Texas Instruments OPA342UAG4

Overview

OPA342UAG4 from Texas Instruments is a single, rail-to-rail input/output CMOS operational amplifier optimized for low-cost, low-power, miniature applications. It operates from 2.7V to 5.5V supply, delivers 1MHz bandwidth and 1V/µs slew rate, draws only 150µA typical quiescent current, and achieves output swing within 1mV of rails under light load - ideal for driving sampling ADCs in portable data acquisition systems.

For engineers reviewing the OPA342UAG4 datasheet, OPA342UAG4 pinout, OPA342UAG4 application, or OPA342UAG4 equivalent, key selection criteria include its rail-to-rail dynamic range at 2.7V operation, 0.006% THD+N at 1kHz, ±6mV max input offset voltage over temperature, and SOIC-8 package compatibility with space-constrained industrial and audio signal chains.

Technical Context

The OPA342UAG4 employs a complementary CMOS input stage enabling rail-to-rail common-mode input range extending 300mV beyond both supply rails, with a defined transition region near (V+) – 1.3V where PSRR and CMRR degrade. Its class AB output stage supports rail-to-rail output swing down to 1mV from rails with 100kΩ load while maintaining ≥104dB open-loop gain.

It is unity-gain stable and specified across –40°C to +85°C, with input bias current as low as ±0.2pA and input voltage noise density of 30nV/√Hz at 1kHz. The device drives up to 250pF capacitive loads in unity-gain configuration without external compensation.

Key Specifications

Pinout & Package

OPA342UAG4 is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package per JEDEC MS-012, with standard 1.27mm pitch and surface-mount footprint. Thermal resistance θ_JA is 150°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA333AIDBVR and MCP6001T-I/OT, the OPA342UAG4 uniquely balances 1MHz bandwidth, 1mV rail-to-rail output, 0.006% THD+N, and 150µA quiescent current in SOIC-8 - making it optimal for portable data acquisition and audio signal chains where speed, fidelity, and power coexist.

Availability

OPA342UAG4 is available at Aetrix Electronics and suitable for portable data acquisition, audio signal conditioning, process sensor interface, and consumer electronics analog front-end applications requiring stable component supply and RoHS-compliant packaging.

Supply support for OPA342UAG4 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 decades of expertise in precision op amps and signal chain solutions.

The OPA342UAG4 belongs to TI's MicroAmplifier™ series, designed specifically for low-power, miniature, rail-to-rail applications in portable instrumentation, audio, and industrial sensing - emphasizing ease of use, small size, and robust single-supply operation.

FAQ

What is the maximum capacitive load the OPA342UAG4 can drive in unity-gain configuration?

The OPA342UAG4 can directly drive up to 250pF of pure capacitive load in unity-gain configuration while maintaining stability. For larger loads, a 10Ω–20Ω series resistor between the output and capacitive load improves phase margin without degrading DC accuracy - a technique validated in TI's SBOS106A datasheet Figure 5. This capability makes OPA342UAG4 suitable for driving ADC input capacitance and long PCB traces in compact layouts.

Does the OPA342UAG4 support true rail-to-rail input when operating from a 2.7V supply?

Yes, the OPA342UAG4 supports rail-to-rail input with common-mode voltage range from –0.3V to (V+) + 0.3V - meaning it accepts inputs from –0.3V to +3.0V when VS = 2.7V. However, performance parameters including CMRR, PSRR, and THD may degrade in the transition region near (V+) – 1.3V; for best results, bias the input within the dominant N-channel or P-channel input stage range as detailed in SBOS106A Section "RAIL-TO-RAIL INPUT".

What is the thermal resistance (θ_JA) of the OPA342UAG4 in its SOIC-8 package?

The OPA342UAG4 in SOIC-8 package has a junction-to-ambient thermal resistance (θ_JA) of 150°C/W, as specified in the SBOS106A datasheet. This value assumes standard JEDEC 2-layer board conditions (1-inch² copper pad). Actual thermal performance improves with additional PCB copper pour or thermal vias - critical for sustained operation near its 150°C max junction temperature limit.

Can the OPA342UAG4 be used with a single 2.5V supply despite its specified minimum of 2.7V?

The OPA342UAG4 is fully specified and guaranteed from 2.7V to 5.5V; operation at 2.5V falls outside its characterized range. While some units may function at 2.5V, parameters including bandwidth, slew rate, output swing, and PSRR are not assured. TI explicitly states "operating voltage range" as 2.5V to 5.5V but qualifies that full specifications apply only from 2.7V - so OPA342UAG4 should not be deployed at 2.5V in production designs without validation.

How does the OPA342UAG4 handle input voltages that go below the negative supply rail?

Input voltages more than 0.3V below V– (e.g., below ground in single-supply use) risk output lock-up. The OPA342UAG4 includes ESD diodes clamping inputs to the rails, but sustained sub-rail voltage requires external protection: a Schottky diode (e.g., IN5818) from input to V– with a 1kΩ series resistor limits current to <10mA, preventing latch-up as shown in SBOS106A Figure 4. This safeguard is mandatory for electret mic biasing or sensor signals with negative excursions.