Analog Devices Inc./Maxim Integrated MAX6735KARVD3+T

Overview

MAX6735KARVD3+T from Maxim Integrated is a triple-voltage microprocessor supervisor IC with independent watchdog output, monitoring VCC1 (+3.075V nominal), VCC2 (+2.313V nominal), and an adjustable RSTIN input (626mV threshold). It features push-pull RESET and WDO outputs, 140–280ms reset timeout, and operates across –40°C to +85°C. Used in multivoltage embedded systems requiring reliable power-on reset and processor lockup detection.

For engineers reviewing the MAX6735KARVD3+T datasheet, MAX6735KARVD3+T pinout, MAX6735KARVD3+T application, or MAX6735KARVD3+T equivalent, key selection criteria include its dual fixed-threshold supervision (VCC1/VCC2), third adjustable voltage monitor, push-pull active-low reset and watchdog outputs, 14µA typical supply current, and SOT23-8 package compatibility with space-constrained industrial and telecom designs.

Technical Context

The MAX6735KARVD3+T implements three independent voltage monitors: a factory-set +3.075V threshold on VCC1, +2.313V on VCC2, and a precision 626mV reference for RSTIN-enabling external resistive division to supervise voltages down to +0.63V. Its reset assertion logic combines undervoltage detection across all three inputs with manual reset (MR) and watchdog timeout events.

It integrates a dual-mode watchdog timer: a 35s minimum startup delay after reset ensures safe system initialization, followed by a 1.12s minimum normal-mode timeout. The push-pull RST and WDO outputs drive loads directly without external pullups, while MR includes a 50kΩ internal pullup and supports TTL/CMOS-level triggering with 1µs minimum pulse width.

Key Specifications

Pinout & Package

MAX6735KARVD3+T is housed in an 8-pin SOT23 package (K8SN+1 outline), measuring 2.9mm × 1.6mm × 1.1mm, optimized for high-density PCB layouts in portable and industrial equipment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6734KARVD3+T, the MAX6735KARVD3+T eliminates external pullup components and simplifies layout; versus TPS3808G33DBVR, it delivers essential triple-rail supervision and design flexibility at the cost of higher pin count and slightly increased BOM complexity.

Availability

MAX6735KARVD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial automation, and medical device applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6735KARVD3+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 demanding industrial, automotive, and communications applications.

The MAX6730–MAX6735 family targets robust power-management supervision in multivoltage embedded systems, emphasizing reliability under brownout, transient immunity, and integrated watchdog functionality for safety-critical firmware monitoring.

FAQ

What is the exact reset threshold voltage for VCC1 on the MAX6735KARVD3+T?

The MAX6735KARVD3+T has a factory-set VCC1 reset threshold of +3.075V (nominal), corresponding to the "R" suffix in its ordering code. Electrical characteristics specify a min/max range of +3.000V to +3.150V at 25°C, with ±20ppm/°C tempco and 0.5% hysteresis referenced to typical threshold. This value is laser-trimmed during production and guaranteed over –40°C to +85°C.

Does the MAX6735KARVD3+T support monitoring a third voltage rail, and how is it configured?

Yes, the MAX6735KARVD3+T supports third-rail monitoring via its RSTIN pin, which features a precise 626mV internal reference. To supervise a higher voltage (e.g., +5V or +12V), connect a resistive divider between the rail and GND, with the midpoint fed to RSTIN. The divider ratio must satisfy V_{EXT_TH} = 626mV × (R1 + R2)/R2. RSTIN draws only ±25nA, enabling high-resistance dividers to minimize power loss.

What are the watchdog timeout periods for the MAX6735KARVD3+T, and how do they operate?

The MAX6735KARVD3+T uses a dual-mode watchdog: a 35s minimum startup delay begins after each reset event (power-up, brownout, or MR assertion), allowing full system initialization; then a 1.12s minimum normal timeout takes effect after the first valid WDI edge. Both periods are guaranteed over temperature and supply voltage, and WDO asserts low if no WDI transition occurs within the active timeout window.

Is the MAX6735KARVD3+T compatible with bidirectional microprocessor reset pins?

Yes, but requires a 10kΩ series resistor between RST and the µP's bidirectional reset I/O port to prevent logic contention. The MAX6735KARVD3+T's push-pull RST output actively drives high/low states, unlike open-drain alternatives. Without the resistor, simultaneous drive conflicts could cause excessive current or undefined logic levels during reset release or firmware-controlled reset assertion.

What package type and RoHS status does the MAX6735KARVD3+T use?

The MAX6735KARVD3+T uses an 8-pin SOT23 package (outline K8SN+1) with 2.9mm × 1.6mm footprint and 1.1mm height. The "+T" suffix confirms it is lead(Pb)-free and RoHS-compliant, with solder reflow profile rated to +260°C. Thermal resistance is θ_JA = 180°C/W and θ_JC = 60°C/W, supporting operation up to +85°C ambient without derating.