Analog Devices Inc./Maxim Integrated MAX6408BS31

Overview

MAX6408BS31 from Maxim Integrated is an ultra-low-power, open-drain, active-low voltage detector with a factory-trimmed 3.08V threshold (±2.5% over -40°C to +85°C), 500nA supply current, and guaranteed output validity down to VCC = 1.0V. It monitors regulated system or battery voltages in portable electronics, asserting reset when supply drops below threshold while ignoring fast transients.

For engineers reviewing the MAX6408BS31 datasheet, MAX6408BS31 pinout, MAX6408BS31 application, or MAX6408BS31 equivalent, key selection factors include its open-drain output configuration, 3.08V detection point, UCSP-4 package footprint, manual reset input with internal 50kΩ pullup, and immunity to sub-100ns VCC glitches.

Technical Context

The MAX6408BS31 uses a precision bandgap reference comparator architecture with factory laser trimming for stable threshold accuracy. Its open-drain output requires an external pullup and supports interfacing to logic supplies up to 5.5V, enabling flexible voltage domain isolation.

It features a dedicated active-low manual reset (MR) input with glitch rejection (100ns), MR-to-OUT delay of 200ns, and propagation delay of 42µs (VCC falling). The device operates across VCC = 1.2V to 5.5V and remains functional down to 1.0V, ensuring reliable reset assertion during brownout conditions.

Key Specifications

Pinout & Package

MAX6408BS31 is housed in a 4-bump, 2mm × 2mm UCSP (Ultra Compact Silicon Package) - a chip-scale package with bottom-mounted solder bumps. This package delivers 70% area reduction versus SC70 and is optimized for space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6406BS31 and TLV803EB30DBZR, MAX6408BS31 uniquely combines open-drain flexibility, integrated manual reset, and ultra-small UCSP-4 packaging-making it optimal for compact, multi-rail, or serviceable portable designs requiring field-initiated reset capability.

Availability

MAX6408BS31 is available at Aetrix Electronics and suitable for portable/battery-powered equipment, cell phones, and MP3 players requiring stable component supply with long-term lifecycle support and RoHS-compliant sourcing options.

Supply support for MAX6408BS31 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 MAX6406–MAX6411 family was designed specifically for ultra-low-power voltage supervision in space-constrained portable electronics, emphasizing minimal quiescent current, factory-trimmed accuracy, and chip-scale packaging.

FAQ

What is the exact factory-trimmed threshold voltage of MAX6408BS31?

The MAX6408BS31 has a nominal threshold voltage of 3.08V, with a tolerance of ±2.5% over the full operating temperature range (–40°C to +85°C). This value is laser-trimmed at wafer test and confirmed in Table 1 of the datasheet under suffix "31". At +25°C, the typical threshold is 3.08V, with min/max of 3.034V/3.126V.

Does MAX6408BS31 require an external pullup resistor on the OUT pin?

Yes, MAX6408BS31 requires an external pullup resistor on the OUT pin because it features an open-drain output. The pullup can connect to any logic supply up to 5.5V. Typical values range from 10kΩ to 100kΩ depending on bus capacitance and rise-time requirements. No pullup is needed for push-pull variants like MAX6406BS31.

Can MAX6408BS31 operate reliably below 1.2V supply voltage?

MAX6408BS31 guarantees correct output logic state down to VCC = 1.0V, though the absolute maximum ratings specify minimum operating VCC as 1.2V. Below 1.2V, the device remains functional and will assert OUT low if VCC falls below 3.08V-but startup time and propagation delay may increase beyond datasheet limits. For guaranteed parametric performance, maintain VCC ≥ 1.2V.

What is the function and electrical behavior of the MR pin on MAX6408BS31?

The MR pin on MAX6408BS31 is an active-low manual reset input with an internal 50kΩ pullup to VCC. Pulling MR low asserts the OUT pin (drives it low), overriding the voltage-monitoring function. OUT remains asserted as long as MR is held low. When left unconnected or tied to VCC, MR is inactive and the device performs autonomous voltage supervision.

Is MAX6408BS31 available in RoHS-compliant and lead-free versions?

Yes, MAX6408BS31 is available in RoHS-compliant and lead-free versions denoted by the "+" suffix (e.g., MAX6408BS31+T). Non-RoHS versions (e.g., MAX6408BS31-T) are also offered. Both variants use the same UCSP-4 package and share identical electrical specifications; the difference lies solely in material composition and plating.