Texas Instruments OPA2338UA/2K5G4

Overview

OPA2338UA/2K5G4 from Texas Instruments is a dual, rail-to-rail output CMOS operational amplifier optimized for gain ≥5, featuring 12.5MHz gain-bandwidth product, 4.6V/µs slew rate, 525µA per amplifier quiescent current, and operation from 2.5V to 5.5V single supply - used in precision signal conditioning for battery-powered test equipment and photodiode pre-amplification.

For engineers reviewing the OPA2338UA/2K5G4 datasheet, OPA2338UA/2K5G4 pinout, OPA2338UA/2K5G4 application, or OPA2338UA/2K5G4 equivalent, key selection criteria include minimum stable gain (G ≥ 5), SOT23-8 or SOIC-8 package compatibility, rail-to-rail output swing down to 125mV from rails, FET-input bias current ≤10pA, and low-noise performance (26nV/√Hz) in space-constrained analog front-ends.

Technical Context

The OPA2338UA/2K5G4 implements a high-speed, unity-gain unstable CMOS op amp architecture requiring closed-loop gain ≥5 for stability, with dominant-pole compensation shifted to ~3MHz to enable 12.5MHz bandwidth at G = 5. Its input stage uses p-channel JFET-like transistors delivering 10pA max input bias current and rail-inclusive common-mode range (−0.2V to V+ − 1.2V).

Each amplifier operates independently with no crosstalk, supporting simultaneous signal paths in dual-channel systems. Output stage delivers rail-to-rail swing with 125mV headroom into 25kΩ at AOL ≥ 100dB, while maintaining 0.0035% THD+N at 1kHz, 3VPP output under G = 5 conditions.

Key Specifications

Pinout & Package

OPA2338UA/2K5G4 is packaged in SOIC-8 (Package Designator: D), a surface-mount 8-pin small-outline integrated circuit with 1.27mm pitch, 3.9mm width, and 4.9mm length - suitable for automated assembly and moderate-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual CMOS op amp applications.

Compared with OPA2337UA/2K5 and MCP6022-I/SN, OPA2338UA/2K5G4 delivers the highest bandwidth-slew rate combination (12.5MHz/4.6V/µs) for gain ≥5 signal chains, making it optimal for high-fidelity, medium-speed data acquisition where speed outweighs ultra-low IQ requirements.

Availability

OPA2338UA/2K5G4 is available at Aetrix Electronics and suitable for battery-powered instruments, photodiode pre-amplifiers, and medical sensors requiring stable component supply with guaranteed long-term availability and consistent parametric performance.

Supply support for OPA2338UA/2K5G4 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 over 90 years of innovation in precision amplifiers and power management ICs.

The OPA2338UA/2K5G4 belongs to TI's MicroAmplifier™ series, designed specifically for miniature, low-power, high-accuracy analog signal conditioning in space- and energy-constrained applications.

FAQ

What is the minimum stable gain for OPA2338UA/2K5G4?

The OPA2338UA/2K5G4 is optimized for closed-loop gains greater than or equal to 5. It is not unity-gain stable; using it at G < 5 without external compensation risks instability and oscillation. Compensation techniques - such as adding a capacitor in the feedback network - are documented in the datasheet for unity-gain or low-gain configurations. Always verify phase margin with simulation or bench testing when deviating from G ≥ 5.

Does OPA2338UA/2K5G4 support true rail-to-rail input?

No, the OPA2338UA/2K5G4 provides rail-to-rail *output* swing but not rail-to-rail *input*. Its input common-mode voltage range extends from (V−) − 0.2V to (V+) − 1.2V. This means the inputs cannot accept signals at the positive rail (V+) or slightly beyond ground (V−) without violating specifications. For true rail-to-rail input capability, consider TI's OPA2322 or OPA2376 families.

What package type and marking does OPA2338UA/2K5G4 use?

OPA2338UA/2K5G4 is supplied in an SOIC-8 package (Package Designator: D), with tape-and-reel packaging (2500 units per reel). The device marking on the top of the package is "OPA 2338UA", printed in two lines. This matches TI's standard SOIC-8 mechanical dimensions (4.9mm × 3.9mm × 1.75mm height) and is compatible with industry-standard reflow profiles (MSL Level-2-260°C-1 year).

Can OPA2338UA/2K5G4 drive capacitive loads directly?

OPA2338UA/2K5G4 can drive moderate capacitive loads (≤100pF) without external compensation, as verified in typical characteristics (Figure 7 shows stable step response with CL = 100pF). For loads >100pF - such as ADC input capacitors or long PCB traces - isolation resistance (e.g., 10–50Ω in series with output) or feedback capacitor compensation is recommended to maintain phase margin and prevent peaking or oscillation.

How does OPA2338UA/2K5G4 compare to OPA2337UA/2K5 in terms of power supply rejection?

Both OPA2338UA/2K5G4 and OPA2337UA/2K5 specify 125µV/V (118dB) PSRR at DC and low frequencies, with degradation above 10kHz. Measured PSRR remains ≥74dB up to 100kHz for both devices. No meaningful PSRR difference exists between the two families - their CMOS processes and supply rejection architectures are functionally identical; the primary distinction lies in gain-bandwidth and stability optimization, not supply noise immunity.