Analog Devices Inc./Maxim Integrated MAX6400BS23-T

Overview

MAX6400BS23-T from Maxim Integrated is an ultra-low-power microprocessor supervisory circuit designed to monitor VCC supply voltage and assert a reset signal during brownout or power-up conditions. It features a factory-trimmed 2.320V reset threshold (±2.5% over –40°C to +85°C), active-low push-pull RESET output, 100ms minimum reset timeout, and 500nA typical supply current at 3.0V. It is used in battery-powered portable devices requiring reliable, low-quiescent-power voltage monitoring.

For engineers reviewing the MAX6400BS23-T datasheet, MAX6400BS23-T pinout, MAX6400BS23-T application, or MAX6400BS23-T equivalent, key selection criteria include its 2.32V trip point, UCSP-4 package compatibility, guaranteed reset validity down to VCC = 1.0V, immunity to short VCC transients, and manual reset (MR) input with internal 50kΩ pullup.

Technical Context

The MAX6400BS23-T implements a precision bandgap reference comparator with factory-trimmed threshold accuracy of ±2.5% across –40°C to +85°C and 1.5% at +25°C. Its internal timer ensures a minimum 100ms reset assertion after VCC rises above VTH, with hysteresis of 6.3mV to prevent chatter near threshold.

It supports dual reset initiation: automatic detection of VCC falling below 2.320V and manual assertion via MR pin (active-low, 1µs minimum pulse width, 100ns glitch rejection). The push-pull RESET output drives low with ≤0.4V VOL at 100µA sink and remains valid down to VCC = 1.0V.

Key Specifications

Pinout & Package

MAX6400BS23-T is housed in a 4-bump, 2mm × 2mm chip-scale package (UCSP-4), optimized for space-constrained portable designs. The package uses solder bumps instead of leads and requires careful PCB layout per Maxim's UCSP reliability guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor supervisory applications.

Compared with MAX6400BS23-T, TPS3123QDBVRQ1 offers automotive qualification but consumes 3.6× more current and occupies 3× more board area; STM6313ZWDJ6F provides identical threshold but omits MR and doubles reset timeout-making MAX6400BS23-T optimal for space- and battery-limited portable designs requiring manual reset capability.

Availability

MAX6400BS23-T is available at Aetrix Electronics and suitable for portable medical sensors, wearable fitness trackers, smart remote controls, Bluetooth audio beacons, and other battery-powered equipment requiring stable component supply and long-term lifecycle support.

Supply support for MAX6400BS23-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 semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX6400–MAX6405 family was designed specifically for ultra-low-power voltage supervision in space-constrained portable electronics, emphasizing minimal ICC, factory-trimmed thresholds, and chip-scale packaging.

FAQ

What is the exact reset threshold voltage of the MAX6400BS23-T?

The MAX6400BS23-T has a nominal reset threshold voltage of 2.320V at +25°C, with a tolerance of ±2.5% over the full operating temperature range of –40°C to +85°C. This value is factory-trimmed and specified in Table 1 of the datasheet; the "23" suffix explicitly denotes the 2.320V variant within the MAX6400BS series.

Does the MAX6400BS23-T require an external pullup resistor on the RESET pin?

No, the MAX6400BS23-T does not require an external pullup resistor because it features an active-low push-pull RESET output. Unlike open-drain variants (e.g., MAX6402BS23-T), the MAX6400BS23-T drives both high and low states internally - ensuring clean, fast transitions without external components.

What is the minimum VCC voltage at which the MAX6400BS23-T guarantees correct RESET output behavior?

The MAX6400BS23-T guarantees correct RESET output logic state down to VCC = 1.0V. This means that even when the supply voltage drops to 1.0V, the device will still assert a valid logic-low RESET signal - a critical feature for ensuring reliable shutdown sequencing in deeply brownout conditions.

Can the MAX6400BS23-T be used with microcontrollers that have bidirectional reset pins?

The MAX6400BS23-T is not recommended for direct interfacing with bidirectional reset pins because its push-pull output actively drives both logic states. For such µPs, an open-drain supervisor like MAX6402BS23-T is preferred - it allows shared reset lines with external pullup, enabling either device to assert reset without contention.

What package type and dimensions does the MAX6400BS23-T use?

The MAX6400BS23-T uses a 4-bump ultra-thin chip-scale package (UCSP-4), measuring 2.0mm × 2.0mm with a 0.5mm bump pitch. It is marked "AAB" on top and requires adherence to Maxim's UCSP assembly guidelines - including controlled reflow profiles and PCB pad design - to ensure long-term solder joint reliability.