Analog Devices Inc./Maxim Integrated MAX6405BS46

Overview

MAX6405BS46 from Maxim Integrated is an ultra-low-power microprocessor supervisory circuit with open-drain active-low reset output, factory-trimmed 4.63V threshold (±2.5% over -40°C to +85°C), 100ms minimum reset timeout, and 500nA typical supply current at 3.0V. It monitors VCC in battery-powered systems and asserts RESET when voltage falls below threshold, supporting reliable power-up/brownout detection in portable electronics.

For engineers reviewing the MAX6405BS46 datasheet, MAX6405BS46 pinout, MAX6405BS46 application, or MAX6405BS46 equivalent, key selection criteria include its 4.63V reset threshold accuracy, UCSP-4 package footprint, manual reset input with internal 50kΩ pullup, guaranteed reset validity down to VCC = 1.0V, and immunity to sub-200ns VCC transients.

Technical Context

The MAX6405BS46 uses a precision bandgap reference comparator to monitor VCC against its factory-set 4.63V threshold, with ±2.5% accuracy across -40°C to +85°C and 40ppm/°C tempco. Its internal timer ensures a minimum 100ms reset timeout after VCC rises above threshold.

It features an open-drain RESET output requiring external pullup, a manual reset (MR) input with 1µs minimum pulse width and 100ns glitch rejection, and operates from 1.2V to 5.5V supply while maintaining valid reset logic down to VCC = 1.0V.

Key Specifications

Pinout & Package

MAX6405BS46 is housed in a 4-bump UCSP (Ultra-Compact Silicon Package) measuring 2mm × 2mm, with solder bumps replacing leads for minimal PCB footprint and thermal performance suitable for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6403BS46, MAX6405BS46 offers open-drain flexibility for shared reset buses; compared with TPS3808G33, it delivers 3x lower quiescent current and 70% smaller footprint but fixed 100ms timeout - critical for space- and battery-limited portable designs.

Availability

MAX6405BS46 is available at Aetrix Electronics and suitable for cell phones, MP3 players, and pagers requiring stable component supply, long-term lifecycle support, and consistent UCSP-4 packaging for high-volume portable manufacturing.

Supply support for MAX6405BS46 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 and mixed-signal ICs for power, sensing, and interface applications, with emphasis on high-reliability, low-power solutions for portable and industrial markets.

The MAX6400–MAX6405 family was engineered specifically for ultra-low-power microprocessor supervision in battery-critical portable equipment, delivering factory-trimmed thresholds and chip-scale packaging without external components.

FAQ

What is the exact reset threshold voltage of the MAX6405BS46 and how accurate is it over temperature?

The MAX6405BS46 has a nominal reset threshold of 4.63V, with ±2.5% accuracy guaranteed over the full operating temperature range of -40°C to +85°C. At +25°C, the threshold is specified as 4.560V (min) to 4.699V (max), and the tempco is 40ppm/°C - meaning drift is tightly controlled for stable brownout detection in 5V systems.

Does the MAX6405BS46 require an external pullup resistor on the RESET pin?

Yes, the MAX6405BS46 features an open-drain RESET output, so an external pullup resistor is mandatory to establish a defined high state when reset is inactive. Typical values range from 10kΩ to 100kΩ depending on bus capacitance and rise-time requirements; the device itself does not provide internal pullup on RESET.

Can the MAX6405BS46 operate reliably at VCC voltages below 2.0V?

Yes, the MAX6405BS46 guarantees correct reset logic state down to VCC = 1.0V, and its electrical specifications are validated from 1.2V to 5.5V. This allows robust operation during deep brownout conditions where other supervisors may fail, making it suitable for Li-ion battery discharge monitoring down to ~2.8V and beyond.

What is the function and electrical behavior of the MR pin on the MAX6405BS46?

The MR pin on the MAX6405BS46 is an active-low manual reset input with an internal 50kΩ pullup to VCC. Driving MR low asserts RESET immediately, and reset remains active for the full 100ms timeout period after MR returns high. It accepts TTL/CMOS logic levels and rejects glitches shorter than 100ns, enabling reliable pushbutton or logic-controlled reset initiation.

Is the MAX6405BS46 pin-compatible with other members of the MAX6400–MAX6405 family?

Yes, all MAX6400–MAX6405 variants, including MAX6405BS46, share identical UCSP-4 pinout (GND, RESET, MR, VCC) and footprint. However, output type differs: MAX6405BS46 uses open-drain active-low RESET, whereas MAX6403BS46 uses push-pull active-low - requiring circuit review before substitution due to pullup dependency.