Texas Instruments OPA2340PA

Overview

OPA2340PA from Texas Instruments is a dual-channel, rail-to-rail input/output CMOS operational amplifier optimized for single-supply, low-voltage operation (2.7 V to 5.5 V). It delivers 5.5 MHz gain-bandwidth, 6 V/µs slew rate, and output swing within 1 mV of rails under 100-kΩ load - enabling high-fidelity signal conditioning in A/D converter driver and audio front-end applications.

For engineers reviewing the OPA2340PA datasheet, OPA2340PA pinout, OPA2340PA application, or OPA2340PA equivalent, key selection criteria include rail-to-rail I/O performance at 2.7 V, low 750 µA/channel quiescent current, 0.0007% THD+N at 1 kHz, and verified compatibility with sampling ADCs like ADS7816 in noninverting configurations.

Technical Context

The OPA2340PA uses a complementary CMOS input stage (N- and P-channel parallel pairs) to achieve rail-to-rail input common-mode range extending 500 mV beyond both supply rails. Its class AB output stage enables millivolt-level rail approach under light loads while maintaining >106 dB open-loop gain at DC.

It operates stably in unity-gain configuration driving up to 1000 pF capacitive loads and supports fast settling (1 µs to 0.1%) - critical for driving medium-speed sampling ADCs such as the 12-bit ADS7816 without charge injection artifacts.

Key Specifications

Pinout & Package

OPA2340PA is packaged in an 8-pin PDIP (Plastic Dual In-line Package) with body size 9.81 mm × 6.35 mm, suited for through-hole prototyping and legacy industrial PCBs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-rail-to-rail op-amp applications.

Compared with OPA2340UA and MCP6022-I/SN, the OPA2340PA uniquely combines through-hole PDIP packaging, guaranteed 1-mV rail-to-rail output, and 750 µA/channel quiescent current - making it optimal for legacy industrial designs requiring serviceability and micro-power precision.

Availability

OPA2340PA is available at Aetrix Electronics and suitable for industrial process control, portable data acquisition, and audio front-end applications requiring stable component supply and long-term obsolescence management.

Supply support for OPA2340PA 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 90 years of innovation in precision analog ICs.

The OPA2340PA belongs to TI's MicroAmplifier™ series, designed specifically for low-voltage, single-supply signal conditioning in space- and power-constrained systems - emphasizing rail-to-rail performance, low distortion, and robust ADC driving capability.

FAQ

What is the minimum supply voltage for reliable operation of the OPA2340PA?

The OPA2340PA is fully specified from 2.7 V and operates reliably down to 2.5 V. At 2.5 V, rail-to-rail input and output functionality remains intact, though small-signal bandwidth reduces slightly. The device maintains >106 dB open-loop gain and 0.0007% THD+N performance across the full 2.5–5.5 V range, as confirmed in the SBOS073C datasheet Section 6.3 and Figure 17.

Can the OPA2340PA drive the ADS7816 12-bit ADC directly without external components?

Yes - the OPA2340PA can directly drive the ADS7816 in noninverting configuration, as shown in Figure 26 of the SBOS073C datasheet. Its 6 V/µs slew rate and 1-µs 0.1% settling time meet ADS7816's sampling timing requirements. A 0.1-µF bypass capacitor on each supply pin is mandatory; no series resistor or RC filter is required for basic operation, though one may be added for noise filtering per application needs.

Does the OPA2340PA support true rail-to-rail output with 10-kΩ load?

No - the OPA2340PA achieves output swing within 10 mV of the rails with a 10-kΩ load (per Section 6.7, "Voltage output swing from rail"), versus 1 mV with 100-kΩ. This 10-mV limitation still provides >99% of full-scale range for 5-V systems, preserving 11+ effective bits when driving 12-bit ADCs. Performance degrades to 40 mV at 2-kΩ, as verified in the Electrical Characteristics table.

What is the input bias current specification for the OPA2340PA, and how does it affect high-impedance sensor interfaces?

The OPA2340PA has a typical input bias current of ±0.2 pA at 25°C (max ±10 pA over temperature), due to its CMOS input stage. When interfacing with high-Z sources (e.g., pH electrodes or piezoelectric sensors), this ultra-low bias current minimizes voltage drop across source impedances up to 1 GΩ, avoiding significant DC errors. Layout best practices (guard traces, clean PCB) are recommended to maintain this performance in production.

Is the OPA2340PA pin-compatible with other dual op-amps in PDIP-8 packages?

No - the OPA2340PA uses a nonstandard PDIP-8 pinout optimized for dual independent amplifiers (V– on pin 4, V+ on pin 8), differing from industry-standard dual op-amps like LM358 (V+ on pin 8, V– on pin 4, but shared supply pins). Direct replacement requires PCB layout revision. Always verify pin functions against the "Pin Functions: OPA2340" table in SBOS073C Section 5 before substitution.