®

OPA643

1

Wideband Low Distortion, High Gain

OPERATIONAL AMPLIFIER

®

OPA643

APPLICATIONS

q BASE STATION ADC PREAMP

q ADC/DAC BUFFER AMPLIFIER

q LOW DISTORTION IF AMPLIFIER

q LOW NOISE, BROADBAND,

TRANSIMPEDANCE AMPLIFIER

q LOW NOISE PREAMPLIFIER

q VIDEO AMPLIFICATION

q TEST INSTRUMENTATION

OPA643

OPA658

OPA643

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111 • Twx: 910-952-1111

Internet: http://www.burr-brown.com/ • FAXLine: (800) 548-6133 (US/Canada Only) • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

FEATURES

q LOW DISTORTION: –90dBc at 5MHz

q LOW NOISE: 2.3nV/

√Hz

q GAIN-BANDWIDTH PRODUCT: 800MHz

q AVAILABLE IN SOT23-5 PACKAGE

q STABLE IN GAINS

q HIGH SLEW RATE: 1000V/

q HIGH OPEN-LOOP GAIN: 95dB

q HIGH OUTPUT CURRENT:

DESCRIPTION

The OPA643 provides a level of speed and dynamic

range previously unattainable in a monolithic op amp.

Using a de-compensated voltage feedback architec-

ture with two internal gain stages, the OPA643 achieves

exceptionally low harmonic distortion over a wide

frequency range. The "classic" differential input pro-

vides all the familiar benefits of precision op amps,

such as bias current cancellation and very low invert-

ing current noise compared with wideband current

feedback op amps. High slew rate and open-loop gain,

along with low input noise and high output current

drive make the OPA643 ideal for very high dynamic

range requirements.

The high gain bandwidth product for the gain

≥ 3

stable OPA643 makes it particularly suitable for

wideband transimpedance amplifiers and moderate gain

IF amplifier applications. External compensation

techniques may be used to apply the OPA643 at low

gains giving exceptionally low distortion and frequency

response flatness. Where unity gain stability with

comparable distortion performance is required, consider

the OPA642.

806

Ω

50

Ω

1Vp-p

10MHz

OPA643

47pF

REFT

+5V

REFB

ADS805

12-Bit

20MSPS

Measured

80dB SFDR

Analog

Input

56.9

Ω

0.1µF

0.1µF

402

Ω

5k

Ω

High Dynamic Range 20MSPS Digitizer

5k

Ω

0.1µF

2Vp-p

+5V

–5V

14pF

280

Ω

0.1µF

Low Gain

Compensation

50

Ω

Source

2.7pF

PDS-1191D

Printed in U.S.A. March, 1998

SBOS025