Analog Devices Inc./Maxim Integrated MAX6511UT115

Overview

The MAX6511UT115 from Maxim Integrated is a fully integrated remote temperature switch using an external P-N junction (e.g., diode-connected transistor) to monitor remote die or board temperature. It features a factory-programmed +115°C trip threshold, ±5°C accuracy over –40°C to +85°C ambient, 5°C/10°C pin-selectable hysteresis, active-low CMOS output, and operates from +3.0V to +5.5V. It is used for CPU thermal shutdown in high-speed computing systems.

For engineers reviewing the MAX6511UT115 datasheet, MAX6511UT115 pinout, MAX6511UT115 application, or MAX6511UT115 equivalent, key selection considerations include remote-sensing junction interface, hysteresis configuration, supply voltage range, output drive capability, and SOT23-6 package compatibility with space-constrained thermal monitoring designs.

Technical Context

The MAX6511UT115 implements a precision bandgap reference, chopper-stabilized amplifier, and current-steering circuitry to measure forward voltage across an external diode-connected transistor and compute temperature. Its architecture rejects series parasitic resistance up to 100Ω with <1°C error.

It asserts an active-low CMOS output when remote temperature exceeds +115°C and deasserts only after temperature falls below (trip point – hysteresis), selectable as either 5°C or 10°C via the HYST pin. Response time is under 120ms with 2200pF noise-filtering capacitor on DXP/DXN.

Key Specifications

Pinout & Package

MAX6511UT115 is housed in a 6-pin SOT23-6 package (drawing code 21-0058I), footprint-compatible with industry-standard SOT-23 layouts and suitable for reflow assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6512UT115 and MAX6513UT115, the MAX6511UT115 provides direct active-low CMOS drive with no external components needed for µP reset assertion, simplifying layout and reducing BOM count in reset-critical applications.

Availability

MAX6511UT115 is available at Aetrix Electronics and suitable for CPU thermal shutdown, battery pack protection, multichip module monitoring, and fan speed control requiring stable component supply and long-term industrial availability.

Supply support for MAX6511UT115 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 precision analog, mixed-signal, and power management ICs for industrial, computing, and communications markets.

The MAX6511UT115 belongs to Maxim's remote temperature switch product line, designed specifically for accurate, low-cost, hardware-based thermal monitoring using external P-N junctions in space- and power-constrained systems.

FAQ

What is the factory-set temperature trip point for the MAX6511UT115?

The MAX6511UT115 has a factory-programmed temperature trip threshold of +115°C. This value is laser-trimmed during wafer testing and is fixed for the device - no external configuration or calibration is required. The trip point remains stable across its operating ambient temperature range of –40°C to +85°C, with ±5°C accuracy specified over that full range. This makes the MAX6511UT115 suitable for deterministic thermal shutdown in high-reliability applications where consistent behavior is critical.

How does the HYST pin affect the MAX6511UT115's operation?

The HYST pin on the MAX6511UT115 selects hysteresis magnitude: tying it to VDD configures 10°C hysteresis, while tying it to GND selects 5°C. Hysteresis prevents output chatter near the +115°C trip point by requiring temperature to fall below (115°C – hysteresis) before deasserting TOVER. For example, with 10°C hysteresis, TOVER goes low at 115°C and returns high only when temperature drops to 105°C. The pin must be actively driven - floating is not allowed - and uses standard CMOS logic levels.

Can the MAX6511UT115 measure temperature using an internal sensor?

No, the MAX6511UT115 does not include an internal temperature sensor. It is exclusively a remote temperature switch that requires an external P-N junction - typically a diode-connected transistor such as MMBT3904 or SST3904 - connected between DXP (anode) and DXN (cathode, tied to GND). The device measures the forward voltage drop across this external junction to compute temperature. No on-die sensing capability exists; all thermal measurement depends entirely on the external component and its placement relative to the target heat source.

What is the recommended noise-filtering capacitor for the MAX6511UT115's DXP/DXN inputs?

A 2200pF ceramic capacitor is recommended across the DXP and DXN pins of the MAX6511UT115 to filter high-frequency noise and maintain temperature threshold accuracy. This capacitor must be placed physically close to the pins, and deviations of ±50% from 2200pF can introduce up to ±1°C measurement error. Larger values degrade response time and may cause instability; smaller values reduce noise immunity. The capacitor forms part of the sensing network and is required for production-grade accuracy - omitting it compromises the ±5°C specification.

Is the MAX6511UT115 RoHS-compliant and lead-free?

The MAX6511UT115 is not RoHS-compliant or lead-free in its standard SOT23-6 packaging (pkg code U6F-6*), as confirmed by Maxim's official ordering information and materials analysis data. RoHS/lead-free variants exist for other members of the MAX651x family (e.g., MAX6513TTxxx+), but no lead-free version of MAX6511UT115 is listed in the manufacturer's documentation or distributor databases. Customers requiring RoHS compliance should evaluate MAX6513UT115 (SOT23-6, RoHS-qualified per datasheet) or contact Aetrix Electronics for verified alternatives.