Texas Instruments OPA4322SAIPWR

Overview

OPA4322SAIPWR from Texas Instruments is a quad-channel, rail-to-rail input/output CMOS operational amplifier optimized for low-power, single-supply signal conditioning. It delivers 20 MHz gain bandwidth, 10 V/μs slew rate, 8.5 nV/√Hz input voltage noise at 1 kHz, 1.4–1.65 mA per channel quiescent current, and operates from 1.8 V to 5.5 V - enabling high-fidelity audio and precision sensor front-ends in space-constrained industrial and portable systems.

For engineers reviewing the OPA4322SAIPWR datasheet, OPA4322SAIPWR pinout, OPA4322SAIPWR application, or OPA4322SAIPWR equivalent, key selection considerations include its shutdown-enabled quad architecture, TSSOP-16 package thermal performance (R_θJA = 105.9°C/W), rail-to-rail I/O swing within 20 mV of rails, and verified operation across –40°C to +125°C.

Technical Context

The OPA4322SAIPWR integrates four independent amplifiers sharing a common supply domain, each featuring unity-gain stability, zero-crossover rail-to-rail input stage (eliminating distortion near supply rails), and active shutdown control with <0.1 µA per-channel quiescent current. Its CMOS input stage provides ultra-low input bias current (±0.2 pA typ at 25°C) and high input impedance (>10¹³ Ω), critical for high-impedance sensor interfaces.

Designed for single-supply operation, it supports common-mode input range from (V–) – 0.1 V to (V+) + 0.1 V and output swing to within 20 mV of both rails under 10 kΩ load. The device's 20-MHz GBP and 10-V/μs slew rate support stable closed-loop configurations up to G = +100 without external compensation.

Key Specifications

Pinout & Package

Packaged in a 16-pin TSSOP (PW), the OPA4322SAIPWR measures 5.00 mm × 4.40 mm with exposed thermal pad on underside (not electrically connected). Pin 1 is OUT A; pins 8 and 9 are SHDN A/B and SHDN C/D (active-low, shared per pair); pin 13 is V–; pin 4 is V+.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA4322SAIPWR, OPA4316IPWR trades bandwidth and noise for lower quiescent current and cost, while LMV844QMA/NOPB offers automotive qualification at the expense of precision and power efficiency - making OPA4322SAIPWR optimal for high-performance industrial and portable designs requiring configurable power states.

Availability

OPA4322SAIPWR is available at Aetrix Electronics and suitable for medical sensor front-ends, portable audio line drivers, and industrial process controller input stages requiring stable component supply, long-term manufacturability, and guaranteed traceable sourcing.

Supply support for OPA4322SAIPWR 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 OPAx322x product line was designed specifically for low-noise, rail-to-rail, single-supply operational amplifier applications demanding high bandwidth, precision, and power efficiency - targeting sensor signal conditioning, consumer audio, and multi-pole active filtering.

FAQ

What is the maximum capacitive load the OPA4322SAIPWR can drive without instability?

The OPA4322SAIPWR is specified to drive up to 50 pF capacitive load while maintaining stability and phase margin ≥47° at unity gain. For loads exceeding 50 pF, external series resistance (e.g., 10–50 Ω) at the output is recommended to isolate the capacitance and preserve transient response and THD+N performance. This capability enables direct interface to ADC inputs and long PCB traces without additional compensation components.

Does the OPA4322SAIPWR support true rail-to-rail input and output operation?

Yes, the OPA4322SAIPWR supports rail-to-rail input common-mode voltage from (V–) – 0.1 V to (V+) + 0.1 V and rail-to-rail output swing to within 20 mV of both supply rails under 10-kΩ load. Its zero-crossover input stage eliminates distortion at mid-supply transitions, ensuring linear behavior across the full input range - critical for precision single-supply applications like sensor interfacing and audio buffering.

How does the shutdown function operate on the OPA4322SAIPWR?

The OPA4322SAIPWR features two active-low shutdown pins: SHDN A/B (pin 8) and SHDN C/D (pin 9). Asserting SHDN A/B disables channels A and B; asserting SHDN C/D disables channels C and D. When both are low, total quiescent current drops to ≤0.5 µA (0.1 µA per channel). Enable time is 10 µs for full shutdown and 6 µs for partial shutdown, supporting rapid power-state transitions in responsive systems.

What is the typical input bias current of the OPA4322SAIPWR over temperature?

The OPA4322SAIPWR exhibits ultra-low input bias current: ±0.2 pA typical at 25°C, rising to ±400 pA maximum across –40°C to +125°C. This CMOS-input performance minimizes voltage errors in high-impedance circuits (e.g., >100 MΩ sensor sources), making it suitable for precision applications such as pH measurement, photodiode amplification, and piezoelectric signal conditioning where leakage currents would otherwise dominate error budgets.

Is the OPA4322SAIPWR pin-compatible with other devices in the OPAx322x family?

No, the OPA4322SAIPWR (TSSOP-16) is not pin-compatible with the non-S variants (e.g., OPA4322IPWR, TSSOP-14) due to differing pin counts and shutdown functionality. The 'S' suffix denotes integrated shutdown, requiring dedicated SHDN A/B and SHDN C/D pins (pins 8 and 9) absent in the 14-pin version. Layout changes are required when substituting between OPA4322SAIPWR and OPA4322IPWR.