Analog Devices Inc./Maxim Integrated MAX6746KA31/V+T

Overview

MAX6746KA31/V+T from Analog Devices is a low-power microprocessor supervisory circuit with factory-trimmed 3.075V ±2% VCC reset threshold, capacitor-adjustable 5.69–9.49ms reset timeout, and normal-mode watchdog timeout (5.69–9.49ms), all operating across -40°C to +125°C. It features push-pull active-low RESET output, manual-reset input (MR), and immunity to power-supply transients - used in automotive engine control units to ensure deterministic μP restart during cold-crank brownout events.

For engineers reviewing the MAX6746KA31/V+T datasheet, MAX6746KA31/V+T pinout, MAX6746KA31/V+T application, or MAX6746KA31/V+T equivalent, key selection criteria include its AEC-Q100 qualification, 3.7µA supply current at 1.8V, dual-voltage monitoring capability (VCC + RESET IN), adjustable reset/watchdog timing via external capacitors, and compatibility with 1.0V–5.5V VCC operation.

Technical Context

The MAX6746KA31/V+T implements a precision bandgap-based reset comparator with 3.075V nominal threshold (±2% over -40°C to +125°C) and 0.8% hysteresis, guaranteeing valid RESET assertion down to VCC = 1V. Its reset timeout is set by an external capacitor on SRT pin using t_RP = 4.94 × 10⁶ × C_SRT (seconds).

It integrates a standard watchdog timer with capacitor-adjustable timeout (t_WD = 4.94 × 10⁶ × C_SWT) and WDS pin for 128× extended mode. MR input includes 1μs minimum pulse width requirement and 100ns glitch rejection, with internal VCC pullup eliminating need for external resistor.

Key Specifications

Pinout & Package

MAX6746KA31/V+T is housed in an 8-pin SOT23 package (outline 21-0078, land pattern 90-0176), RoHS-compliant, with 0.65mm pitch and 2.9mm × 1.6mm footprint - optimized for space-constrained automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6747KA31/V+T, the MAX6746KA31/V+T provides direct-drive reset capability without external pullup, simplifying layout; versus TLV803EB31DBVR, it adds essential watchdog and manual reset functions required for ASIL-B automotive software safety goals.

Availability

MAX6746KA31/V+T is available at Aetrix Electronics and suitable for automotive engine control, ADAS camera modules, and telematics control units requiring stable component supply across extended temperature and long product lifecycles.

Supply support for MAX6746KA31/V+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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving automotive, industrial, communications, and healthcare markets.

The MAX6746–MAX6753 family delivers AEC-Q100-qualified, low-power μP supervisors with configurable reset/watchdog timing for automotive safety-critical electronic control units and battery-powered embedded systems.

FAQ

What is the factory-trimmed reset threshold voltage of the MAX6746KA31/V+T?

The MAX6746KA31/V+T has a factory-trimmed VCC reset threshold of 3.075V with ±2% tolerance over -40°C to +125°C, corresponding to suffix "31" per Table 2 in the datasheet. This value is laser-trimmed during production and does not require external resistor networks for accuracy. The MAX6746KA31/V+T guarantees this threshold remains stable across automotive temperature extremes and supply voltage variations from 1.0V to 5.5V.

Does the MAX6746KA31/V+T support dual-voltage monitoring?

No, the MAX6746KA31/V+T monitors only the VCC supply voltage using its factory-trimmed 3.075V threshold. It does not include the adjustable RESET IN input found in MAX6748–MAX6751 variants. Dual-voltage monitoring requires either MAX6750KA31/V+T (which adds RESET IN) or external resistor-divider implementation - the MAX6746KA31/V+T is strictly a single-rail VCC supervisor with manual reset and watchdog functionality.

What is the maximum watchdog timeout period achievable with the MAX6746KA31/V+T?

The MAX6746KA31/V+T supports up to 1214.4ms watchdog timeout in extended mode (WDS = VCC) with CSWT = 1500pF, calculated as t_WD × 128 = 9.487ms × 128. In normal mode (WDS = GND), maximum timeout is 9.487ms. The device uses t_WD = 4.94 × 10⁶ × C_SWT (seconds), so a 0.1µF capacitor yields ~494ms in normal mode. The MAX6746KA31/V+T does not support windowed watchdog operation - that feature is exclusive to MAX6752/MAX6753.

Is the MAX6746KA31/V+T pin-compatible with other devices in the MAX6746–MAX6753 family?

The MAX6746KA31/V+T shares the same 8-pin SOT23 package and pinout as MAX6746–MAX6751 variants, including identical MR, WDS, SWT, SRT, GND, WDI, RESET, and VCC assignments. However, pin functionality differs for MAX6752/MAX6753 (which replace WDS with SET0/SET1). Thus, MAX6746KA31/V+T is pin-compatible with MAX6747KA31/V+T and MAX6748KA31/V+T, but not with MAX6752/MAX6753 - direct replacement requires schematic and firmware review.

What is the supply current specification of the MAX6746KA31/V+T at 3.3V VCC?

At VCC ≤ 3.3V, the MAX6746KA31/V+T draws 4.2µA (minimum) to 9µA (maximum) supply current over -40°C to +125°C, with 5µA typical. This ultra-low quiescent current enables use in always-on automotive subsystems such as door modules and occupancy sensors where battery drain must remain below 10µA. The MAX6746KA31/V+T achieves this while maintaining full reset accuracy, watchdog functionality, and AEC-Q100 qualification.