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.

OPA6

98

Unity-Gain Stable, Wideband

Voltage Limiting Amplifier

FEATURES

q HIGH LINEARITY NEAR LIMITING

q FAST RECOVERY FROM OVERDRIVE: 1ns

q LIMITING VOLTAGE ACCURACY:

q –3dB BANDWIDTH (G = +1): 450MHz

q GAIN BANDWIDTH PRODUCT: 250MHz

q SLEW RATE: 1100V/

q

q HIGH-GAIN VERSION AVAILABLE: OPA699

APPLICATIONS

q FAST LIMITING ANALOG-TO-DIGITAL

CONVERTER (ADC) INPUT BUFFERS

q CCD PIXEL CLOCK STRIPPING

q VIDEO SYNC STRIPPING

q HF MIXERS

q IF LIMITING AMPLIFIERS

q AM SIGNAL GENERATION

q NONLINEAR ANALOG SIGNAL PROCESSING

q OPA688 UPGRADE

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

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.

OPA698

SBOS258B – NOVEMBER 2002 – REVISED SEPTEMBER 2003

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Copyright © 2002-2003, Texas Instruments Incorporated

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.

OPA698

V

4

2

3

7

5

8

6

V

+3.5V

+1.5V

V

IN

REFB

REFT

IN

0.1

µF

100pF

V

V

0.1

µF

0.1

µF

0.1

µF

402

Ω

24.9

Ω

562

Ω

102

Ω

402

Ω

715

Ω

715

Ω

102

Ω

562

Ω

ADS822

10-Bit

40MSPS

10-Bit

Data

V

INT/EXT

RSEL

+V

S

GND

Single-Supply Limiting ADC Input Driver