Texas Instruments OPA2378AIDCNT

Overview

OPA2378AIDCNT from Texas Instruments is a dual, rail-to-rail input/output, zero-drift precision operational amplifier optimized for low-noise, low-power, single-supply sensor signal conditioning. It delivers 20 µV max input offset voltage, 0.1 µV/°C offset drift, 20 nV/√Hz voltage noise density at 1 kHz, 900 kHz gain-bandwidth, and 125 µA quiescent current per amplifier - enabling high-accuracy measurements in portable medical devices and battery-powered instrumentation.

For engineers reviewing the OPA2378AIDCNT datasheet, OPA2378AIDCNT pinout, OPA2378AIDCNT application, or OPA2378AIDCNT equivalent, key selection criteria include its flicker-noise-free architecture, EMI-filtered inputs, ±10 mA input current tolerance, rail-to-rail output swing within 6 mV of rails (RL = 10 kΩ), and guaranteed operation from –40°C to +125°C in SOT23-8 packaging.

Technical Context

The OPA2378AIDCNT employs proprietary auto-calibration every 3 µs to eliminate 1/f noise and maintain ultra-low offset drift, using a time-continuous 350 kHz core amplifier. Its internal EMI filter provides 29 dB rejection at 800 MHz with a –3 dB cutoff near 25 MHz, suppressing RF rectification effects on dc accuracy.

It supports unity-gain stable operation with rail-to-rail input common-mode range extending 50 mV beyond supplies and output swing to within 6 mV of rails. PSRR is 1.5 µV/V typical, enabling direct battery operation without regulation across 2.2 V to 5.5 V supply range.

Key Specifications

Pinout & Package

SOT23-8 package (DCN designation), 2.9 mm × 1.6 mm footprint, 1.45 mm height, thermal resistance θ_JA = 100 °C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with OPA2333AIDR and AD8628ARZ-REEL7, the OPA2378AIDCNT uniquely balances ultra-low 0.1–10 Hz noise (0.4 µV_PP), integrated EMI filtering, and micro-power operation (125 µA) - making it optimal for battery-powered medical sensors requiring both precision and robustness.

Availability

OPA2378AIDCNT is available at Aetrix Electronics and suitable for portable medical devices, battery-powered instrumentation, and sensor signal conditioning requiring stable component supply across automotive, industrial, and healthcare OEM programs.

Supply support for OPA2378AIDCNT 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 deep expertise in precision signal chain design.

The OPA2378AIDCNT belongs to TI's Zerø-Drift Series, engineered specifically for high-accuracy, low-power, single-supply applications including glucose meters, weigh scales, and thermopile interfaces where long-term offset stability and EMI resilience are mandatory.

FAQ

What is the maximum capacitive load the OPA2378AIDCNT can drive without instability?

The OPA2378AIDCNT is characterized to drive up to 100 pF capacitive loads while maintaining phase margin >45°, as verified in Figure 18 of the SBOS417D datasheet. For loads exceeding 100 pF, an isolation resistor (typically 10–50 Ω) should be placed in series with the output to preserve stability. This capability enables direct interface to ADC input capacitors and long PCB traces in portable medical designs without added buffering.

Does the OPA2378AIDCNT require external components for ESD protection?

No - the OPA2378AIDCNT integrates robust ESD protection with Human Body Model (HBM) rating of 4000 V, Charged Device Model (CDM) of 1000 V, and Machine Model (MM) of 200 V. Its internal structure includes current-steering diodes and edge-triggered absorption circuits on all pins, as shown in Figure 30 of SBOS417D. External protection is unnecessary unless operating in extreme industrial ESD environments (>15 kV).

Can the OPA2378AIDCNT operate from a 2.2 V single supply while driving a 10 kΩ load rail-to-rail?

Yes - the OPA2378AIDCNT guarantees rail-to-rail output swing to within 6 mV of both rails with RL = 10 kΩ at VS = 2.2 V, as specified in the "Output" section of the Electrical Characteristics table. At 25°C, typical swing is 3 mV from each rail, enabling full-scale utilization of low-voltage ADCs like the ADS1115 in energy-harvesting sensor nodes.

How does the auto-calibration circuit affect power-up behavior of the OPA2378AIDCNT?

Upon power-up, the OPA2378AIDCNT requires approximately 100 µs to achieve specified 20 µV offset accuracy, as the internal 350 kHz core amplifier completes initial zeroing cycles. During this interval, output may exhibit transient settling; system timing must allow ≥100 µs stabilization before sampling. This behavior is documented in the "Internal Offset Correction" section of SBOS417D and is independent of supply ramp rate.

Is the OPA2378AIDCNT suitable for driving the reference input of a 16-bit SAR ADC?

Yes - the OPA2378AIDCNT's low output impedance (<1 Ω at dc, <10 Ω up to 100 kHz), 0.4 µV_PP 0.1–10 Hz noise, and rail-to-rail swing make it ideal for buffering precision voltage references (e.g., REF3330) into ADC reference pins. Its 125 µA quiescent current avoids loading low-power references, and channel separation >135 dB prevents digital switching noise from coupling into the reference path.