FEATURES

> 1MHz TRANSIMPEDANCE BANDWIDTH

EXCELLENT LONG-TERM VOS STABILITY

BIAS CURRENT: 50pA (max)

OFFSET VOLTAGE: 25μV (max)

DYNAMIC RANGE: 4 to 5 Decades

DRIFT: 0.1μV/°C (max)

GAIN BANDWIDTH: 90MHz

QUIESCENT CURRENT: 7.5mA

SUPPLY RANGE: 2.7V to 5.5V

SINGLE AND DUAL VERSIONS

MicroSize PACKAGE: MSOP-8

APPLICATIONS

PHOTODIODE MONITORING

PRECISION I/V CONVERSION

OPTICAL AMPLIFIERS

CAT-SCANNER FRONT-END

DESCRIPTION

The OPA380 family of transimpedance amplifiers provides

high-speed (90MHz Gain Bandwidth [GBW]) operation, with

extremely high precision, excellent long-term stability, and

very low 1/f noise. It is ideally suited for high-speed

photodiode applications. The OPA380 features an offset

voltage of 25μV, offset drift of 0.1μV/°C, and bias current of

50pA. The OPA380 far exceeds the offset, drift, and noise

performance that conventional JFET op amps provide.

The signal bandwidth of a transimpedance amplifier depends

largely on the GBW of the amplifier and the parasitic

capacitance of the photodiode, as well as the feedback

resistor. The 90MHz GBW of the OPA380 enables a transimpedance

bandwidth of > 1MHz in most configurations. The

OPA380 is ideally suited for fast control loops for power level

on an optical fiber.

As a result of the high precision and low-noise characteristics

of the OPA380, a dynamic range of 4 to 5 decades can be

achieved. For example, this capability allows the

measurement of signal currents on the order of 1nA, and up

to 100μA in a single I/V conversion stage. In contrast to

logarithmic amplifiers, the OPA380 provides very wide

bandwidth throughout the full dynamic range. By using an

external pull-down resistor to –5V, the output voltage range

can be extended to include 0V.

The OPA380 (single) is available in MSOP-8 and SO-8

packages. The OPA2380 (dual) is available in the

miniature MSOP-8 package. They are specified from

–40°C to +125°C.