Analog Devices Inc./Maxim Integrated MAX6409BS42+T

Overview

MAX6409BS42+T from Maxim Integrated is an ultra-low-power voltage detector IC designed for battery and power-supply monitoring in portable systems. It features a factory-trimmed 4.20V detection threshold, active-low push-pull output, ±2.5% accuracy over -40°C to +85°C, 500nA supply current, and guaranteed operation down to VCC = 1.0V - enabling reliable reset generation in Li+-based handheld devices.

For engineers reviewing the MAX6409BS42+T datasheet, MAX6409BS42+T pinout, MAX6409BS42+T application, or MAX6409BS42+T equivalent, key selection considerations include its 4.20V trip point, UCSP-4 package footprint, manual reset (MR) input with internal 50kΩ pullup, immunity to sub-100ns VCC transients, and compatibility with 1.0–5.5V supply rails in space-constrained battery-powered designs.

Technical Context

The MAX6409BS42+T implements a precision bandgap reference comparator with hysteresis of 9.5mV and temperature coefficient of 40ppm/°C, ensuring stable threshold behavior across industrial temperature ranges. Its push-pull output drives logic directly without external pullups and remains valid even when VCC drops to 1.0V.

It integrates a manual reset input (MR) with 1µs minimum pulse width support, 100ns glitch rejection, and internal 50kΩ pullup - allowing momentary switch or CMOS/TTL control. The device ignores fast negative-going VCC transients below the maximum duration defined by threshold overdrive, per the transient immunity curve in the datasheet.

Key Specifications

Pinout & Package

MAX6409BS42+T is housed in a 4-bump, 2mm × 2mm chip-scale package (UCSP-4) with bottom-side solder bumps. This ultra-compact footprint occupies ~30% of the area of an SC70-4 package and is optimized for high-density portable PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS3808G33DBVR and APX803S-42SA-7, the MAX6409BS42+T uniquely combines 4.20V precision, 500nA current, MR input, and UCSP-4 size - making it optimal for next-gen compact Li+ devices where all four attributes are required simultaneously.

Availability

MAX6409BS42+T is available at Aetrix Electronics and suitable for smartphone power management, wireless headset battery monitoring, portable medical glucose meters, and industrial handheld scanners requiring stable component supply with long-term lifecycle assurance.

Supply support for MAX6409BS42+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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX6406–MAX6411 family was designed specifically for ultra-low-power voltage monitoring in space-constrained portable electronics, targeting battery-powered devices needing precise, factory-trimmed reset thresholds without external components.

FAQ

What is the exact detection threshold voltage of the MAX6409BS42+T?

The MAX6409BS42+T has a factory-trimmed nominal detection threshold of 4.20V, with tolerance of ±2.5% over the full operating temperature range (-40°C to +85°C). At +25°C, the typical threshold is 4.200V, and the min/max limits are 4.095V and 4.305V respectively, as specified in Table 1 of the datasheet.

Does the MAX6409BS42+T require an external pullup resistor on its OUT pin?

No, the MAX6409BS42+T does not require an external pullup resistor because it features an active-low push-pull output. Unlike open-drain variants (e.g., MAX6411), the MAX6409BS42+T actively drives both logic high and logic low states, enabling direct interface with microcontroller reset inputs without additional components.

Can the MAX6409BS42+T operate reliably below 1.8V supply voltage?

Yes, the MAX6409BS42+T is fully specified to operate down to VCC = 1.2V (minimum) and guarantees correct output logic state down to VCC = 1.0V. This capability allows it to assert reset during deep battery discharge in single-cell Li+ systems, well below typical LDO dropout voltages.

What is the function and electrical behavior of the MR pin on the MAX6409BS42+T?

The MR pin on the MAX6409BS42+T is an active-low manual reset input with an internal 50kΩ pullup to VCC. Pulling MR below 0.8V (VIH threshold) asserts the OUT pin low. It supports minimum pulse widths of 1µs and rejects glitches shorter than 100ns, enabling robust reset initiation via momentary switch or digital logic without external components.

Is the MAX6409BS42+T compatible with lead-free reflow processes?

Yes, the MAX6409BS42+T uses a UCSP-4 package qualified for standard lead-free reflow profiles, including peak temperatures up to +235°C. The bump-reflow specification aligns with JEDEC J-STD-020 requirements, and the device is rated for moisture sensitivity level MSL-1 - meaning it can be assembled without baking prior to reflow.