Analog Devices Inc./Maxim Integrated MAX6509HAZK

Overview

MAX6509HAZK from Maxim Integrated is a resistor-programmable SOT23-5 temperature switch with open-drain output, ±0.5°C typical threshold accuracy, 2°C or 10°C pin-selectable hysteresis, and -40°C to +125°C operating range. It interfaces directly with microprocessor reset inputs for thermal monitoring in high-speed computing systems.

For engineers reviewing the MAX6509HAZK datasheet, MAX6509HAZK pinout, MAX6509HAZK application, or MAX6509HAZK equivalent, this page delivers verified technical context, validated pin functions, confirmed thermal trip behavior, and real-world design implications for µP reset, fan control, and overtemperature alarm circuits.

Technical Context

The MAX6509HAZK integrates dual temperature-dependent references (one positive, one negative TC) and a comparator to determine trip point. Its SET pin accepts a 1% external resistor to program thresholds across -40°C to +125°C using documented polynomial equations.

Hysteresis is selected via HYST pin (GND = 2°C, VCC = 10°C); unconnected HYST is prohibited. The open-drain OUT sinks current only and requires an external pull-up for logic-high assertion - no internal pull-up is present, distinguishing it from the MAX6510.

Key Specifications

Pinout & Package

SOT23-5 package: 2.9mm × 1.6mm × 1.1mm body, gull-wing leads, RoHS-compliant, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6509HAUK+T, MAX6509HAZK offers identical performance and pinout but differs in packaging format; versus LM75BIMM/NOPB, MAX6509HAZK provides analog simplicity, programmability, and direct hardware reset capability without MCU dependency.

Availability

MAX6509HAZK is available at Aetrix Electronics and suitable for microprocessor thermal reset, fan speed control, and overtemperature alarm systems requiring stable component supply, long-term lifecycle support, and guaranteed RoHS compliance.

Supply support for MAX6509HAZK 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, mixed-signal, and power management ICs for industrial, automotive, and computing applications.

The MAX6509 belongs to Maxim's resistor-programmable temperature switch product line, engineered for cost-sensitive, high-reliability thermal protection where programmability, low power, and hardware autonomy are essential.

FAQ

What is the function of the HYST pin on the MAX6509HAZK?

The HYST pin on the MAX6509HAZK selects hysteresis magnitude: connecting HYST to GND configures 2°C hysteresis, while tying it to VCC selects 10°C. This prevents output chatter near the trip point. Leaving HYST floating is prohibited - it increases supply current and risks undefined behavior. The MAX6509HAZK uses this pin exclusively for hysteresis control and does not support any other function.

Does the MAX6509HAZK include an internal pull-up resistor on its output?

No, the MAX6509HAZK has a true open-drain output with no internal pull-up resistor. An external pull-up resistor must be connected between VCC and the OUT pin to establish a logic-high state when the output is not asserted. This differs from the MAX6510, which offers internal pull-up in one of its three selectable output modes. The MAX6509HAZK's external pull-up requirement enables flexible voltage translation and wired-OR configurations.

How is the temperature threshold set for the MAX6509HAZK?

The temperature threshold of the MAX6509HAZK is set by connecting a 1% tolerance resistor between the SET pin and GND. Resistance value is calculated using published equations: for -40°C to 0°C, R_SET(kΩ) = [(1.3258 × 10⁵)/(T+1.3)] − 310.1693 − [(5.7797 × 10⁶)/(T+1.3)²]; for 0°C to +125°C, R_SET(kΩ) = [(8.3793 × 10⁴)/T] − 211.3569 + [(1.2989 × 10⁵)/T²], where T is Kelvin. The MAX6509HAZK's H-suffix confirms set-hot operation.

What does the "H" suffix in MAX6509HAZK indicate?

The "H" suffix in MAX6509HAZK denotes set-hot functionality: the device asserts its output when temperature rises above the programmed threshold and deasserts only after temperature falls below threshold minus hysteresis. This ensures correct behavior for overtemperature shutdown. The alternative "C" suffix (e.g., MAX6509CAZK) indicates set-cold operation - assertion on falling temperature. The MAX6509HAZK is specifically designed for hot-trip applications such as CPU thermal protection.

Can the MAX6509HAZK be used to create a temperature window detector?

Yes, the MAX6509HAZK can be used in a temperature window detector when paired with a set-cold device (e.g., MAX6509CAZK). Their open-drain outputs can be wire-ORed using a single external pull-up resistor. When either device asserts, the combined output signals out-of-range condition. This configuration requires no additional logic or microcontroller - the MAX6509HAZK contributes the upper-bound trip point, enabling simple, reliable thermal window monitoring in space-constrained designs.