Texas Instruments OPA340PA

Overview

OPA340PA from Texas Instruments is a single-supply, rail-to-rail input/output CMOS operational amplifier optimized for driving sampling A/D converters such as the ADS7816. It delivers 5.5 MHz gain-bandwidth, 6 V/µs slew rate, and output swing within 1 mV of rails under 100-kΩ load - enabling high-fidelity signal conditioning in 0–5 V data acquisition systems.

For engineers reviewing the OPA340PA datasheet, OPA340PA pinout, OPA340PA application, or OPA340PA equivalent, key selection criteria include rail-to-rail input range extending 500 mV beyond supply rails, low 750 µA quiescent current per channel, THD+N of 0.0007% at 1 kHz, and compatibility with micro-power 12-bit ADC interfaces requiring minimal charge injection buffering.

Technical Context

The OPA340PA uses a complementary N-channel/P-channel input stage to achieve rail-to-rail common-mode input range (–0.3 V to V_S + 0.3 V), with laser-trimmed offset matching to minimize transition-region degradation in PSRR and CMRR. Its class AB output stage drives 600-Ω loads while maintaining rail-to-rail swing.

It operates stably from 2.5 V to 5.5 V supply, with full specifications guaranteed from 2.7 V to 5 V and temperature range –40°C to 85°C. The device is unity-gain stable and supports capacitive loads up to 1000 pF in unity-gain configuration without external compensation.

Key Specifications

Pinout & Package

OPA340PA is supplied in an 8-pin PDIP (Plastic Dual In-line Package) with body size 9.81 mm × 6.35 mm. Pin functions are electrically identical to the SOIC variant but adapted for through-hole prototyping and legacy PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA340PA, the OPA340UA offers identical performance in a smaller, thermally superior SOIC package ideal for volume production, while the MCP6001T-I/OT trades bandwidth and distortion for lower cost and ultra-small SOT-23-5 footprint - making it suitable only for non-critical signal paths.

Availability

OPA340PA is available at Aetrix Electronics and suitable for data acquisition, process control, and audio signal conditioning requiring stable component supply across extended temperature ranges and long-lifecycle industrial programs.

Supply support for OPA340PA 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 company specializing in analog and embedded processing technologies, with leadership in precision amplifiers, data converters, and power management ICs.

The OPA340PA belongs to TI's MicroAmplifier™ series - designed specifically for low-voltage, single-supply systems demanding rail-to-rail performance, low power, and high AC fidelity in space-constrained applications.

FAQ

What is the maximum supply voltage rating for the OPA340PA?

The OPA340PA has an absolute maximum supply voltage of 5.5 V. Operation above this level risks permanent damage. Recommended operating range is 2.7 V to 5 V, though functional operation is supported from 2.5 V to 5.5 V. At 5.5 V, quiescent current remains within specification (≤950 µA), and output swing retains rail-to-rail capability under light loads. Always observe derating guidelines for reliability in high-temperature environments.

Does the OPA340PA support true rail-to-rail input with signals below ground?

Yes - the OPA340PA's input common-mode voltage range extends to –0.3 V (500 mV below ground when V– = 0 V), confirmed in the Electrical Characteristics table. This allows direct interfacing with bipolar sensor outputs or level-shifted signals without external biasing. However, input voltages exceeding the supply rails by more than 0.5 V require current limiting to ≤10 mA via series resistors to prevent ESD diode conduction and potential damage.

Can the OPA340PA drive a 1000-pF capacitive load in unity-gain configuration?

Yes - the OPA340PA is specified to drive up to 1000 pF in unity-gain configuration while maintaining stability, as documented in Section 7.3.4. This capability eliminates need for isolation resistors in many anti-aliasing filter designs. For loads >1000 pF or higher closed-loop gains, stability improves further; however, small-signal overshoot increases with capacitive loading, as shown in Figure 21 of the datasheet.

What is the typical THD+N performance of the OPA340PA at audio frequencies?

The OPA340PA achieves 0.0007% THD+N at 1 kHz with 3-V_PP output into 10-kΩ load (Section 6.7). This value holds across the 20 Hz–20 kHz audio band with minimal variation, supported by flat voltage noise density (25 nV/√Hz) and low harmonic generation. It meets Class A audio amplifier requirements for voice-band and consumer-grade line-level signal paths.

How does the OPA340PA handle input stage transitions between N- and P-channel pairs?

The OPA340PA uses laser trimming to minimize offset mismatch between its complementary N- and P-channel input stages, ensuring smooth transition across the ~400-mV region near V_S – 1.3 V. While PSRR and CMRR degrade slightly within this zone, the effect is bounded and characterized - e.g., CMRR remains ≥70 dB across –0.3 V to 5.3 V at V_S = 5 V. Designers should avoid sustained operation in this region for highest-precision DC applications.