Texas Instruments OPA388IDGKR

Overview

OPA388IDGKR from Texas Instruments is a precision zero-drift, zero-crossover, true rail-to-rail input/output operational amplifier in an 8-pin VSSOP package. It delivers ±0.25 µV offset voltage, ±0.005 µV/°C drift, 10 MHz gain bandwidth, 7.0 nV/√Hz noise at 1 kHz, and 2 µs settling to 0.01% - enabling high-accuracy signal conditioning in weigh scales and precision ADC driver stages.

For engineers reviewing the OPA388IDGKR datasheet, OPA388IDGKR pinout, OPA388IDGKR application, or OPA388IDGKR equivalent, key selection criteria include ultra-low offset stability over temperature, true RRIO operation with 140-dB CMRR, fast settling without crossover distortion, EMI-filtered inputs, and compatibility with low-voltage (2.5 V to 5.5 V) single-supply systems.

Technical Context

The OPA388IDGKR employs auto-zeroing architecture with chopper stabilization to eliminate 1/f noise and achieve near-zero drift, while its zero-crossover design maintains 140-dB CMRR across full rail-to-rail common-mode range. Its input stage operates down to (V–) – 0.1 V and up to (V+) + 0.1 V, and output swings within 15 mV of rails under no load.

This amplifier supports both single-supply (2.5 V to 5.5 V) and dual-supply (±1.25 V to ±2.75 V) operation, features 100 pA typical input bias current, and drives capacitive loads up to 100 pF while maintaining stability - making it suitable for high-resolution sensor front-ends and precision DAC buffers.

Key Specifications

Pinout & Package

The OPA388IDGKR is housed in an 8-pin VSSOP (DGK) package measuring 3.00 mm × 3.00 mm, with exposed thermal pad for enhanced thermal performance in space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar precision op-amp applications.

Compared with OPA333AIDCKR and LTC2057HMS8#PBF, the OPA388IDGKR uniquely combines VSSOP-8 packaging, 10-MHz bandwidth, zero-crossover behavior, and ±0.25-µV offset - making it optimal for space-constrained, high-speed, high-linearity sensor signal chains requiring minimal calibration.

Availability

OPA388IDGKR is available at Aetrix Electronics and suitable for weigh scale front-ends, lab instrumentation amplifiers, and temperature transmitter designs requiring stable component supply, long-term calibration retention, and industrial temperature range support (–40°C to +125°C).

Supply support for OPA388IDGKR 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 innovation in precision amplifiers and signal chain solutions.

The OPA388IDGKR belongs to TI's OPAx388 zero-drift op-amp family, engineered specifically for high-accuracy DC-critical applications such as sensor signal conditioning, precision data acquisition, and metrology-grade instrumentation.

FAQ

What is the maximum capacitive load the OPA388IDGKR can drive while remaining stable?

The OPA388IDGKR is characterized to drive up to 100 pF capacitive load while maintaining phase margin and avoiding peaking or oscillation, as verified in Figure 6-26 of the SBOS777D datasheet. For loads exceeding 100 pF, external isolation resistor (e.g., 10–50 Ω) between amplifier output and load is recommended to preserve stability without degrading DC accuracy. This capability makes OPA388IDGKR suitable for driving ADC input capacitors and long PCB traces in precision measurement systems.

Does the OPA388IDGKR require external compensation for unity-gain operation?

No, the OPA388IDGKR is internally compensated for stable unity-gain operation across its full specified supply range (2.5 V to 5.5 V) and temperature range (–40°C to +125°C). Its gain bandwidth of 10 MHz and slew rate of 5 V/µs are guaranteed under unity-gain conditions with 10 kΩ load, as confirmed in Section 6.7 of the SBOS777D datasheet. No external components are needed for basic buffer or follower configurations using OPA388IDGKR.

How does the zero-crossover feature of the OPA388IDGKR improve performance in rail-to-rail applications?

The zero-crossover feature ensures continuous, monotonic output behavior across the entire input common-mode range - including near the positive and negative supply rails - by eliminating the traditional "crossover distortion" seen in many rail-to-rail amplifiers. As a result, the OPA388IDGKR maintains 140-dB CMRR even at (V–) – 0.05 V and (V+) + 0.1 V, enabling accurate signal amplification in single-supply systems where input signals approach supply limits, such as in battery-monitoring or sensor-biased circuits using OPA388IDGKR.

Can the OPA388IDGKR operate from a 2.5-V single supply while delivering full rail-to-rail output swing?

Yes, the OPA388IDGKR is fully specified for 2.5-V single-supply operation and delivers true rail-to-rail output swing - sinking and sourcing current to within 15 mV of both rails under no-load conditions, and within 20 mV with 10 kΩ load, as documented in Section 6.7 (Output Voltage Swing) of SBOS777D. Its input common-mode range extends from (V–) – 0.1 V to (V+) + 0.1 V, allowing direct interface with grounded sensors or reference-based signal sources in 2.5-V systems using OPA388IDGKR.

Is the OPA388IDGKR pin-compatible with other members of the OPAx388 family?

No, the OPA388IDGKR (VSSOP-8) is not pin-compatible with the OPA388DBV (SOT-23-5) or OPA388D (SOIC-8), as each variant uses distinct pinouts and terminal counts. The VSSOP-8 (DGK) package has NC pins at positions 1, 5, and 8, whereas the SOIC-8 (D) shares the same 8-pin footprint but assigns different functions to pins 1 and 5. Engineers must verify layout compatibility per package drawing before substituting OPA388IDGKR in existing designs.