Texas Instruments REF2940AIDBZRG4

Overview

REF2940AIDBZRG4 from Texas Instruments is a precision 4.096 V CMOS band-gap voltage reference in a 3-pin SOT-23 package, delivering ±2% initial accuracy, 100 ppm/°C max temperature drift, and 50 µA max quiescent current. It supports 25 mA output current with only 1 mV dropout under no-load conditions and operates across –40°C to 125°C for high-reliability data acquisition and portable instrumentation.

For engineers reviewing the REF2940AIDBZRG4 datasheet, REF2940AIDBZRG4 pinout, REF2940AIDBZRG4 application, or REF2940AIDBZRG4 equivalent, this page delivers verified electrical specifications, thermal behavior, load regulation performance, and real-world implementation guidance for low-power, high-accuracy analog systems.

Technical Context

The REF2940AIDBZRG4 implements a curvature-compensated band-gap topology using two transistors (Q1, Q2) biased at different current densities to generate a PTAT voltage across R1, which is amplified and summed with the CTAT base-emitter voltage of Q2-yielding a stable 4.096 V output. Its CMOS architecture enables ultra-low IQ and inherent stability without mandatory output capacitance.

It achieves 45 µVPP (0.1–10 Hz) and 128 µVrms (10 Hz–10 kHz) noise performance, supports force-and-sense load regulation measurement, and exhibits 24 ppm long-term drift over 0–1000 hours. Thermal hysteresis is specified at ≤100 ppm after cycling from –40°C to 125°C and back to 25°C.

Key Specifications

Pinout & Package

SOT-23 (DBZ) package, 2.92 mm × 1.30 mm body size, 3-pin surface-mount configuration with gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage reference applications.

Compared with REF3040AIDBZR and ADR3440ARJZ-R7, REF2940AIDBZRG4 delivers the lowest quiescent current (50 µA) and lowest cost per unit while maintaining sufficient accuracy and drift for portable and industrial data acquisition-making it the optimal balance of power, precision, and price in volume production.

Availability

REF2940AIDBZRG4 is available at Aetrix Electronics and suitable for portable instrumentation, industrial data acquisition systems, and medical monitoring devices requiring stable component supply with guaranteed long-term continuity.

Supply support for REF2940AIDBZRG4 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 expertise in precision voltage references and low-power signal-chain solutions.

The REF29xx family was designed specifically for battery-powered and space-constrained applications demanding ultra-low IQ, low dropout, and robust thermal performance across extended industrial temperatures.

FAQ

What is the minimum input voltage required for REF2940AIDBZRG4 to regulate properly?

The REF2940AIDBZRG4 requires a minimum input voltage of VOUT + 1 mV (i.e., 4.097 V) under no-load conditions. With 25 mA load, the minimum supply rises to VOUT + 50 mV (4.146 V). This ultra-low dropout enables direct operation from 4.2 V Li-ion cells without intermediate regulation, preserving system efficiency and board space.

Does REF2940AIDBZRG4 require an output capacitor for stability?

No, REF2940AIDBZRG4 is internally compensated and stable with any capacitive load-including zero capacitance. Unlike many references, it does not require an output capacitor for phase margin or transient response. However, a 0.47 µF ceramic bypass capacitor on the IN pin is recommended to suppress supply noise and improve PSRR.

How does the 100 ppm/°C temperature drift of REF2940AIDBZRG4 impact 16-bit ADC accuracy?

Over a –40°C to 125°C range, the 100 ppm/°C drift introduces up to ±41 ppm (±168 µV) error in the 4.096 V output. For a 16-bit ADC with full-scale 4.096 V, that equals ±1.06 LSB-well within typical system tolerances for industrial DAQ and portable test equipment where end-point calibration is performed at room temperature.

Can REF2940AIDBZRG4 drive a 25 mA load continuously across its full temperature range?

Yes, REF2940AIDBZRG4 is rated for 25 mA continuous output current from –40°C to 125°C. Its thermal design (RθJA = 297.3°C/W) and low power dissipation (max 128 mW at 5.5 V/25 mA) ensure safe operation without derating in standard PCB layouts with adequate copper area, making it suitable for driving multiple op-amps or ADC references simultaneously.

What is the long-term stability behavior of REF2940AIDBZRG4 over 2000 hours of operation?

REF2940AIDBZRG4 exhibits 24 ppm drift over the first 1000 hours and an additional 15 ppm over the next 1000 hours (total 39 ppm at 2000 hrs), based on characterization of 30 units. This predictable aging profile supports reliable calibration scheduling in field-deployed medical and industrial instruments where recalibration intervals exceed 12 months.