Texas Instruments OPA380AIDRG4

Overview

OPA380AIDRG4 from Texas Instruments is a precision transimpedance amplifier optimized for high-speed photodiode current-to-voltage conversion, featuring 90MHz gain bandwidth, 25µV max offset voltage, 0.1µV/°C max drift, 50pA max input bias current, and 1MHz transimpedance bandwidth in typical configurations. It operates from 2.7V to 5.5V and delivers 4–5 decades of dynamic range (1nA to 100µA) in single-stage I/V conversion for optical front-ends.

For engineers reviewing the OPA380AIDRG4 datasheet, OPA380AIDRG4 pinout, OPA380AIDRG4 application, or OPA380AIDRG4 equivalent, key selection considerations include transimpedance stability with photodiode capacitance, output swing extension to 0V using an external pulldown resistor, low 1/f noise performance, and guaranteed operation across –40°C to +125°C.

Technical Context

The OPA380AIDRG4 employs an auto-zero architecture combined with a continuous-time 90MHz signal-path amplifier, correcting offset every 100µs to achieve exceptional long-term VOS stability (≤1µV variation in 300-hour life test). Its internal topology eliminates phase inversion during input overvoltage and enables fast overload recovery (100ns from positive rail).

Designed specifically for inverting transimpedance configurations, it uses the noninverting input as a fixed bias node and supports optional negative-rail pull-down (e.g., –5V via 2kΩ resistor) to extend output swing to 0V while maintaining linearity and accuracy across temperature.

Key Specifications

Pinout & Package

OPA380AIDRG4 is housed in an MSOP-8 package (3.0mm × 3.0mm, 0.65mm pitch), thermally enhanced for high-precision analog operation in compact optical modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transimpedance amplifier applications.

Compared with OPA380AIDRG4, OPA300IDBVR trades offset precision and long-term stability for higher bandwidth, while OPA335AIDBVR sacrifices speed for ultra-low offset and zero-drift performance-neither offers the balanced combination of 90MHz GBW, 25µV VOS, and 1MHz transimpedance bandwidth that defines the OPA380AIDRG4's role in high-fidelity optical front-ends.

Availability

OPA380AIDRG4 is available at Aetrix Electronics and suitable for photodiode monitoring, CAT-scan front-end electronics, and precision optical amplifier design requiring stable component supply across automotive, medical, and industrial temperature ranges.

Supply support for OPA380AIDRG4 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog and embedded processing technologies, with deep expertise in precision op amps and signal-chain solutions.

The OPA380AIDRG4 belongs to TI's precision transimpedance amplifier product line, engineered specifically for high-speed, low-noise photodiode interfacing in medical imaging, analytical instrumentation, and fiber-optic communication systems.

FAQ

What is the maximum photodiode capacitance supported by OPA380AIDRG4 to maintain 1MHz transimpedance bandwidth?

The OPA380AIDRG4 achieves >1MHz transimpedance bandwidth with photodiode capacitances up to 100pF when using standard compensation techniques (e.g., CF = 0.5pF with RF = 10MΩ). As shown in Figure 7 of the SBOS291G datasheet, bandwidth degrades predictably with increasing CDIODE-e.g., 10pF yields ~10MHz, while 100pF sustains ~1MHz. Layout parasitics must remain below 0.2pF (CSTRAY) to meet specification.

Does OPA380AIDRG4 require external components to achieve 0V output swing?

Yes, OPA380AIDRG4 requires an external pulldown resistor (e.g., 2kΩ) connected between VOUT (Pin 3) and a negative supply (e.g., –5V) to extend output swing to 0V. Without this resistor, output swing is limited to ≥100mV above V– (ground). The datasheet confirms this in Figure 3 and Section "Achieving Output Swing to Ground", specifying guaranteed 0V operation with RP = 2kΩ to –5V across –40°C to +125°C.

How does the auto-zero architecture of OPA380AIDRG4 affect its noise performance at 10kHz?

At 10kHz, OPA380AIDRG4 exhibits 67nV/√Hz input voltage noise density-identical to conventional precision op amps-because its 10kHz auto-zero clock frequency is filtered internally, with residual energy appearing >20MHz. This preserves wideband SNR for optical signal chains while eliminating 1/f noise below 1kHz. Measured 0.1Hz–10Hz noise is only 3µVPP, confirming effective low-frequency noise suppression.

Can OPA380AIDRG4 operate with a 2.7V single supply while maintaining full specifications?

Yes, OPA380AIDRG4 is fully specified from 2.7V to 5.5V across –40°C to +125°C. All key parameters-including 25µV max VOS, 50pA max IB, 90MHz GBW, and 1MHz transimpedance bandwidth-are guaranteed at VS = 2.7V. Quiescent current remains 7.5mA (typ), and output swing retains ≥600mV from V+ and ≥100mV from V– with 2kΩ load, as verified in Electrical Characteristics Table 1.

What is the absolute maximum input voltage range for OPA380AIDRG4 when powered from +5V/0V supplies?

With +5V/0V supplies, OPA380AIDRG4 input terminals tolerate –0.5V to +5.5V (i.e., V– –0.5V to V+ +0.5V), per Absolute Maximum Ratings. Input current must be limited to ≤10mA if voltages exceed this range, as ESD clamps conduct beyond ±500mV of rails. Common-mode input range is 0V to +3.2V (V– to V+ –1.8V), so inputs must stay within this window for valid operation-exceeding it causes invalid output but no latch-up or inversion.