Analog Devices Inc./Maxim Integrated MAX6723UTVDD3+

Overview

MAX6723UTVDD3+ from Maxim Integrated is a triple-voltage microprocessor supervisory circuit in 6-pin SOT23 package, monitoring VCC1 (4.625V threshold), VCC2 (3.075V threshold), and an externally adjustable RSTIN input (626.5mV reference). It asserts active-low open-drain reset for ≥210ms after any monitored supply drops below threshold or manual reset is triggered, and supports watchdog timer startup (35s) and normal mode (1.12s). Used in multivoltage telecom and industrial systems requiring reliable power sequencing and brownout protection.

For engineers reviewing the MAX6723UTVDD3+ datasheet, MAX6723UTVDD3+ pinout, MAX6723UTVDD3+ application, or MAX6723UTVDD3+ equivalent, key selection factors include its dual-supply monitoring with factory-trimmed thresholds, RSTIN-based third-voltage supervision down to 0.62V, guaranteed reset validity at VCC1/VCC2 ≥ 0.8V, low 14µA typical supply current, and SOT23-6 footprint compatibility with space-constrained embedded designs.

Technical Context

The MAX6723UTVDD3+ implements independent voltage comparators for VCC1 and VCC2 with ±1.5% threshold accuracy and 20ppm/°C tempco, plus a high-impedance RSTIN comparator referenced to a 626.5mV internal bandgap. Its reset timeout is fixed at 210ms (min), generated by an on-chip RC oscillator calibrated across temperature.

It features an open-drain RST output referenced to VCC1, a manual reset input (MR) with 50kΩ internal pullup to VCC1 and 1µs minimum pulse width support, and watchdog functionality with dual-mode timing-35s initial startup window followed by 1.12s normal timeout-triggered by WDI edge transitions.

Key Specifications

Pinout & Package

MAX6723UTVDD3+ uses a 6-pin SOT23-6 package (2.9mm × 1.6mm × 1.1mm), surface-mount, lead-free (+ suffix), RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar triple-voltage supervisory applications.

Compared with MAX6723UTVDD3+, MAX6724UTVDD3+ offers push-pull drive for simpler interfacing but sacrifices bus-sharing flexibility, while TPS3808G33DBVR reduces feature set and monitoring scope-making it viable only when third-rail supervision is unnecessary and layout space is constrained.

Availability

MAX6723UTVDD3+ is available at Aetrix Electronics and suitable for telecom infrastructure, industrial control, and portable medical equipment requiring stable component supply, long-term lifecycle assurance, and guaranteed lead-free compliance.

Supply support for MAX6723UTVDD3+ 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6715–MAX6729 family was designed to replace discrete reset circuits in multivoltage embedded systems-delivering compact, accurate, and low-power supervision with configurable monitoring depth and timing.

FAQ

What is the exact reset threshold voltage for VCC1 on MAX6723UTVDD3+?

The MAX6723UTVDD3+ has a factory-trimmed VCC1 reset threshold of 4.625V (minimum 4.500V, maximum 4.750V at +25°C), with ±1.5% tolerance over temperature. This value is encoded in the "TD" suffix per Maxim's Reset Voltage Threshold Suffix Guide and applies specifically to the MAX6723UTVDD3+ variant-not the broader MAX6723 family.

Does MAX6723UTVDD3+ support monitoring a third voltage, and how is it configured?

Yes, MAX6723UTVDD3+ supports third-voltage monitoring via its RSTIN pin, which compares the applied voltage against a 626.5mV internal reference. To monitor a higher voltage (e.g., 12V), connect a resistor divider between the supply and GND, with the midpoint fed to RSTIN. The threshold is calculated as V_EXT = 626.5mV × (R1 + R2)/R2, where R2 connects to GND.

What is the watchdog timeout behavior of MAX6723UTVDD3+ after power-up?

After power-up or any reset event, MAX6723UTVDD3+ enters a 35-second (minimum) long-startup watchdog mode. Once the first valid WDI edge occurs within that window, it switches to normal 1.12-second (minimum) timeout operation. This prevents false timeouts during boot sequences while ensuring rapid detection of runtime hangs.

Is MAX6723UTVDD3+ compatible with bidirectional microprocessor reset pins?

Yes, MAX6723UTVDD3+ features an open-drain RST output, making it directly compatible with bidirectional µP reset I/O pins. No series resistor is required for basic interface, though a 4.7kΩ resistor is recommended in noisy environments to prevent contention when the µP drives reset low during normal operation.

What is the minimum operating voltage for guaranteed reset functionality on MAX6723UTVDD3+?

MAX6723UTVDD3+ guarantees correct reset output logic state as long as either VCC1 or VCC2 remains above 0.8V. Below this level, reset behavior is not specified-so system designers must ensure at least one supply stays ≥0.8V during brownout conditions to maintain deterministic supervision.