Texas Instruments REF2940AIDBZT

Overview

REF2940AIDBZT 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, 50 µA max quiescent current, and 1 mV min dropout voltage. It serves as a stable, low-power reference for high-resolution ADCs and portable instrumentation requiring tight voltage stability across –40°C to 125°C.

For engineers reviewing the REF2940AIDBZT datasheet, REF2940AIDBZT pinout, REF2940AIDBZT application, or REF2940AIDBZT equivalent, key selection criteria include output voltage tolerance, thermal drift performance, load regulation (≤100 µV/mA), dropout behavior under 25 mA load, and compatibility with capacitive loads without external compensation.

Technical Context

The REF2940AIDBZT implements a curvature-compensated band-gap topology using two bipolar transistors with mismatched current densities and a resistor network to sum positive and negative temperature coefficients-achieving near-zero net drift. Its CMOS design enables ultra-low quiescent current (42–59 µA) with minimal supply sensitivity.

It operates in series mode with no mandatory output capacitor, remains stable with any capacitive load, and supports input voltages as low as V_OUT + 50 mV at full 25 mA load. 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, 3-pin surface-mount, lead-free and RoHS compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADR3440ARMZ and MAX6126A41+T, REF2940AIDBZT trades absolute accuracy and drift for higher output current, lower quiescent current, and smaller footprint - making it optimal for cost-sensitive, space-constrained, battery-operated systems where ±2% and 100 ppm/°C meet system-level requirements.

Availability

REF2940AIDBZT is available at Aetrix Electronics and suitable for portable instrumentation, medical monitoring devices, and industrial data acquisition systems requiring stable component supply with guaranteed long-term sourcing.

Supply support for REF2940AIDBZT 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 company specializing in analog and embedded processing technologies, with leadership in precision analog ICs and power management solutions.

The REF29xx family was designed specifically for low-power, high-accuracy voltage referencing in portable and battery-operated systems - emphasizing minimal dropout, ultra-low IQ, and robust thermal performance in micro packages.

FAQ

What is the minimum input voltage required for stable operation of REF2940AIDBZT?

The REF2940AIDBZT requires a minimum input voltage of V_OUT + 50 mV (i.e., 4.146 V) when delivering 25 mA load current. In unloaded conditions, it operates with as little as 1 mV headroom (4.097 V). This ultra-low dropout enables use with tightly regulated 4.2 V Li-ion batteries or post-LDO rails where margin is constrained. The REF2940AIDBZT maintains regulation down to this threshold across –40°C to 125°C.

Does REF2940AIDBZT require an output capacitor for stability?

No, REF2940AIDBZT does not require an output capacitor and is stable with any capacitive load - including zero capacitance. Unlike many references, its internal compensation eliminates the need for external stabilization components. However, TI recommends a 0.47 µF ceramic bypass capacitor at the IN pin to suppress supply noise. Adding output capacitance may reduce high-frequency noise but is never mandatory for stability.

What is the long-term stability performance of REF2940AIDBZT?

REF2940AIDBZT exhibits 24 ppm typical drift over the first 1000 hours and 15 ppm over the subsequent 1000 hours (hours 1000–2000), measured across 30 units. This corresponds to approximately ±0.1 mV total drift after 2000 hours of continuous operation at 25°C. Long-term stability improves with time and is characterized under controlled burn-in conditions - critical for applications requiring multi-year calibration intervals without field adjustment.

How does REF2940AIDBZT perform under varying temperature conditions?

REF2940AIDBZT is specified for –40°C to 125°C operation with maximum temperature drift of 100 ppm/°C using the box method. Typical drift is 50 ppm over this range. Output voltage shifts linearly within spec: e.g., at 125°C, deviation is ≤±0.51 mV from 25°C value. Thermal hysteresis is ≤100 ppm after cycling - ensuring repeatable performance after thermal stress. These characteristics make REF2940AIDBZT suitable for automotive under-hood and industrial control environments.

Can REF2940AIDBZT drive a 24-bit ADC reference input directly?

Yes, REF2940AIDBZT can directly drive most 24-bit ADC reference inputs, including those of the AD7793 and ADS1256, which typically draw <100 µA. With 25 mA output capability and low output impedance (<1 Ω at DC), it easily handles dynamic current demands during conversion cycles. Its 45 µV_PP (0.1–10 Hz) noise contributes <0.3 LSB error to a 24-bit 4.096 V full-scale system - well within acceptable limits for high-fidelity measurement. REF2940AIDBZT's performance is validated in TI reference designs for precision data acquisition.