Analog Devices Inc./Maxim Integrated MAX6446UK31L+TG65

Overview

The MAX6446UK31L+TG65 from Maxim Integrated is a dual-input, fixed-threshold microprocessor supervisor IC with active-low open-drain RESET output, 3.075V VCC reset threshold, and 6.72s extended manual reset setup period (tMR). It monitors a single supply (VCC), asserts RESET when voltage drops below threshold or when both MR1 and MR2 are held low ≥6.72s, and guarantees valid reset down to VCC = 1.0V. Used in set-top boxes and cable modems for reliable power-on and brownout protection.

For engineers reviewing the MAX6446UK31L+TG65 datasheet, MAX6446UK31L+TG65 pinout, MAX6446UK31L+TG65 application, or MAX6446UK31L+TG65 equivalent, key selection criteria include its dual extended-setup manual reset architecture, 3.075V precision reset threshold, 6.72s tMR timing, SOT23-5 package, and immunity to <20µs transients at 100mV overdrive - critical for front-panel switch interfacing in consumer electronics.

Technical Context

This device implements a dual manual reset input architecture where both MR1 and MR2 must be held low simultaneously for ≥6.72s to trigger a one-shot 140ms–280ms RESET pulse. Its internal 50kΩ pullup on each MR pin enables direct connection to mechanical switches without external components.

The reset comparator features 60ppm/°C tempco and 2×VTH hysteresis, ensuring stable 3.075V threshold operation across –40°C to +85°C. RESET remains asserted for 210ms (typ) after VCC recovers above threshold, providing sufficient deassertion hold time for microprocessor initialization.

Key Specifications

Pinout & Package

MAX6446UK31L+TG65 is housed in a 5-pin SOT23 package (U5+1 outline), footprint-compatible with industry-standard 5-lead SOT-23 layouts and suitable for high-density PCB designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6445UK31L+T, the MAX6446UK31L+TG65 adds G65 tape-and-reel packaging and traceability compliance; versus TPS3808G33DBVR, it delivers deterministic long-duration manual reset coordination essential for consumer UI safety - not achievable with standard debounce-based alternatives.

Availability

MAX6446UK31L+TG65 is available at Aetrix Electronics and suitable for set-top boxes, cable modems, and MP3 players requiring stable component supply, long-term lifecycle support, and automotive-grade traceability.

Supply support for MAX6446UK31L+TG65 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 industrial, communications, and consumer applications.

The MAX6443–MAX6452 family delivers microprocessor reset supervision with extended manual reset setup periods, targeting front-panel switch interfaces in consumer electronics where nuisance resets must be eliminated.

FAQ

What is the exact reset threshold voltage for MAX6446UK31L+TG65?

The MAX6446UK31L+TG65 has a factory-trimmed VCC reset threshold of 3.075V, with ±0.075V tolerance over temperature. This value is confirmed in Table 1 of the datasheet under suffix "31", and ensures precise brownout detection for 3.3V systems without requiring external calibration. The MAX6446UK31L+TG65 maintains this threshold with 60ppm/°C tempco across –40°C to +85°C.

How does the dual manual reset function work on MAX6446UK31L+TG65?

The MAX6446UK31L+TG65 requires both MR1 and MR2 pins to be held low simultaneously for ≥6.72 seconds (L suffix) to assert the RESET output. This dual-input extended setup prevents accidental resets from single-button presses. Internal 50kΩ pullups eliminate need for external resistors, and the one-shot RESET pulse lasts 140ms minimum. This behavior is exclusive to MAX6445/MAX6446 variants - not present in single-MR devices like MAX6443.

Is MAX6446UK31L+TG65 compatible with 1.8V microcontrollers?

Yes - the MAX6446UK31L+TG65's open-drain RESET output can interface with 1.8V logic when pulled up to a 1.8V rail using a ≥20kΩ resistor. However, its VCC supply must remain within 1.0V–5.5V, and the 3.075V reset threshold applies only to the monitored VCC rail, not the pullup voltage. The MAX6446UK31L+TG65 itself does not monitor 1.8V supplies; for that, use MAX6449–MAX6452 with RSTIN.

What package type and footprint does MAX6446UK31L+TG65 use?

MAX6446UK31L+TG65 uses a 5-pin SOT23 package (U5+1 outline, land pattern 90-0174), with pin 1 = GND, pin 2 = VCC, pin 3 = MR1, pin 4 = RESET, and pin 5 = MR2. It is RoHS-compliant (G65 denotes lead-free tape-and-reel), and shares footprint compatibility with other SOT23-5 supervisors like TPS3808 series - enabling drop-in replacement in many designs.

Does MAX6446UK31L+TG65 meet automotive qualification standards?

No - MAX6446UK31L+TG65 is rated for –40°C to +85°C operation but is not AEC-Q100 qualified. Automotive-grade equivalents include MAX6444US16K/V+T (SOT143, 1.575V threshold) and MAX6446UK31L/V+T (same specs with /V suffix). The "G65" suffix indicates lead-free tape-and-reel packaging only; automotive qualification requires explicit /V in the part number per Maxim's ordering guide.