1FEATURES

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

• High Slew Rate (900V/μs)

• High Transconductance (95mA/V) self•

External I Q-Control

• Low Quiescent Current (5.4mA)

APPLICATIONS

• Video/Broadcast Equipment

• Communications Equipment

• High-Speed Data Acquisition

• Wideband LED Drivers

• Control Loop Amplifiers

• Wideband Active Filters

• Line Drivers

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).

The OTA or voltage-controlled current source can be

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

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

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

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

biased and bipolar. The output collector current is

zero for a zero base-emitter voltage. AC inputs

centered about zero produce an output current, which

is bipolar and centered about zero. The

transconductance of the OPA861 can be adjusted

with an external resistor, allowing bandwidth,

quiescent current, and gain trade-offs to be

optimized.

Used as a basic building block, the OPA861

simplifies the design of AGC amplifiers, LED driver

circuits for fiber optic transmission, integrators for fast

pulses, fast control loop amplifiers and control

amplifiers for capacitive sensors, and active filters.

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

surface-mount packages.