Analog Devices Inc./Maxim Integrated MAX6370KA

Overview

MAX6370KA from Maxim Integrated is a pin-selectable watchdog timer supervisor IC designed to monitor microprocessor activity in safety-critical embedded systems. It features push-pull active-low watchdog output with 1ms pulse width, operates from +2.5V to +5.5V, draws only 8µA supply current, and uses an 8-pin SOT23 package for space-constrained industrial controllers and automotive ECUs.

For engineers reviewing the MAX6370KA datasheet, MAX6370KA pinout, MAX6370KA application, or MAX6370KA equivalent, this device supports real-time µP supervision with configurable startup delay (1ms–60s) and watchdog timeout (1ms–60s), disable capability via SET pins, and robust noise immunity in electrically noisy environments.

Technical Context

The MAX6370KA implements a precision analog/digital hybrid watchdog timer with BiCMOS process technology and 1500-transistor circuitry. Its internal timing engine responds to rising or falling edges on WDI, clears on valid transitions, and asserts WDO low after timeout - with no external components required.

Startup delay and watchdog timeout are independently set via three logic-controlled pins (SET0/SET1/SET2), enabling runtime reconfiguration without power cycling. The push-pull output drives directly into µP reset or interrupt inputs, eliminating pull-up resistor design overhead and ensuring fast 1ms pulse assertion under all VCC conditions ≥2.7V.

Key Specifications

Pinout & Package

MAX6370KA is housed in an 8-pin SOT23-8 package (top mark AADD), measuring 3.0mm × 1.7mm × 1.3mm, with gull-wing leads suitable for automated PCB assembly and reflow.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar watchdog timer applications.

Compared with MAX6372KA-T and TPS3823-33DBVR, the MAX6370KA offers full independence between startup delay and timeout periods, runtime reconfigurability, and lowest quiescent current - making it optimal for adaptive, low-power, and safety-certified designs requiring precise timing control.

Availability

MAX6370KA is available at Aetrix Electronics and suitable for industrial PLC controllers, automotive body control modules, and medical infusion pump controllers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6370KA 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 demanding industrial, automotive, and communications applications.

The MAX6369–MAX6374 family was engineered specifically for robust µP supervision in harsh environments, emphasizing configurability, ultra-low power, and noise immunity without external components.

FAQ

What is the watchdog output type and pulse width of the MAX6370KA?

The MAX6370KA features a push-pull active-low watchdog output with a minimum pulse width of 1ms. This output drives directly into microprocessor reset or interrupt pins without requiring an external pull-up resistor. The 1ms duration ensures reliable detection by standard µP reset latches while minimizing system disruption. Unlike open-drain variants in the same family, the MAX6370KA's push-pull structure guarantees defined high-impedance release after deassertion, simplifying interface design.

How do the SET0, SET1, and SET2 pins configure timing on the MAX6370KA?

The SET0, SET1, and SET2 pins on the MAX6370KA form a 3-bit code that independently selects both startup delay and watchdog timeout periods from eight discrete options each, ranging from 1ms to 60s. For example, SET2=0, SET1=0, SET0=0 yields 1ms for both parameters, while SET2=1, SET1=1, SET0=1 selects 60s. Setting SET2=0, SET1=1, SET0=1 disables the watchdog entirely. These pins are sampled at power-up and after any change, with a 300µs internal setup time before new timing takes effect.

Does the MAX6370KA require external components for basic operation?

No, the MAX6370KA requires no external components for core watchdog functionality. Its internal oscillator, edge-detection circuitry, and push-pull output eliminate the need for timing capacitors, pull-up resistors, or buffer stages. Only a 0.1µF ceramic bypass capacitor between VCC and GND (placed ≤0.2 inches from the device) is recommended for noise immunity in electrically noisy environments. All timing, enable/disable, and output drive functions are self-contained within the 8-pin SOT23 package.

What is the supply voltage range and quiescent current of the MAX6370KA?

The MAX6370KA operates from +2.5V to +5.5V, supporting both 3.3V and 5V microprocessor systems without level translation. Its typical supply current is 8µA at +3V and +25°C, with a maximum of 20µA across temperature and voltage extremes. This ultra-low quiescent current enables continuous watchdog supervision in battery-backed or energy-harvesting applications, such as remote industrial sensors and portable medical devices, without compromising runtime.

Can the MAX6370KA's timing settings be changed during system operation?

Yes, the MAX6370KA supports runtime reconfiguration of startup delay and watchdog timeout by changing the logic states of SET0, SET1, and SET2 pins while powered. After a change, the device enters a 300µs internal setup period during which WDI transitions are ignored. If WDO is asserted during the change, the current timeout completes before the new timing parameters activate; if WDO is deasserted, the new timing begins immediately after setup. This capability enables adaptive supervision strategies without power cycling or firmware intervention.