Texas Instruments OPA340UA/2K5

Overview

OPA340UA/2K5 from Texas Instruments is a single-supply, rail-to-rail input/output CMOS operational amplifier optimized for driving sampling analog-to-digital converters (ADCs) 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 low-voltage (2.7–5.5 V) data acquisition systems.

For engineers reviewing the OPA340UA/2K5 datasheet, OPA340UA/2K5 pinout, OPA340UA/2K5 application, or OPA340UA/2K5 equivalent, key selection criteria include rail-to-rail input common-mode range extending 500 mV beyond supply rails, ultra-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 settling time and charge injection suppression.

Technical Context

The OPA340UA/2K5 uses a complementary N-channel/P-channel input stage to achieve rail-to-rail input operation, with a 400-mV transition region where both pairs are active - laser-trimmed to minimize offset mismatch and ensure smooth CMRR/PSRR behavior outside that zone. Its class AB output stage enables rail-to-rail output swing while maintaining >106 dB open-loop gain at 100-kΩ load.

Designed for unity-gain stability, it drives capacitive loads up to 1000 pF in buffer configuration and supports noninverting/inverting ADC driver topologies with RC filtering (e.g., 500 Ω + 3300 pF) to suppress high-frequency noise before the ADS7816 sampling input. Input bias current remains ≤10 pA across –40°C to 85°C.

Key Specifications

Pinout & Package

OPA340UA/2K5 is packaged in an 8-pin SOIC (D package), 4.90 mm × 3.91 mm body size, with exposed pad not present. Pin functions are electrically validated per TI SBOS073C Rev C.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA333AIDBVR and MCP6001T-E/OT, the OPA340UA/2K5 uniquely balances 5.5 MHz bandwidth, 6 V/µs slew rate, and 750 µA supply current - making it the optimal choice for 12-bit, 100-kSPS data acquisition where both speed and power efficiency are design constraints.

Availability

OPA340UA/2K5 is available at Aetrix Electronics and suitable for data acquisition, PCMCIA card design, and audio processing applications requiring stable component supply, consistent parametric performance, and long-term industrial temperature support (–40°C to 85°C).

Supply support for OPA340UA/2K5 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 OPA340 series belongs to TI's MicroAmplifier™ portfolio, designed specifically for single-supply, rail-to-rail signal conditioning in space- and power-constrained systems - including ADC drivers, portable instrumentation, and audio interfaces.

FAQ

What is the maximum supply voltage for OPA340UA/2K5?

The OPA340UA/2K5 supports an absolute maximum supply voltage of 5.5 V, with recommended operation from 2.7 V to 5.5 V. Operation at 5.5 V is permissible but requires verification of thermal dissipation in the 8-pin SOIC package, especially under heavy output loading. The device remains fully specified across this range, including rail-to-rail input/output behavior and 750 µA quiescent current.

Does OPA340UA/2K5 support true rail-to-rail input with signals below ground?

Yes - the OPA340UA/2K5 features a rail-to-rail input stage with a common-mode voltage range extending to –0.3 V (500 mV below ground at V– = 0 V). This allows direct connection of transducers with negative output excursions, such as thermocouples or AC-coupled sensors, without external level-shifting circuitry - confirmed in TI SBOS073C Section 6.7.

Can OPA340UA/2K5 drive the ADS7816 ADC directly?

Yes - the OPA340UA/2K5 is explicitly characterized in TI documentation (SBOS073C Figure 26) driving the ADS7816 in noninverting configuration. Its 6 V/µs slew rate and 1.6 µs 0.01% settling time meet the sampling aperture requirements of this 12-bit, 200-kSPS converter, and its rail-to-rail output ensures full 0–5 V input utilization.

What is the thermal resistance (RθJA) of the OPA340UA/2K5 SOIC package?

The OPA340UA/2K5 in 8-pin SOIC (D package) has a junction-to-ambient thermal resistance (RθJA) of 142°C/W, as specified in TI SBOS073C Table 6.4. This value assumes standard JEDEC 2-layer board conditions; actual thermal performance improves with PCB copper area and thermal vias beneath the package.

Is OPA340UA/2K5 unity-gain stable with capacitive loads?

Yes - the OPA340UA/2K5 is unity-gain stable and can drive up to 1000 pF of pure capacitive load without oscillation, as verified in TI SBOS073C Figure 21. For loads exceeding this, a 10–20 Ω series resistor at the output (Figure 25) restores phase margin while introducing negligible DC error (<0.2% with 10 kΩ load).