0

−10

−20

−30

−40

−50

−60

−70

−80

Frequency (Hz)

1k

10k

100k

1M

10M

100M

1G

C

1

C

2

V

IN

R

R

V

OUT

Low−Pass Negative Impedance Converter (NIC) Filter

Frequency Response of 20kHz and 10MHz

Low−Pass NIC Filters

20kHz

Low−Pass Filter

10MHz

Low−Pass Filter

OPA861

www.ti.com

SBOS338G – AUGUST 2005 – REVISED MAY 2013

Wide Bandwidth

Operational Transconductance

Amplifier (OTA)

Check for Samples: OPA861

The OTA or voltage-controlled current source can be

1

FEATURES

viewed as an ideal transistor. Like a transistor, it has

•

Wide Bandwidth (80MHz, Open-Loop, G = +5)

three terminals—a high impedance input (base), a

•

High Slew Rate (900V/µs)

low-impedance input/output (emitter), and the current

output (collector). The OPA861, however, is self-

•

High Transconductance (95mA/V)

biased and bipolar. The output collector current is

•

zero for a zero base-emitter voltage. AC inputs

•

Low Quiescent Current (5.4mA)

centered about zero produce an output current, which

is

bipolar

and

centered

about

zero.

The

APPLICATIONS

transconductance of the OPA861 can be adjusted

with

an

external

resistor,

allowing

bandwidth,

•

Video/Broadcast Equipment

quiescent

current,

and

gain

trade-offs

to

be

•

Communications Equipment

optimized.

•

High-Speed Data Acquisition

Used as a basic building block, the OPA861

•

Wideband LED Drivers

simplifies the design of AGC amplifiers, LED driver

circuits for fiber optic transmission, integrators for fast

•

Control Loop Amplifiers

pulses, fast control loop amplifiers and control

•

Wideband Active Filters

amplifiers for capacitive sensors, and active filters.

•

Line Drivers

The OPA861 is available in SO-8 and SOT23-6

surface-mount packages.

DESCRIPTION

The OPA861 is a versatile monolithic component

designed for wide-bandwidth systems, including high

performance video, RF and IF circuitry. The OPA861

is a wideband, bipolar operational transconductance

amplifier (OTA).

1

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.

PRODUCTION DATA information is current as of publication date.

Copyright © 2005–2013, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.