Analog Devices Inc./Maxim Integrated MAX6730AUTVD3+T

Overview

MAX6730AUTVD3+T from Maxim Integrated is a single-voltage microprocessor supervisor IC with active-low open-drain reset output, factory-set +3.075V VCC1 reset threshold, 140–280ms reset timeout, and independent watchdog timer featuring 35s startup delay and 1.12s normal timeout. It monitors primary supply voltage only and supports manual reset input, enabling reliable power-on initialization and lockup recovery in embedded control systems.

For engineers reviewing the MAX6730AUTVD3+T datasheet, MAX6730AUTVD3+T pinout, MAX6730AUTVD3+T application, or MAX6730AUTVD3+T equivalent, this device delivers deterministic reset assertion under brownout, precise timing for system boot sequencing, low 14µA supply current at +3.6V, and immunity to sub-100ns VCC transients - critical for industrial PLCs, telecom line cards, and battery-backed instrumentation.

Technical Context

The MAX6730AUTVD3+T implements a dual-mode watchdog architecture: a 35s (min) initial timeout after reset enables full system initialization, followed by a 1.12s (min) short-period mode for rapid fault detection during runtime. Its reset comparator guarantees valid operation down to VCC1 = +0.8V and features 20ppm/°C tempco and 0.5% hysteresis referenced to typical threshold.

Reset assertion occurs when VCC1 falls below +3.075V (±75mV), with 45µs propagation delay from threshold crossing to RST output. The manual reset input (MR) includes a 50kΩ internal pullup, 1µs minimum pulse width support, and 100ns glitch rejection - ensuring robust external reset triggering without external components.

Key Specifications

Pinout & Package

MAX6730AUTVD3+T is housed in a 6-pin SOT23-6 package (U6-1), measuring 2.9mm × 1.6mm × 1.1mm, with gull-wing leads and RoHS-compliant lead-free finish (+T suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6730AUTVD3+T, MAX6326UTR33+T trades watchdog capability for push-pull output simplicity, while TPS3808G33DBVR reduces feature count to minimize footprint - making MAX6730AUTVD3+T the optimal choice when integrated watchdog supervision and manual reset are mandatory for system reliability.

Availability

MAX6730AUTVD3+T is available at Aetrix Electronics and suitable for industrial PLC controllers, telecom line cards, and portable medical monitors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6730AUTVD3+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 MAX6730A–MAX6735A family targets multivoltage embedded systems needing coordinated reset sequencing, brownout immunity, and autonomous watchdog supervision - especially where space, power, and temperature resilience are critical.

FAQ

What is the exact reset threshold voltage for MAX6730AUTVD3+T?

The MAX6730AUTVD3+T has a factory-set VCC1 reset threshold of +3.075V, with a tolerance of ±75mV (i.e., +3.000V to +3.150V) over the full −40°C to +125°C operating range. This value is fixed by the "V" suffix in the part number per Maxim's Reset Voltage Threshold Suffix Guide and is not adjustable. The threshold applies exclusively to the VCC1 pin; the device does not monitor VCC2 or RSTIN.

Does MAX6730AUTVD3+T support manual reset, and how is it implemented?

Yes, MAX6730AUTVD3+T includes an active-low manual reset input (MR) on pin 4. It features an internal 50kΩ pullup resistor to VCC1, so the pin may be left floating if unused. Driving MR low forces immediate RST assertion for the full reset timeout period (140–280ms), then holds RST low for the duration even after MR returns high. The input accepts CMOS logic levels and rejects glitches shorter than 100ns.

What watchdog timeout periods does MAX6730AUTVD3+T provide?

MAX6730AUTVD3+T implements a dual-mode watchdog: a minimum 35s startup timeout after any reset event (power-up, brownout, or MR assertion), followed by a minimum 1.12s normal timeout once the first valid edge is detected on WDI. The watchdog output (WDO) is active-low open-drain and asserts if WDI remains static beyond the applicable timeout - providing layered protection against boot failures and runtime hangs.

Is MAX6730AUTVD3+T compatible with bidirectional microprocessor reset pins?

Yes, MAX6730AUTVD3+T is fully compatible with bidirectional µP reset pins due to its open-drain RST output (pin 1). This configuration avoids logic contention that can occur with push-pull supervisors. No series resistor is required - simply connect RST directly to the µP's bidirectional reset I/O, with an external pullup (typically 10kΩ) to the µP's VDD_IO rail.

What is the supply current consumption of MAX6730AUTVD3+T at +3.6V?

At +3.6V and +25°C, MAX6730AUTVD3+T draws 14µA typical supply current (ICC1), with a maximum of 39µA over temperature. This ultra-low quiescent current is measured with all I/Os open and outputs not asserted. Total current remains stable across −40°C to +125°C, making it ideal for battery-operated and energy-sensitive applications where standby power budget is critical.