Analog Devices Inc./Maxim Integrated MAX6337US20D3

Overview

MAX6337US20D3 from Maxim Integrated is an ultra-low-voltage, open-drain microprocessor supervisory circuit designed to monitor 1.8V–3.3V power supplies and assert a reliable active-low reset signal during brownout, power-up, or manual reset events. It features a factory-trimmed 2.00V reset threshold, 100ms minimum reset timeout, guaranteed operation down to VCC = 1.0V, and consumes only 3.3µA at 2.5V - enabling use in battery-powered instrumentation and automotive control modules.

For engineers reviewing the MAX6337US20D3 datasheet, MAX6337US20D3 pinout, MAX6337US20D3 application, or MAX6337US20D3 equivalent, key selection criteria include its open-drain RESET output for bidirectional µP interface (e.g., Motorola 68HC11), immunity to sub-24µs VCC transients, and compatibility with space-constrained SOT143 layouts requiring no external components.

Technical Context

The MAX6337US20D3 implements a precision bandgap-based reset comparator with ±1.8% (TYP) room-temperature threshold accuracy and ±3% variation over –40°C to +125°C. Its internal 20kΩ MR pull-up resistor enables direct connection of a momentary switch to GND without external debounce circuitry.

Reset assertion is triggered by either VCC falling below 2.00V (with 24µs propagation delay at 10V/ms slew) or a logic-low pulse on MR ≥160µs; reset remains active for ≥100ms after VCC rises above threshold or MR returns high. The open-drain RESET output requires an external pull-up and supports bidirectional reset arbitration in µP systems.

Key Specifications

Pinout & Package

MAX6337US20D3 is housed in a 4-pin SOT143 package (3.0mm × 1.6mm × 1.1mm), optimized for space-constrained PCB layouts and compatible with standard pick-and-place equipment.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microprocessor reset supervision applications.

Compared with MAX6337US20D3, the MAX6336US20D3 offers lower minimum VCC operation (0.7V vs. 1.0V) but lacks open-drain flexibility, while the MAX811TEUS20D3 provides identical threshold/timing but demands external MR conditioning - making MAX6337US20D3 optimal for bidirectional, space-constrained, and low-component-count designs.

Availability

MAX6337US20D3 is available at Aetrix Electronics and suitable for industrial controllers, automotive ECUs, and portable medical instruments requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6337US20D3 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 analog, mixed-signal, and power-management ICs for industrial, automotive, and computing applications.

The MAX6335/MAX6336/MAX6337 family delivers ultra-low-voltage, low-power µP supervisory circuits targeting space- and power-constrained systems where reliability under brownout and transient conditions is critical.

FAQ

What is the factory-trimmed reset threshold voltage for MAX6337US20D3?

The MAX6337US20D3 has a factory-trimmed reset threshold of 2.00V, with ±1.8% typical tolerance at +25°C and ±3% maximum variation across –40°C to +125°C. This value is confirmed in Table 1 of the datasheet and corresponds to the "20" suffix in the part number. The threshold is set during wafer sort and requires no external adjustment.

Does MAX6337US20D3 support manual reset, and how is it implemented?

Yes, MAX6337US20D3 supports manual reset via its MR pin (Pin 3). A logic-low pulse ≥160µs asserts reset; the device includes an internal 20kΩ pull-up resistor, so MR may be left unconnected if unused. Connecting a normally open switch between MR and GND provides fully debounced manual reset without external components - a key feature confirmed in the Applications Information section.

What is the minimum supply voltage at which MAX6337US20D3 guarantees correct reset output behavior?

MAX6337US20D3 guarantees correct RESET/RESET output state down to VCC = 1.0V, as explicitly stated in the General Description and Absolute Maximum Ratings sections. This differs from the MAX6335/MAX6336 variants (guaranteed to 0.7V) due to the open-drain output architecture's reduced sinking capability below 1.0V.

Can MAX6337US20D3 be used with microcontrollers that have bidirectional reset pins?

Yes, MAX6337US20D3 is specifically designed for this use case. Its open-drain active-low RESET output allows direct connection to bidirectional µP reset pins (e.g., Motorola 68HC11), as illustrated in Figure 1 of the datasheet. An external pull-up resistor enables wired-OR reset arbitration, letting either the supervisor or µP assert reset on the shared line.

What is the guaranteed minimum reset timeout period for MAX6337US20D3?

The guaranteed minimum reset timeout period for MAX6337US20D3 is 100ms, corresponding to the "D3" suffix in the part number. This value is specified in the Electrical Characteristics table under "Reset Active Timeout Period (tRP)" and is fully characterized over –40°C to +125°C, ensuring reliable µP initialization across automotive and industrial temperature ranges.