Analog Devices Inc./Maxim Integrated MAX409BESA+

Overview

MAX409BESA+ from Maxim Integrated is a dual, rail-to-rail input/output, micropower operational amplifier optimized for single-supply operation at +2.7V to +6.5V. It delivers 1.2µA max supply current per amplifier, 100kHz gain-bandwidth product, and 70dB min CMRR at 1kHz - enabling precision sensing in battery-powered industrial monitoring and portable medical devices.

For engineers reviewing the MAX409BESA+ datasheet, MAX409BESA+ pinout, MAX409BESA+ application, or MAX409BESA+ equivalent, key selection criteria include ultra-low quiescent current, rail-to-rail I/O swing, guaranteed operation over -40°C to +85°C, and SO-8 package compatibility with space-constrained PCB layouts.

Technical Context

The MAX409BESA+ integrates two independent op-amps sharing a common bias structure to maintain consistent 1.2µA max ICC per channel across temperature. Its input stage uses P-channel JFETs for rail-to-rail common-mode range down to VEE and up to VCC–0.1V, while the output stage supports rail-to-rail swing within 10mV of either rail under 10kΩ load.

This device operates without external compensation and achieves stable unity-gain performance with capacitive loads ≤100pF. It is specified for DC precision (0.8mV max input offset voltage) and AC behavior (100kHz GBW, 0.03% THD+N at 1kHz) under single-supply conditions only.

Key Specifications

Pinout & Package

MAX409BESA+ is housed in an 8-pin SO (Small Outline) package (package code S8-2), measuring 4.9mm × 6.0mm × 1.75mm, with standard 1.27mm pitch and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual micropower op-amp applications.

Compared with TLV2462IDR and OPA2333AIDR, the MAX409BESA+ uniquely balances sub-2µA quiescent current with rail-to-rail I/O and industrial temperature range - making it optimal for multi-year battery deployments where precision and power are co-constrained.

Availability

MAX409BESA+ is available at Aetrix Electronics and suitable for portable medical devices, industrial sensor transmitters, smart environmental monitors, and low-power data loggers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX409BESA+ 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 industrial, medical, communications, and consumer applications.

The MAX406/MAX407/MAX409 family targets ultra-low-power signal conditioning in single-supply systems where battery longevity and rail-to-rail dynamic range are primary design constraints.

FAQ

What is the maximum supply voltage for MAX409BESA+?

The MAX409BESA+ operates with a maximum supply voltage of +6.5V. Exceeding this voltage risks permanent damage to the internal ESD protection structures and input transistors. The device is specified for reliable operation between +2.7V and +6.5V, and all electrical parameters in the datasheet are guaranteed only within this range. For designs using 9V batteries or higher rails, a low-dropout regulator must be used upstream of the MAX409BESA+.

Does MAX409BESA+ support rail-to-rail output swing with heavy loads?

The MAX409BESA+ delivers rail-to-rail output swing only under light loads (≥10kΩ). With 2kΩ loads, output swing degrades to within ~100mV of each rail. This limitation arises from its micropower output stage design, which trades drive strength for ultra-low quiescent current. For applications requiring both rail-to-rail swing and >1mA output current, consider adding an external buffer stage or selecting a higher-IQ op-amp such as the MAX4475.

Is MAX409BESA+ pin-compatible with other devices in the MAX406–MAX419 family?

Yes, MAX409BESA+ shares the same 8-pin SO package and pinout as all dual variants in the MAX406–MAX419 family (e.g., MAX407ESA+, MAX417ESA+). This allows direct substitution in existing layouts when upgrading or downgrading performance parameters such as offset voltage, bandwidth, or temperature grade - provided the replacement part's electrical specifications meet the design requirements.

Can MAX409BESA+ be used with dual supplies?

No, MAX409BESA+ is explicitly designed and characterized for single-supply operation only. Its input common-mode range extends to VEE (GND), and its output cannot swing below VEE. Applying dual supplies (e.g., ±2.5V) violates the absolute maximum ratings and may cause latch-up or parametric failure. For dual-supply applications, select a true dual-supply op-amp such as the MAX44268 or ADA4522-2.

What is the typical input bias current of MAX409BESA+ at 25°C?

The typical input bias current of MAX409BESA+ is 1pA at +25°C, with a maximum of 10pA over the full -40°C to +85°C operating range. This ultra-low value results from its P-channel JFET input stage and makes the MAX409BESA+ suitable for interfacing with high-impedance sensors such as pH electrodes, photodiodes in photovoltaic mode, and piezoelectric elements where leakage-induced errors must be minimized.