPA699.
V
S
= +5V
DESCRIPTION
The OPA698 is a wideband, unity-gain stable voltage-
feedback op amp that offers bipolar output voltage limiting.
Two buffered limiting voltages take control of the output
when it attempts to drive beyond these limits. This new
output limiting architecture holds the limiter offset error to
±10mV.
The op amp operates linearly to within 20mV of the
output limit voltages.
The combination of a narrow nonlinear range and the low
limiting offset allows the limiting voltages to be set within
100mV of the desired linear output range. A fast 1ns
recovery from limiting ensures that overdrive signals will be
transparent to the signal channel. Implementing the limiting
562Ω
V
H
= +3.6V
0.1µF
715Ω
0.1µF
V
IN
V
S
= +5V
3
7
8
OPA698
2
715Ω
4
REFB
402Ω
+1.5V
102Ω
402Ω
0.1µF
V
L
= +1.4V
0.1µF
562Ω
INT/EXT GND
5
6
24.9Ω
IN
100pF
ADS822
10-Bit
40MSPS
10-Bit
Data
V
S
= +5V
102Ω
+3.5V
REFT
RSEL
+V
S
Single-Supply Limiting ADC Input Driver
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 © 2002-2003, Texas Instruments Incorporated
www.ti.com
TI [ TEXAS INSTRUMENTS ]
