Texas Instruments OPA348AIDR

Overview

OPA348AIDR from Texas Instruments is a single-channel, rail-to-rail input/output CMOS operational amplifier optimized for low-power, single-supply applications. It delivers 1 MHz gain-bandwidth, 45 µA quiescent current, and 0.5 pA input bias current, enabling precision signal conditioning in battery-powered smoke alarms, CO detectors, and medical sensors operating from 2.1 V to 5.5 V.

For engineers reviewing the OPA348AIDR datasheet, OPA348AIDR pinout, OPA348AIDR application, or OPA348AIDR equivalent, key selection criteria include its extended common-mode range (–0.2 V to +5.7 V at 5.5 V supply), 18 mV output swing from rail into 100 kΩ, and validated performance across –40°C to +125°C for industrial and safety-critical sensing systems.

Technical Context

The OPA348AIDR uses a complementary N/P-channel input stage to achieve rail-to-rail input operation with 200 mV beyond both supply rails, though PSRR and offset drift degrade within the (V+)–1.7 V to (V+)–0.9 V transition region. Its class AB output stage supports rail-to-rail output swing, delivering 18 mV from rail into 100 kΩ and 125 mV into 5 kΩ while maintaining >88 dB open-loop gain.

It is unity-gain stable and drives up to 250 pF capacitive loads directly; stability with larger loads is enhanced by adding a 10–20 Ω series resistor at the output or using feedback capacitance in inverting configurations. Input protection requires current limiting to ≤10 mA when voltages exceed supply rails by >0.5 V.

Key Specifications

Pinout & Package

OPA348AIDR is packaged in an 8-pin SOIC (D package), 4.90 mm × 3.91 mm body size, with exposed pad not present and standard JEDEC-compliant footprint.

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, OPA348AIDR uniquely balances ultra-low IQ, rail-to-rail input beyond supplies, and pA-level input bias-making it optimal for battery-powered safety sensors where power, accuracy, and interface flexibility are jointly constrained.

Availability

OPA348AIDR is available at Aetrix Electronics and suitable for smoke alarm manufacturing, portable medical device production, and industrial sensor module development requiring stable component supply across long product lifecycles.

Supply support for OPA348AIDR 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 amplifiers and low-power signal chains.

The OPAx348 product line was designed specifically for ultra-low-power, single-supply sensor signal conditioning in safety-critical and portable applications-emphasizing rail-to-rail operation, nanoscale input bias, and extended temperature reliability.

FAQ

What is the maximum capacitive load the OPA348AIDR can drive in unity-gain configuration?

The OPA348AIDR can directly drive up to 250 pF of pure capacitive load while maintaining stability in unity-gain buffer configuration. For loads exceeding this, a 10–20 Ω series resistor at the output improves phase margin without degrading DC accuracy-critical when interfacing with ADC input capacitance or long PCB traces. This capability is verified in TI's SBOS213H datasheet Figure 13 and Section 7.3.5.

Does the OPA348AIDR support input voltages below ground or above V+?

Yes-the OPA348AIDR features a rail-to-rail input stage that operates from (V−) − 0.2 V to (V+) + 0.2 V, allowing inputs 200 mV beyond both supply rails. However, absolute maximum ratings limit input voltage to (V−) − 0.5 V and (V+) + 0.5 V, and input current must be limited to ≤10 mA if exceeding the common-mode range. This behavior is documented in Section 7.3.3 of the OPA348AIDR datasheet.

What is the typical output voltage swing of the OPA348AIDR into a 100 kΩ load?

At 25°C and with a 5 V supply, the OPA348AIDR delivers a typical output swing within 18 mV of each rail into a 100 kΩ load-i.e., from 18 mV above GND to 4.982 V. This rail-to-rail performance is confirmed in Electrical Characteristics Table 6.7 (Output section) and Typical Characteristics Figure 6 of the SBOS213H datasheet, ensuring full utilization of 12-bit ADCs like ADS7822.

Is the OPA348AIDR suitable for driving the ADS7822 12-bit ADC?

Yes-the OPA348AIDR is explicitly recommended in TI's application circuit for the ADS7822, where it conditions electret microphone signals prior to conversion. Its 1 MHz bandwidth, 45 µA IQ, rail-to-rail output, and ability to drive the ADS7822's input capacitance make it a validated front-end solution. The reference schematic (page 16, Figure 25) shows OPA348AIDR configured as a gain-of-100 amplifier with RC filtering for anti-aliasing.

What package variants does the OPA348AIDR come in, and what does 'AIDR' signify?

The 'AIDR' suffix denotes the 8-pin SOIC (D package) variant of the OPA348, with body size 4.90 mm × 3.91 mm. Other variants include OPA348AIDBVR (SOT-23-5) and OPA348AIDCKR (SC70-5). All share identical electrical specifications; only package dimensions and thermal resistance differ-RθJA is 142°C/W for OPA348AIDR versus 229°C/W for the SOT-23 version (Section 6.4).