Texas Instruments OPA342NA/250

Overview

OPA342NA/250 from Texas Instruments is a single-channel, rail-to-rail input/output CMOS operational amplifier in SOT23-5 package, optimized for low-power, miniature applications operating from 2.7V to 5.5V supply. It delivers 1MHz gain-bandwidth, 1V/µs slew rate, ±6mV max input offset voltage, 150µA typical quiescent current, and output swing within 1mV of rails under light load - ideal for driving sampling ADCs in portable data acquisition systems.

For engineers reviewing the OPA342NA/250 datasheet, OPA342NA/250 pinout, OPA342NA/250 application, or OPA342NA/250 equivalent, key selection criteria include rail-to-rail dynamic range at low supply voltage, THD+N of 0.006% at 1kHz, input bias current below 10pA, and verified stability with ≥250pF capacitive loads in unity-gain configuration.

Technical Context

The OPA342NA/250 employs a complementary differential input stage enabling rail-to-rail common-mode input range extending 300mV beyond both supply rails, with a defined 400mV transition region where PSRR and CMRR degrade. Its class AB output stage achieves 1mV rail-to-rail swing into 100kΩ while maintaining ≥96dB open-loop gain.

Designed for single-supply operation down to 2.5V, it features laser-trimmed offset (±1mV typ), 30µV/√Hz input voltage noise density at 1kHz, and guaranteed performance across –40°C to +85°C with thermal resistance θ_JA = 200°C/W in SOT23-5.

Key Specifications

Pinout & Package

SOT23-5 surface-mount package (DBV drawing), 2.9mm × 1.6mm footprint, 1.45mm height, moisture sensitivity level 2 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA342NA/250, OPA344NA/250 trades 3.5× higher bandwidth for doubled quiescent current, while MCP6001T-E/OT reduces power by 40% but sacrifices rail-to-rail input functionality - making OPA342NA/250 the optimal balance of dynamic range, power, and interface flexibility in miniature low-voltage systems.

Availability

OPA342NA/250 is available at Aetrix Electronics and suitable for portable instrumentation, battery-powered audio interfaces, and space-constrained industrial signal conditioning requiring stable component supply across extended temperature ranges.

Supply support for OPA342NA/250 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 for industrial, automotive, and personal electronics markets.

The OPA342 series belongs to TI's MicroAmplifier™ portfolio, engineered specifically for low-cost, low-power, miniature applications demanding rail-to-rail performance at supply voltages as low as 2.5V.

FAQ

What is the maximum capacitive load the OPA342NA/250 can drive stably in unity-gain configuration?

The OPA342NA/250 is specified to drive up to 250pF of pure capacitive load while maintaining stability in unity-gain configuration. This capability eliminates the need for external compensation in many ADC buffer and filter applications. For loads exceeding 250pF, inserting a 10Ω–20Ω series resistor between the OPA342NA/250 output and the capacitive load improves phase margin without degrading DC accuracy significantly. The OPA342NA/250 datasheet confirms this behavior in the "Capacitive Load and Stability" section.

Does the OPA342NA/250 support true rail-to-rail input operation across its full common-mode range?

Yes, the OPA342NA/250 features a complementary input stage enabling a common-mode input voltage range from –0.3V to (V+) + 0.3V - extending 300mV beyond both supply rails. However, a 400mV transition region exists near (V+) – 1.3V where both N-channel and P-channel input pairs are active, causing temporary degradation in PSRR, CMRR, and THD. For optimal precision, design bias points to avoid this region; the OPA342NA/250 datasheet provides guidance in Figure 3 "Design Optimization with Rail-to-Rail Input Op Amps."

What is the thermal resistance (θ_JA) of the OPA342NA/250 in its SOT23-5 package?

The OPA342NA/250 in SOT23-5 (DBV) package has a junction-to-ambient thermal resistance (θ_JA) of 200°C/W under standard JEDEC PCB mounting conditions. This value assumes a 2-layer board with 1in² copper pad per side connected to the exposed pad (if present) - though the DBV package does not include an exposed thermal pad. Designers should verify board layout and airflow to ensure junction temperature remains below 150°C under worst-case power dissipation (P_D = (V_S × I_Q) + (V_S × I_OUT)).

Can the OPA342NA/250 operate from a 2.5V supply despite its specified minimum of 2.7V?

While the OPA342NA/250 is fully specified and guaranteed over 2.7V to 5.5V, the datasheet states it is "optimized to operate on a single supply as low as 2.5V" with functional performance. At 2.5V, parameters such as GBW, slew rate, and output swing may fall outside guaranteed limits - particularly open-loop gain (A_OL) and CMRR - but basic amplification remains viable. TI recommends verifying critical specs experimentally at 2.5V; the OPA342NA/250 absolute maximum rating allows 7.5V total supply, confirming robustness at low-voltage operation.

How does the OPA342NA/250 handle input voltages that go below the negative supply rail?

The OPA342NA/250 input stage tolerates voltages down to –0.3V relative to V– (ground in single-supply use). If the input drops below this threshold, the output may lock up in an inoperative state. To prevent this, TI recommends adding a Schottky diode clamp (e.g., IN5818) from input to V– with a 1kΩ series resistor limiting current to <10mA - as shown in Figure 4 of the OPA342NA/250 datasheet. This protection is mandatory for signals with negative excursions, such as AC-coupled sensor outputs.