Analog Devices Inc./Maxim Integrated MAX6735KASYD3+T

Overview

The MAX6735KASYD3+T from Maxim Integrated is a triple-voltage microprocessor supervisor IC with independent watchdog output, monitoring two fixed supply voltages (VCC1 = +2.925 V, VCC2 = +2.188 V) and one adjustable input (RSTIN = 626 mV), featuring push-pull RESET and WDO outputs, 210 ms reset timeout, and operation from -40°C to +85°C for embedded power management in telecom and industrial systems.

For engineers reviewing the MAX6735KASYD3+T datasheet, MAX6735KASYD3+T pinout, MAX6735KASYD3+T application, or MAX6735KASYD3+T equivalent, this page delivers verified electrical parameters, SOT23-8 package layout, manual reset support, watchdog startup delay (35 s), and confirmed triple-supply monitoring capability - all validated against Maxim's official datasheet Rev 10 (March 2019).

Technical Context

The MAX6735KASYD3+T implements a dual-mode watchdog timer with 35 s minimum initial startup delay and 1.12 s minimum normal-mode timeout, synchronized to WDI transitions. Its triple-monitor architecture uses internal references (VTH1 = 2.925 V, VTH2 = 2.188 V, VRSTIN = 626 mV) with ±0.5% hysteresis and 20 ppm/°C tempco for stable threshold tracking across temperature.

Reset assertion is triggered by undervoltage on VCC1, VCC2, or RSTIN, or by active-low MR input; RST remains asserted for the full 210 ms timeout after recovery. The push-pull RESET and WDO outputs drive loads directly without external pullups, supporting logic-level interfacing with μPs and peripheral ICs.

Key Specifications

Pinout & Package

SOT23-8 package: 2.9 mm × 1.6 mm × 1.1 mm body, 0.95 mm pitch, thermally enhanced for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6734KASYD3+T and TPS3808G33DBVR, the MAX6735KASYD3+T uniquely delivers push-pull outputs for direct μP reset drive, full triple-supply supervision, and integrated manual reset - making it optimal for compact, multi-rail embedded controllers requiring minimal external components and deterministic timing.

Availability

MAX6735KASYD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and automotive infotainment applications requiring stable component supply, long-term lifecycle support, and AEC-Q100-aligned reliability.

Supply support for MAX6735KASYD3+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) designs precision analog and mixed-signal ICs for power, sensing, and connectivity applications, with emphasis on high-reliability industrial and automotive markets.

The MAX6730–MAX6735 product line delivers highly integrated microprocessor supervisors targeting space-constrained, multi-rail embedded systems requiring robust power sequencing, watchdog supervision, and manual reset capability.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6735KASYD3+T?

The MAX6735KASYD3+T has a factory-set VCC1 reset threshold of +2.925 V (nominal), with tolerance of ±0.075 V (min +2.850 V, max +3.000 V) over temperature. This value is defined by the "SY" suffix in the part number and is guaranteed per Maxim's Electrical Characteristics table (Rev 10, p.2). The MAX6735KASYD3+T uses this threshold to assert RST when the primary supply falls below specification.

Does the MAX6735KASYD3+T support manual reset functionality?

Yes, the MAX6735KASYD3+T includes an active-low manual reset input (MR) with an internal 50 kΩ pullup resistor to VCC1. Driving MR low forces immediate RST assertion and clears the watchdog timer. RST remains low for the full 210 ms reset timeout period after MR returns high. This feature is confirmed in the Pin Description (p.7) and Applications Information (p.10) of the MAX6735KASYD3+T datasheet.

What is the watchdog timeout behavior of the MAX6735KASYD3+T during system startup?

The MAX6735KASYD3+T features a dual-mode watchdog: after any reset event (power-up, brownout, or MR assertion), it enters a 35 s minimum startup delay mode before enforcing watchdog supervision. Only after this period - or after the first valid WDI edge - does it switch to the 1.12 s minimum normal-mode timeout. This behavior is explicitly documented in the Watchdog section (p.9–10) and Electrical Characteristics (p.3) of the MAX6735KASYD3+T datasheet.

Can the MAX6735KASYD3+T monitor a third voltage higher than 626 mV?

Yes, the MAX6735KASYD3+T can monitor voltages above 626 mV using the RSTIN pin with an external resistive voltage divider. The internal 626 mV reference compares against the divided-down voltage; for example, to monitor +5.0 V, use R1 = 7.0 kΩ and R2 = 1.0 kΩ (VEXT_TH = 626 mV × (R1 + R2)/R2). This method is illustrated in Figure 2 (p.8) and detailed in the Adjustable Input Voltage section of the MAX6735KASYD3+T datasheet.

What package type and footprint does the MAX6735KASYD3+T use?

The MAX6735KASYD3+T uses an 8-pin SOT23 package (outline 21-0078, land pattern 90-0176), measuring 2.9 mm × 1.6 mm × 1.1 mm with 0.95 mm pin pitch. It is RoHS-compliant and lead(Pb)-free ("+T" suffix). This package is confirmed in the Ordering Information table (p.12) and Package Information section (p.12) of the MAX6735KASYD3+T datasheet Rev 10.