Analog Devices Inc./Maxim Integrated MAX6512UT085

Overview

The MAX6512UT085 from Maxim Integrated is a remote temperature switch IC that uses an external P-N junction (e.g., diode-connected transistor) to monitor remote die or board temperature, asserting an active-low open-drain output when temperature exceeds +85°C - with ±3°C accuracy over -5°C to +55°C ambient and ±5°C over -40°C to +85°C. It operates from +3.0V to +5.5V, consumes 400µA typical supply current, and features pin-selectable 5°C or 10°C hysteresis. It is commonly used for microprocessor reset or interrupt signaling in CPU thermal monitoring.

For engineers reviewing the MAX6512UT085 datasheet, MAX6512UT085 pinout, MAX6512UT085 application, or MAX6512UT085 equivalent, key selection considerations include its open-drain output topology, +85°C factory-trip threshold, SOT23-6 package, hysteresis configuration via HYST pin, and compatibility with standard remote diode sensors such as MMBT3904.

Technical Context

The MAX6512UT085 integrates a precision bandgap reference, chopper-stabilized amplifier, current source, and comparator to measure forward voltage across an external P-N junction and compute temperature. Its architecture rejects series parasitic resistance up to 100Ω with <1°C error and employs oversampling and internal filtering for noise immunity.

It implements a fixed +85°C trip point with hysteresis selected by logic level on the HYST pin (GND = 5°C, VDD = 10°C), and asserts TOVER low upon overtemperature detection. The open-drain output requires an external pull-up and is rated for 1mA sink current at VOL ≤ 0.2V.

Key Specifications

Pinout & Package

MAX6512UT085 is housed in a 6-pin SOT23-6 package (JEDEC MO-178AA, drawing 21-0058I), with 1.9mm × 2.9mm footprint and 1.1mm max height. Thermal pad is not present; standard reflow profile applies.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar remote temperature switch applications.

Compared with MAX6512UT085, MAX6511UT085 offers simpler drive but lacks bus-sharing capability, while LM75BIMM-85/NOPB adds configurability and diagnostics at the cost of firmware dependency and slower response.

Availability

MAX6512UT085 is available at Aetrix Electronics and suitable for CPU thermal shutdown, battery pack safety monitoring, and power supply thermal protection requiring stable component supply across industrial, computing, and automotive-qualified designs.

Supply support for MAX6512UT085 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 U.S.-based semiconductor company specializing in precision analog, mixed-signal, and power management ICs for industrial, computing, and communications markets.

The MAX651x family was designed specifically for low-cost, high-reliability remote temperature monitoring in space-constrained applications - emphasizing simplicity, accuracy, and robustness against PCB parasitics and EMI.

FAQ

What is the exact temperature trip point of the MAX6512UT085?

The MAX6512UT085 has a factory-programmed temperature threshold of +85°C. This value is laser-trimmed during production and specified with ±3°C accuracy over -5°C to +55°C ambient temperature, and ±5°C over -40°C to +85°C ambient. The trip point is fixed and not user-adjustable.

Does the MAX6512UT085 require an external pull-up resistor on the TOVER pin?

Yes, the MAX6512UT085 features an active-low open-drain TOVER output, which can only sink current. An external pull-up resistor (typically 4.7kΩ to VDD) is required to establish a valid high logic level when the output is deasserted. Without it, TOVER remains floating and cannot drive downstream logic reliably.

Which external diode-connected transistors are recommended for use with the MAX6512UT085?

Maxim recommends diode-connected transistors including MMBT3904 (ON Semiconductor), CMPT3904 (Central Semiconductor), SST3904 (Rohm), and KST3904-TF (Samsung). These devices exhibit tight V_BE consistency and low forward current gain variation - critical for achieving the specified ±3°C accuracy with the MAX6512UT085.

How does hysteresis work on the MAX6512UT085, and how is it configured?

Hysteresis on the MAX6512UT085 is configured via the HYST pin: connect to GND for 5°C hysteresis or to VDD for 10°C. When temperature rises past +85°C, TOVER goes low; it remains low until temperature falls to (+85°C − hysteresis), preventing output chatter near the trip point. The HYST pin must never be left floating.

Can the MAX6512UT085 measure temperature accurately with long PCB traces to the remote diode?

Yes - the MAX6512UT085 is designed to tolerate up to 100Ω of series resistance in the DXP/DXN paths with less than 1°C trip-point error. To maintain accuracy, route DXP and DXN as a tightly coupled pair, surround them with ground plane, and place the 2200pF noise-filtering capacitor close to the IC pins.