FEATURES

APPLICATIONS

1M

Ω

R

F

100k

Ω

+5V

7

2

3

4

6

OPA380

67pF

75pF

−5V

R

P

(Optional

Pulldown

Resistor)

V

OUT

(0V to 4.4V)

Photodiode

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 25

µV, 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 trans-

impedance 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 100

µA 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.

OPA380 RELATED DEVICES

PRODUCT

FEATURES

OPA300

150MHz CMOS, 2.7V to 5.5V Supply

OPA350

500

OPA335

10

OPA132

16MHz GBW, Precision FET Op Amp,

±15V

OPA656/7

230MHz, Precision FET,

±5V

LOG112

LOG amp, 7.5 decades,

±4.5V to ±18V Supply

LOG114

LOG amp, 7.5 decades,

±2.25V to ±5.5V Supply

IVC102

Precision Switched Integrator

DDC112

Dual Current Input, 20-Bit ADC

OPA380

OPA2380

SBOS291G − NOVEMBER 2003 − REVISED SEPTEMBER 2007

Precision, High-Speed

Transimpedance Amplifier

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.

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 2003-2007, Texas Instruments Incorporated

All trademarks are the property of their respective owners.

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.