Analog Devices Inc./Maxim Integrated MAX6734KAWGD3+T

Overview

MAX6734KAWGD3+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 open-drain RST and WDO outputs, 140ms–280ms reset timeout (D3 option), manual reset input (MR), and operates across –40°C to +85°C. It is used in multivoltage embedded systems requiring reliable power-on reset and system lockup protection.

For engineers reviewing the MAX6734KAWGD3+T datasheet, MAX6734KAWGD3+T pinout, MAX6734KAWGD3+T application, or MAX6734KAWGD3+T equivalent, key selection considerations include its dual fixed-voltage thresholds (VCC1/VCC2), third adjustable voltage monitor (RSTIN), 140–280ms reset timeout, open-drain active-low outputs, and SOT23-8 package compatibility with space-constrained industrial and telecom designs.

Technical Context

The MAX6734KAWGD3+T integrates three independent voltage monitors: two factory-set comparators for VCC1 and VCC2, plus a high-impedance RSTIN input with internal 626mV reference. Its reset logic asserts RST low when any monitored voltage falls below its threshold, with hysteresis of 0.5% and tempco of 20ppm/°C.

It implements a dual-mode watchdog timer: 35s minimum startup delay after reset, followed by 1.12s minimum normal-mode timeout. The WDI input clears the timer on any edge; WDO asserts low on timeout or undervoltage conditions. MR forces reset with 200ns propagation delay and internal 50kΩ pullup.

Key Specifications

Pinout & Package

MAX6734KAWGD3+T is housed in an 8-pin SOT23-8 package (JEDEC MO-178AA), with 1.9mm × 2.8mm footprint and 0.95mm height - optimized 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 MAX6734KAWGD3+T, MAX6734KATGD3+T adds automotive qualification without altering electrical function, while TPS3808G33DBVR trades triple supervision and independent WDO for lower cost and current - making it viable only where RSTIN and watchdog isolation are nonessential.

Availability

MAX6734KAWGD3+T is available at Aetrix Electronics and suitable for telecom infrastructure, industrial PLCs, and medical imaging equipment requiring stable component supply, long-lifecycle support, and guaranteed RoHS-compliant sourcing.

Supply support for MAX6734KAWGD3+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, mixed-signal, and power management ICs for demanding industrial, communications, and computing applications.

The MAX6730–MAX6735 family was engineered specifically for multivoltage μP-based systems requiring simultaneous rail monitoring, deterministic reset timing, and independent watchdog fault signaling - targeting high-reliability embedded control and infrastructure equipment.

FAQ

What is the exact reset threshold voltage for VCC1 and VCC2 on the MAX6734KAWGD3+T?

The MAX6734KAWGD3+T has factory-set VCC1 threshold of +3.075V (TW suffix) and VCC2 threshold of +2.313V (ZW suffix), both specified at falling edge with ±1.5% tolerance and 20ppm/°C tempco. These values are laser-trimmed during production and guaranteed over –40°C to +85°C.

Does the MAX6734KAWGD3+T support monitoring a third voltage higher than 0.63V?

Yes - the MAX6734KAWGD3+T includes RSTIN, a high-impedance input with 626mV internal reference. To monitor voltages above 0.63V, connect a resistive divider (e.g., R1=100kΩ, R2=10kΩ) between the target rail and GND, feeding the junction to RSTIN. The external threshold is calculated as VEXT_TH = 626mV × (R1 + R2)/R2.

What is the watchdog timeout behavior of the MAX6734KAWGD3+T during power-up?

The MAX6734KAWGD3+T implements a dual-mode watchdog: after any reset event (power-up, brownout, or MR), it enters a 35s minimum startup period before transitioning to the 1.12s minimum normal timeout. This prevents premature watchdog expiration during lengthy system initialization sequences.

Can the MAX6734KAWGD3+T operate with VCC1 and VCC2 supplied from different sources?

Yes - the MAX6734KAWGD3+T is designed for independent VCC1 and VCC2 supplies. VCC1 powers internal circuitry when >VCC2; otherwise VCC2 takes over. Both rails are monitored simultaneously, and RST asserts if either drops below its threshold - enabling true dual-supply independence in split-rail systems.

Is the MAX6734KAWGD3+T pin-compatible with other devices in the MAX6730–MAX6735 family?

The MAX6734KAWGD3+T uses the SOT23-8 package shared with MAX6734/MAX6735 variants, but pin assignments differ from MAX6730–MAX6733 (SOT23-6). Within the SOT23-8 group, MAX6734KAWGD3+T is pin-compatible with all MAX6734 and MAX6735 variants - including MAX6734KATGD3+T and MAX6735KAxxx+T - differing only in threshold and timeout options.