Analog Devices Inc./Maxim Integrated MAX6803US44D3

Overview

MAX6803US44D3 from Maxim Integrated is a push/pull, active-high microprocessor supervisory circuit in 4-pin SOT143 packaging, designed for precise power-supply monitoring at V_CC = 4.38V threshold with 100ms minimum reset timeout, ultra-low 4µA supply current, and guaranteed operation down to 0.7V V_CC. It asserts RESET high during brownout or manual reset, supporting critical µP power sequencing in portable and industrial control systems.

For engineers reviewing the MAX6803US44D3 datasheet, MAX6803US44D3 pinout, MAX6803US44D3 application, or MAX6803US44D3 equivalent, key selection considerations include its factory-trimmed 4.38V reset threshold, 100ms timeout, active-high push/pull output, -40°C to +125°C operation, and compatibility with space-constrained embedded designs requiring deterministic reset behavior under fast V_CC transients.

Technical Context

The MAX6803US44D3 implements a precision bandgap-based reset comparator with ±1.8% threshold accuracy at +25°C and ±3% over full temperature range, immune to V_CC transients as short as 30µs at 10V/ms slew rate. Its internal 20kΩ MR pullup eliminates external components for manual reset functionality.

Reset assertion is synchronized to V_CC crossing the 4.38V threshold (falling) or MR low assertion, with a guaranteed 100ms minimum timeout after recovery - fully specified across -40°C to +125°C and validated down to 0.7V V_CC. The push/pull output drives high with 0.8×V_CC VOH at 1µA source current and sinks to ≤0.4V at 3.2mA load.

Key Specifications

Pinout & Package

MAX6803US44D3 is housed in a 4-pin SOT143 package (U4-1 outline), measuring 1.3mm × 2.9mm × 0.95mm, optimized for high-density PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX811TEUS46D3-T and TPS3808G33DBVR, the MAX6803US44D3 uniquely combines 4.38V precision threshold, active-high push/pull output, integrated MR debounce, and 0.7V operational floor-making it optimal for space-constrained µP systems requiring deterministic, self-contained reset control without external components.

Availability

MAX6803US44D3 is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC I/O modules, automotive telematics gateways, and ruggedized handheld terminals requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6803US44D3 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 and mixed-signal ICs for demanding industrial, automotive, and computing applications with emphasis on reliability and integration.

The MAX6803 series delivers single-function, low-power µP supervisory circuits targeting space- and power-sensitive embedded systems where deterministic reset timing and minimal external components are mandatory design requirements.

FAQ

What is the exact reset threshold voltage of MAX6803US44D3 and how is it trimmed?

The MAX6803US44D3 has a factory-trimmed reset threshold of 4.38V, specified with ±1.8% tolerance at +25°C and ±3% over -40°C to +125°C. This value is laser-trimmed during wafer test and verified per Table 1 in the datasheet; the "44" suffix explicitly denotes the 4.38V variant. No external adjustment is possible or required for MAX6803US44D3 operation.

Does MAX6803US44D3 support manual reset, and what is the MR input behavior?

Yes, MAX6803US44D3 features a debounced manual-reset (MR) input on Pin 3. A logic-low signal on MR asserts active-high RESET regardless of V_CC level; RESET remains asserted for the full 100ms timeout after MR returns high. An internal 20kΩ pullup resistor allows MR to be left unconnected if unused, and no external debounce circuitry is needed for MAX6803US44D3.

What is the minimum supply voltage at which MAX6803US44D3 guarantees correct reset output state?

The MAX6803US44D3 guarantees correct RESET output state down to 0.7V V_CC, as confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables. At V_CC ≥ 0.7V, the push/pull output maintains valid VOH ≥ 0.8×V_CC when asserted and VOL ≤ 0.4V when deasserted - a key differentiator from competing supervisors with 1.0V or higher minimums.

How does MAX6803US44D3 handle fast V_CC transients, and what is its immunity specification?

MAX6803US44D3 rejects fast negative-going V_CC transients with propagation delay of 30µs at 10V/ms slew rate. Its reset comparator is designed to ignore glitches shorter than this duration, preventing false resets during switching regulator noise or ESD events. This transient immunity is measured and characterized in the Typical Operating Characteristics section of the MAX6803US44D3 datasheet.

Is MAX6803US44D3 pin-compatible with other members of the MAX6803/MAX6804/MAX6805 family?

Yes, MAX6803US44D3 shares identical 4-pin SOT143 pinout and footprint with all MAX6803, MAX6804, and MAX6805 variants, including MAX6803US26D3-T and MAX6804US44D3-T. Pin 1 = GND, Pin 2 = RESET, Pin 3 = MR, Pin 4 = V_CC; however, output polarity differs between MAX6803 (active-high) and MAX6804/MAX6805 (active-low), so logic-level compatibility must be verified per application for MAX6803US44D3.