Analog Devices Inc./Maxim Integrated MAX6191CESA

Overview

MAX6191CESA from Maxim Integrated is a precision, micropower, low-dropout series-mode bandgap voltage reference delivering 2.048V output with ±10mV initial accuracy, 10ppm/°C max temperature coefficient, and 35µA max quiescent supply current. It operates from 2.5V to 12.6V input, supports ±500µA load current, and is used in high-accuracy ADC/DAC biasing and portable instrumentation where stable low-power reference is critical.

For engineers reviewing the MAX6191CESA datasheet, MAX6191CESA pinout, MAX6191CESA application, or MAX6191CESA equivalent, key selection factors include its 2.048V nominal output optimized for 12-bit systems, guaranteed capacitive-load stability up to 2.2nF, dropout voltage of ≤100mV at 500µA, and ±2mV typical initial error over temperature - all validated across -40°C to +85°C.

Technical Context

The MAX6191CESA employs a proprietary curvature-correction circuit and laser-trimmed thin-film resistors to achieve <5ppm/°C typical temperature coefficient and <0.5% total error over temperature and load. Its series-mode architecture enables bidirectional output current (±500µA) without external components while maintaining immunity to input voltage variation (0.8µA/V supply current drift).

Internally compensated for fast settling (30µs to 0.1%), it remains stable with capacitive loads from 0 to 2.2nF and exhibits 84dB ripple rejection at 120Hz. Line regulation is 10µV/V max, and load regulation is 0.12µV/µA - enabling direct use in precision data converters without post-regulation filtering.

Key Specifications

Pinout & Package

MAX6191CESA is housed in an 8-pin SO (Small Outline) package, RoHS-compliant and rated for -40°C to +85°C operation. Pin 1 (OUT), Pin 2 (IN), Pin 4 (GND), and Pins 1/3/5/7/8 (N.C.) are defined per Maxim's official pin configuration diagram.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6191BESA+, MAX6191CESA trades ±5mV initial accuracy for lower cost while retaining identical temperature performance and load drive capability; versus REF3020AIDBZR, it delivers 5× better TC and half the supply current - making MAX6191CESA optimal for battery-powered precision instrumentation.

Availability

MAX6191CESA is available at Aetrix Electronics and suitable for hand-held instruments, analog-to-digital converters, and industrial process control systems requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6191CESA 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX6190–MAX6195/MAX6198 family was designed specifically for micropower, high-accuracy voltage referencing in battery-operated and space-constrained systems - emphasizing low dropout, ultra-low supply current, and robust capacitive-load stability.

FAQ

What is the maximum load current supported by the MAX6191CESA?

The MAX6191CESA supports bidirectional output current up to ±500µA while maintaining specified accuracy and stability. It can source up to +500µA into a load and sink up to -500µA from a load, with guaranteed load regulation of 0.12µV/µA. This eliminates the need for external buffer amplifiers in most precision ADC/DAC reference applications, and the device remains stable with capacitive loads up to 2.2nF.

Does the MAX6191CESA require an external output capacitor?

No, the MAX6191CESA does not require an external output capacitor for stability - it is internally compensated and guaranteed stable with capacitive loads from 0 to 2.2nF. However, adding a small capacitor (e.g., 100pF–1nF) may improve transient response in applications with rapidly changing loads or noisy supplies. The absence of mandatory external capacitance saves PCB area and simplifies layout in compact portable instruments.

What is the dropout voltage specification for the MAX6191CESA?

The MAX6191CESA has a maximum dropout voltage of 100mV at 500µA load current, defined as the minimum VIN − VOUT required to maintain output regulation within 0.2% of nominal 2.048V. This allows reliable operation from supply rails as low as 2.5V - ideal for single-cell lithium or regulated 3V systems. Dropout remains stable across temperature and load, supporting consistent performance in battery-voltage-declining applications.

How does the MAX6191CESA compare to shunt voltage references in terms of power efficiency?

Unlike shunt references that draw constant current through a series resistor, the MAX6191CESA is a series-mode reference drawing only ≤35µA quiescent current - independent of load - and increasing supply current only when sourcing output current. This architecture avoids wasted bias current, improves battery life significantly, and eliminates the need to size the input resistor for worst-case load conditions. Its 0.8µA/V supply current variation further enhances efficiency across wide input voltage ranges.

Is the MAX6191CESA pin-compatible with other members of the MAX6190–MAX6195/MAX6198 family?

Yes, all devices in the MAX6190–MAX6195/MAX6198 family, including MAX6191CESA, share identical 8-pin SO package dimensions, pinout (IN, OUT, GND, N.C.), and footprint. This enables drop-in replacement across output voltages (1.25V to 5.0V) and accuracy grades (A/B/C) without PCB redesign - simplifying inventory management and design flexibility for multi-voltage reference requirements.