Analog Devices Inc./Maxim Integrated MAX6700UT

Overview

MAX6700UT from Maxim Integrated is a precision triple-voltage microprocessor supervisory circuit in a 6-pin SOT23 package, monitoring three adjustable supply voltages down to 0.62V with ±1.5% threshold accuracy, 5µs propagation delay, and 35µA supply current-designed for reliable power-on reset and brownout detection in compact embedded systems.

For engineers reviewing the MAX6700UT datasheet, MAX6700UT pinout, MAX6700UT application, or MAX6700UT equivalent, this device serves as a low-power, high-accuracy voltage detector for multi-rail systems where space, supply current, and fast response to overvoltage/undervoltage events are critical selection criteria.

Technical Context

The MAX6700UT uses an internal 0.62V bandgap reference and precision comparators with 0.3% threshold hysteresis to monitor three user-adjustable input voltages (IN1, IN3, IN4), while powered from IN2 (or VCC in Q variant). It features open-drain RESET output with 10µA internal pullup to IN2, valid as long as IN2 ≥ 1V or VCC ≥ 2V.

Unlike the MAX6710 series, the MAX6700UT acts strictly as a voltage detector-not a reset timer-asserting RESET low when any monitored input falls below its threshold and deasserting it after a fixed 5µs propagation delay once all inputs exceed thresholds. Its BiCMOS process ensures guaranteed operation from –40°C to +85°C.

Key Specifications

Pinout & Package

Package: 6-pin SOT23-6, surface-mount, footprint-compatible with industry-standard 6-lead SOT packages.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6701UT and TPS3808G33DBVR, the MAX6700UT uniquely delivers triple adjustable-threshold monitoring in a single 6-pin SOT23, enabling compact, low-power, and highly flexible power supervision without external resistors for reference scaling or timing components.

Availability

MAX6700UT is available at Aetrix Electronics and suitable for industrial PLCs, network routers, medical handhelds, and automotive infotainment systems requiring stable component supply, extended temperature support, and minimal board space.

Supply support for MAX6700UT 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 computing markets.

The MAX6700 series belongs to Maxim's µP supervisory product line, engineered specifically for compact, low-power, multi-rail voltage monitoring in space- and energy-constrained embedded systems.

FAQ

What is the primary function of the MAX6700UT?

The MAX6700UT is a triple-voltage supervisory circuit functioning as a precision voltage detector. It monitors three user-adjustable supply rails using an internal 0.62V reference and asserts an active-low open-drain RESET signal within 5µs when any monitored voltage falls below its threshold. Unlike reset timers such as the MAX6710, the MAX6700UT does not include a built-in timeout period - its output deasserts immediately after the 5µs propagation delay once all inputs recover.

How do I configure the MAX6700UT to monitor a 1.2V rail?

To monitor a 1.2V rail with the MAX6700UT, connect it to one of the adjustable inputs (IN1, IN3, or IN4) through an external resistor divider. Using the formula R1 = R2 × ((V_INTH/0.62V) − 1), select R2 ≤ 100kΩ to maintain <1% error given the ±0.4µA max input current on IN1. For 1.2V, R1 ≈ 0.94 × R2 (e.g., R2 = 100kΩ, R1 = 94kΩ). The MAX6700UT's 0.62V internal threshold ensures accurate scaling across temperature.

Does the MAX6700UT require an external pullup resistor on the RESET pin?

No, the MAX6700UT includes a 10µA internal pullup to IN2, making an external pullup unnecessary in most 3.3V or 5V logic interfaces. However, if interfacing with a different logic supply (e.g., 1.8V), an external pullup to that voltage is required - the internal pullup will not conflict due to reverse-current protection. The MAX6700UT's RESET pin is open-drain and rated for 20mA sink current, supporting direct connection to standard CMOS inputs.

What is the minimum operating voltage for the MAX6700UT's IN2 supply pin?

The MAX6700UT requires IN2 ≥ 1.2V to operate correctly, as specified in the Absolute Maximum Ratings and Electrical Characteristics tables. Crucially, the RESET output remains valid (i.e., correctly asserted or deasserted) as long as IN2 stays ≥ 1V - allowing graceful degradation during brownout conditions. Below 1V, RESET behavior is undefined. This 1.2V minimum ensures reliable comparator and bandgap reference operation across the full –40°C to +85°C range.

Can unused inputs on the MAX6700UT be left floating?

No - unused inputs on the MAX6700UT must not be left floating. Per the Applications Information section, unused adjustable inputs (IN1, IN3, IN4) should be connected via a 1MΩ series resistor to IN2 (or VCC) to limit bias current and prevent false triggering. Floating inputs risk noise coupling and erratic RESET behavior. Grounding unused inputs is also prohibited, as it may violate absolute maximum ratings or cause excessive current draw through internal clamps.