Texas Instruments OPA344UA

Overview

OPA344UA from Texas Instruments is a single, rail-to-rail input/output CMOS operational amplifier optimized for unity-gain stability, low-power (150 µA typ), and precision operation from 2.7 V to 5.5 V supply. It delivers 1 MHz gain-bandwidth, 0.8 V/µs slew rate, and 0.006% THD+N at 1 kHz - enabling high-fidelity signal conditioning in space-constrained, battery-powered data acquisition and audio systems.

For engineers reviewing the OPA344UA datasheet, OPA344UA pinout, OPA344UA application, or OPA344UA equivalent, key selection considerations include its rail-to-rail input common-mode range extending 300 mV beyond supplies, output swing within 1 mV of rails (at light loads), ±0.2 mV max input offset voltage, and SOIC-8 packaging qualified for –40°C to +85°C industrial operation.

Technical Context

The OPA344UA employs a complementary differential input stage (N-channel + P-channel pairs) to achieve rail-to-rail input operation, with a 400 mV transition region where both stages are active - requiring careful biasing to avoid discontinuities in PSRR, CMRR, and THD. Its class AB output stage enables true rail-to-rail output swing into loads ≥ 50 kΩ while maintaining >104 dB open-loop gain.

This device is unity-gain stable and specified for single-supply operation only; it is not optimized for gains ≥ 5 (that role belongs to the OPA345 family). Its 1 MHz GBW and 0.8 V/µs slew rate support medium-speed sampling ADC driving (e.g., ADS7822) without external compensation.

Key Specifications

Pinout & Package

OPA344UA is housed in an 8-pin SOIC (SO-8) package (Package Drawing D), surface-mount compatible, with JEDEC-standard footprint and moisture sensitivity level (MSL) Level-2-260°C-1 year.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA344NA and OPA2344UA, the OPA344UA offers optimal balance of SOIC-8 manufacturability, thermal performance (θJA = 150°C/W), and single-amplifier simplicity for discrete signal path design - making it preferred for prototyping and mid-volume production where layout flexibility and test access matter.

Availability

OPA344UA is available at Aetrix Electronics and suitable for PCMCIA card design, portable data acquisition systems, and industrial process control modules requiring stable component supply, RoHS-compliant packaging, and guaranteed –40°C to +85°C operation.

Supply support for OPA344UA 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 delivering analog and embedded processing solutions, with over 50 years of innovation in precision op amps and signal chain ICs.

The OPA344UA belongs to TI's MicroAmplifier™ series - engineered specifically for low-power, rail-to-rail, single-supply operation in miniature, battery-powered instrumentation and portable electronics.

FAQ

What is the maximum supply voltage for the OPA344UA?

The OPA344UA has an absolute maximum supply voltage of 7.5 V (V+ to V–), but its specified operating range is 2.7 V to 5.5 V. Operation outside this range may cause parametric degradation or damage. For reliable long-term performance, maintain VS within 2.7–5.5 V - e.g., standard 3.3 V or 5 V rails. The OPA344UA is not rated for dual-supply ±5 V operation.

Is the OPA344UA unity-gain stable?

Yes, the OPA344UA is explicitly unity-gain stable per TI's SBOS107A datasheet. It requires no external compensation and maintains phase margin >45° at G = 1. This distinguishes it from the OPA345UA (optimized for G ≥ 5), making the OPA344UA ideal for voltage followers, active filters, and sensor buffers where gain = 1 is mandatory.

Can the OPA344UA drive capacitive loads?

The OPA344UA can directly drive up to 250 pF of pure capacitive load in unity-gain configuration while maintaining stability. For larger loads or mixed R+C loads, insert a 10–20 Ω series resistor between output and capacitance. This preserves DC accuracy (error <0.1% for RL > 10 kΩ) and suppresses ringing - critical when driving ADC input capacitors like those in the ADS7822.

What is the input common-mode voltage range of the OPA344UA?

The OPA344UA features a rail-to-rail input stage with a common-mode voltage range of –0.3 V to (V+) + 0.3 V. This allows inputs to extend 300 mV beyond both supply rails - essential for interfacing with sensors or DACs that swing near ground or V+. However, operation within the ~400 mV transition region near (V+) – 1.3 V may degrade PSRR and THD; biasing outside this zone is recommended for highest precision.

Does the OPA344UA have shutdown functionality?

No, the OPA344UA does not include an enable/shutdown pin or internal power-down mode. It operates continuously whenever powered within its 2.7–5.5 V supply range. For applications requiring low-quiescent-current sleep states, consider alternatives like the TLV246x or OPA365 families - but note these differ in GBW, noise, and rail-to-rail behavior. The OPA344UA's 150 µA IQ is already among the lowest for rail-to-rail CMOS op amps in its class.