Analog Devices Inc./Maxim Integrated MAX6138BEXR30+T

Overview

MAX6138BEXR30+T from Maxim Integrated is a precision two-terminal shunt-mode bandgap voltage reference with a fixed 3.000V reverse breakdown voltage, 0.2% initial accuracy, 25ppm/°C max temperature coefficient, and operation over –40°C to +85°C. It delivers stable regulation across 60μA–15mA shunt current and is used in high-accuracy analog signal chains of portable instrumentation and battery-powered data acquisition systems.

For engineers reviewing the MAX6138BEXR30+T datasheet, MAX6138BEXR30+T pinout, MAX6138BEXR30+T application, or MAX6138BEXR30+T equivalent, key selection criteria include shunt-current range compatibility, SC70-3 footprint constraints, 3.0V output tolerance at temperature extremes, and low-noise performance in low-power sensor interfaces.

Technical Context

The MAX6138BEXR30+T implements a laser-trimmed bandgap core in BiCMOS process to achieve precise 3.000V reverse breakdown with guaranteed 0.2% initial accuracy and ±25ppm/°C TC over –40°C to +85°C. Its two-terminal architecture eliminates need for external biasing circuitry beyond a series resistor (RS), simplifying integration into space-constrained designs.

It maintains stable regulation without output capacitors and remains stable with any capacitive load up to 1µF. Dynamic impedance is ≤0.8Ω at 1mA, and wideband noise is 45µVRMS (10Hz–10kHz), enabling use in high-resolution ADC references and precision DAC buffers.

Key Specifications

Pinout & Package

Package: SC70-3 (1.8mm × 1.8mm, 0.95mm height), RoHS-compliant, moisture-sensitive level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4040C30IDCKR, MAX6138BEXR30+T offers 2.5× better temperature stability and 50% smaller footprint; compared with ADR3430ARJZ-R7, it supports 40% lower minimum operating current (60μA vs. 100μA), enabling deeper sleep-state regulation in energy-harvesting systems.

Availability

MAX6138BEXR30+T is available at Aetrix Electronics and suitable for portable instrumentation, industrial sensor transmitters, and medical wearable electronics requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6138BEXR30+T 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

Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and power management ICs for demanding industrial, medical, and communications applications.

The MAX6138 family delivers high-accuracy, low-drift shunt references in ultra-compact SC70 packages for space- and power-constrained systems where traditional three-terminal references are impractical.

FAQ

What is the guaranteed initial accuracy of MAX6138BEXR30+T?

The MAX6138BEXR30+T is specified with ±0.2% initial accuracy at +25°C, verified across production lots using laser-trimmed resistors. This grade (B) ensures 3.000V output falls within 2.994V–3.006V at room temperature, supporting single-point calibration in production test flows without trimming.

Does MAX6138BEXR30+T require an external output capacitor?

No, MAX6138BEXR30+T does not require an external output capacitor and remains stable with any capacitive load from 0 to 1µF. This eliminates BOM cost, layout complexity, and reliability risks associated with capacitor aging or ESR variation in the reference path.

What is the minimum shunt current needed for regulation in MAX6138BEXR30+T?

The MAX6138BEXR30+T requires a minimum shunt current of 60μA to maintain regulation across its full temperature range (–40°C to +85°C). At –40°C, the device guarantees regulation down to 65μA per datasheet Electrical Characteristics table for the 3.0V variant.

Can Pin 3 of MAX6138BEXR30+T be left unconnected?

Yes, Pin 3 of MAX6138BEXR30+T is marked N.C. (No Connection) and must be left floating or connected to Pin 2 (–). It has no internal bond; connecting it elsewhere may introduce leakage or instability. The SC70-3 package uses only Pins 1 and 2 for functional operation.

How does MAX6138BEXR30+T compare to LM4040 in size and performance?

MAX6138BEXR30+T is offered in the 1.8mm × 1.8mm SC70-3 package - 50% smaller than the SOT23-3 package used by LM4040 - while delivering superior 0.2% initial accuracy and 25ppm/°C temperature coefficient versus LM4040's typical 0.5% and 100ppm/°C, making it suitable for next-generation miniaturized systems.