Analog Devices Inc./Maxim Integrated MAX6337US20D3+T

Overview

MAX6337US20D3+T from Maxim Integrated is an ultra-low-voltage, open-drain microprocessor supervisory circuit designed for 1.8V–3.3V digital systems. It monitors VCC and asserts an active-low RESET signal when supply voltage falls below 2.00V (±2% at +25°C) or when manual reset is triggered, with a guaranteed 100ms minimum timeout period and valid operation down to VCC = 1.0V. Used in portable equipment and automotive controllers for reliable power-on/brownout reset generation.

For engineers reviewing the MAX6337US20D3+T datasheet, MAX6337US20D3+T pinout, MAX6337US20D3+T application, or MAX6337US20D3+T equivalent, key selection criteria include its 2.0V factory-trimmed reset threshold, 100ms reset timeout, open-drain output structure, -40°C to +125°C operating range, and SOT143 package compatibility with legacy supervisors like MAX811/MAX6314.

Technical Context

The MAX6337US20D3+T implements a precision bandgap-based reset comparator with factory-trimmed 2.00V threshold (±1.8% at +25°C, ±3% over full temperature range), immune to fast VCC transients up to 24µs at 10mV overdrive. Its internal debounced manual-reset input (MR) features a 20kΩ pull-up resistor and requires only a 160µs minimum pulse width at VCC = 2.6V.

Reset assertion remains active for ≥100ms after VCC rises above 2.00V or MR is released, ensuring stable µP initialization. The open-drain RESET output supports bidirectional µP interfaces (e.g., Motorola 68HC11) and requires an external pull-up resistor; it guarantees VOL ≤ 0.4V at ISINK = 50µA and VCC ≥ 1.0V.

Key Specifications

Pinout & Package

MAX6337US20D3+T is housed in a 4-pin SOT143 package (JEDEC TO-253-4), measuring 2.9mm × 1.6mm × 1.1mm, with gull-wing leads and lead-free finish (+T suffix). Pin 1 = VCC, Pin 2 = RESET (open-drain), Pin 3 = MR (manual reset input), Pin 4 = GND.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6337US20D3+T, MAX6314US20D3+T offers lower minimum VCC operation but lacks open-drain flexibility, while TLV803EB20DBZR trades temperature range and quiescent current for TI's production scalability-making MAX6337US20D3+T optimal for automotive-grade open-drain reset buses.

Availability

MAX6337US20D3+T is available at Aetrix Electronics and suitable for portable electronics, automotive control units, and industrial PLCs requiring stable component supply with guaranteed long-term availability and lead-free compliance.

Supply support for MAX6337US20D3+T 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 high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and computing markets.

The MAX633x family was designed specifically for ultra-low-voltage microprocessor supervision in battery-critical and thermally harsh environments, emphasizing precision threshold accuracy, minimal quiescent current, and robust transient immunity.

FAQ

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

The MAX6337US20D3+T has a factory-trimmed reset threshold of 2.00V, with ±1.8% tolerance at +25°C and ±3% over the full -40°C to +125°C operating range. This value is laser-trimmed during production and documented in Table 1 of the MAX6335/MAX6336/MAX6337 datasheet. The threshold applies specifically to the US20D3+T variant and is confirmed by the top-mark code KABR on the SOT143 package.

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

Yes, MAX6337US20D3+T includes a debounced manual-reset input (MR) on Pin 3. It features an internal 20kΩ pull-up resistor, so MR can be left unconnected if unused. To trigger reset, assert a logic-low pulse ≥160µs (at VCC = 2.6V) by connecting MR to GND via a momentary switch. No external RC network is required due to on-chip filtering, and MR remains immune to glitches <12ns.

What is the guaranteed minimum reset timeout period for MAX6337US20D3+T, and how is it determined?

The MAX6337US20D3+T guarantees a minimum reset timeout period of 100ms after VCC rises above the 2.00V threshold or after MR is deasserted. This value is factory-programmed and fixed for the D3 suffix. Electrical characterization confirms tRP = 100ms (min), 150ms (typ), and 200ms (max) across temperature, ensuring µP core and peripherals fully stabilize before release.

Can MAX6337US20D3+T operate reliably at VCC = 1.0V, and what are the implications for RESET output validity?

Yes, MAX6337US20D3+T is guaranteed to maintain correct RESET/RESET state down to VCC = 1.0V - unlike the MAX6335/MAX6336 variants (guaranteed to 0.7V). At VCC = 1.0V, the open-drain RESET output still sinks ≥50µA with VOL ≤ 0.4V, ensuring compatible logic-level assertion. However, below 1.0V, sinking capability degrades and RESET may float; thus, system design must ensure VCC does not fall further during critical reset hold time.

Is MAX6337US20D3+T pin-compatible with older Maxim supervisors like MAX811 or MAX6314?

Yes, MAX6337US20D3+T is pin-compatible with MAX811/MAX812 and MAX6314/MAX6315 in the 4-pin SOT143 package. Pin 1 = VCC, Pin 2 = RESET, Pin 3 = MR, Pin 4 = GND across all devices. However, output structure differs: MAX6337US20D3+T uses open-drain, while MAX6314 is push/pull. Direct replacement requires verifying external pull-up presence and µP reset pin compatibility.