Analog Devices Inc./Maxim Integrated MAX6403BS44-T

Overview

MAX6403BS44-T from Maxim Integrated is an ultra-low-power microprocessor supervisory circuit in a 4-bump UCSP package, designed to monitor 4.38V system supply voltage and assert an active-low push-pull reset signal during brownout or power-up conditions. It features ±2.5% threshold accuracy over –40°C to +85°C, 100ms minimum reset timeout, 500nA typical supply current at 3V, and guaranteed reset validity down to VCC = 1.0V. It is used in battery-powered portable electronics requiring reliable, low-quiescent-power supply monitoring.

For engineers reviewing the MAX6403BS44-T datasheet, MAX6403BS44-T pinout, MAX6403BS44-T application, or MAX6403BS44-T equivalent, this page provides verified technical context, pin-level design meaning, real-world use scenarios, and validated alternative options for voltage supervisor selection in space-constrained, low-power embedded systems.

Technical Context

The MAX6403BS44-T implements a precision bandgap reference comparator with factory-trimmed 4.38V reset threshold (±2.5% over temperature), hysteresis of 9.5mV, and 40ppm/°C tempco. Its internal timer ensures reset remains asserted for ≥100ms after VCC rises above threshold, ignoring transients <100ns.

It supports manual reset via MR input with internal 50kΩ pullup, 1µs minimum pulse width, and 100ns glitch rejection. The push-pull RESET output drives low with ≤0.4V VOL at 1.6mA sink and high with ≥0.8×VCC VOH at 800µA source, operating across VCC = 1.2V to 5.5V.

Key Specifications

Pinout & Package

MAX6403BS44-T uses a 4-bump UCSP (2×2 mm) chip-scale package with bottom-soldered bumps. This ultra-compact, leadless construction reduces board area by 70% versus SC70 and suits high-density portable PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6403BS44-T, TPS3808G33DBVR offers lower cost but consumes 3.6× more current and lacks guaranteed 1V operation; ADM6315-43ARTZ-R7 provides better accuracy but omits MR and increases power draw - MAX6403BS44-T uniquely balances ultra-low ICC, 4.38V precision, MR support, and sub-1mm² UCSP size.

Availability

MAX6403BS44-T is available at Aetrix Electronics and suitable for portable medical sensors, industrial handheld terminals, wireless IoT edge nodes, automotive cabin control modules, and battery-backed memory systems requiring stable component supply and long-term lifecycle support.

Supply support for MAX6403BS44-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 MAX6400–MAX6405 family was engineered specifically for ultra-low-power, space-constrained battery-operated systems requiring accurate, self-contained voltage supervision without external components.

FAQ

What is the exact reset threshold voltage of the MAX6403BS44-T?

The MAX6403BS44-T has a factory-trimmed nominal reset threshold of 4.38V, with guaranteed tolerance of ±2.5% over the full operating temperature range of –40°C to +85°C. At +25°C, the typical threshold is 4.38V, with min/max values of 4.270V and 4.489V respectively, as confirmed in Table 1 of the official datasheet.

Does the MAX6403BS44-T require an external pullup resistor on its RESET pin?

No, the MAX6403BS44-T does not require an external pullup resistor because it features an active-low push-pull RESET output. Unlike open-drain supervisors, this device actively drives both logic high and logic low states, enabling direct connection to microprocessor reset inputs without additional components.

Can the MAX6403BS44-T operate reliably at VCC = 1.2V?

Yes, the MAX6403BS44-T is fully specified to operate down to VCC = 1.2V across –40°C to +85°C, and its reset function remains valid even at VCC = 1.0V. This ensures robust brownout detection during deep battery discharge or low-voltage startup sequences in the MAX6403BS44-T application.

What is the function of the MR pin on the MAX6403BS44-T?

The MR (Manual Reset) pin on the MAX6403BS44-T is an active-low input with an internal 50kΩ pullup to VCC. Driving MR low initiates a reset pulse lasting the full 100ms timeout period, even after MR returns high. This allows hardware-based reset triggering via momentary switch or external logic, and the MAX6403BS44-T requires no external biasing for MR operation.

Is the MAX6403BS44-T compatible with standard reflow soldering processes?

Yes, the MAX6403BS44-T's UCSP-4 package is qualified for standard Pb-free reflow soldering with a peak bump reflow temperature of +235°C. However, Maxim cautions that UCSP reliability depends critically on PCB material, assembly process, and thermal profile - users must follow Maxim's UCSP application note guidelines to ensure long-term solder joint integrity for the MAX6403BS44-T.