OPA657

SBOS197B – DECEMBER 2001 – REVISED MAY 2004

www.ti.com

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 © 2001-2004, Texas Instruments Incorporated

1.6GHz, Low-Noise, FET-Input

OPERATIONAL AMPLIFIER

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.

FEATURES

q HIGH GAIN BANDWIDTH PRODUCT: 1.6GHz

q HIGH BANDWIDTH 275MHz (G = +10)

q LOW INPUT OFFSET VOLTAGE:

q LOW INPUT BIAS CURRENT: 2pA

q HIGH OUTPUT CURRENT: 70mA

q FAST OVERDRIVE RECOVERY

APPLICATIONS

q WIDEBAND PHOTODIODE AMPLIFIER

q WAFER SCANNING EQUIPMENT

q ADC INPUT AMPLIFIER

q TEST AND MEASUREMENT FRONT END

q HIGH GAIN PRECISION AMPLIFIER

SLEW VOLTAGE

BW

RATE

NOISE

DEVICE

(V) (MHz) (V/

OPA355

+5

200

300

5.80

Unity-Gain Stable CMOS

OPA655

±5

400

290

6

Unity-Gain Stable FET-Input

OPA656

±5

500

170

7

Unity-Gain Stable FET-Input

OPA627

±15

16

55

4.5

Unity-Gain Stable FET-Input

THS4601

±15 180

100

5.4

Unity-Gain Stable FET-Input

RELATED OPERATIONAL AMPLIFIER PRODUCTS

DESCRIPTION

The OPA657 combines a high gain bandwidth, low distor-tion,

voltage-feedback op amp with a low voltage noise JFET-input

stage to offer a very high dynamic range amplifier for high

precision ADC (Analog-to-Digital Converter) driving or wideband

transimpedance applications. Photodiode applications will see

improved noise and bandwidth using this decompensated,

high gain bandwidth amplifier.

Very low level signals can be significantly amplified in a single

OPA657 gain stage with exceptional bandwidth and accuracy.

Having a high 1.6GHz gain bandwidth product will give >

10MHz signal bandwidths up to gains of 160V/V (44dB). The

very low input bias current and capacitance will support this

performance even for relatively high source impedances.

Broadband photodetector applications will benefit from the low

voltage noise JFET inputs for the OPA657. The JFET input

contributes virtually no current noise while for broadband

applications, a low voltage noise is also required. The low

sensitivity for higher bandwidth applications. The example

shown below will give a total equivalent input noise current of

OPA657

OPA657

Wideband Photodiode Transimpedance Amplifier

(12pF)

λ

–V

b

200k

Ω

V

O

0.1pF

Frequency

200k

Ω TRANSIMPEDANCE BANDWIDTH

116

106

96

86

76

66

100kHz

1MHz

10MHz

50MHz

10MHz Bandwidth

All trademarks are the property of their respective owners.