Analog Devices Inc./Maxim Integrated MAX6314US31D3

Overview

MAX6314US31D3 from Maxim Integrated is a low-power CMOS microprocessor supervisory circuit designed to monitor VCC supply voltage and assert a bidirectional reset signal for µPs like the 68HC11. It features a factory-trimmed 3.08V reset threshold, 140ms minimum reset timeout period, ±1.8% threshold accuracy at +25°C, 5µA supply current, and SOT143 package. It enables reliable power-up/power-down sequencing in battery-powered controllers and embedded systems.

For engineers reviewing the MAX6314US31D3 datasheet, MAX6314US31D3 pinout, MAX6314US31D3 application, or MAX6314US31D3 equivalent, key selection criteria include its bidirectional RESET output architecture, 3.08V VTH tolerance over temperature, 140ms timeout timing, immunity to short VCC transients, and compatibility with manual reset assertion without external debounce.

Technical Context

The MAX6314US31D3 implements a precision voltage-monitoring comparator with laser-trimmed internal resistive divider to set its 3.08V reset threshold, with ±2.5% accuracy across –40°C to +85°C. Its reset generator uses an internal timer that guarantees minimum 140ms assertion after VCC recovery or MR deassertion.

RESET output combines a 4.7kΩ pullup resistor and P-channel active pullup transistor (enabled for 2µs after low-to-high transition), enabling fast rise time on capacitive reset buses-critical for multi-device systems using bidirectional reset I/Os such as the 68HC11. MR input includes a 63kΩ internal pullup and accepts logic-low manual reset pulses ≥1µs.

Key Specifications

Pinout & Package

SOT143 (4-pin, 1.3mm × 2.9mm, 0.95mm height) surface-mount package rated for –40°C to +85°C operation. Lead-free and leaded variants available.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6314US31D3, MAX6315US31D3 omits the integrated pullup-increasing BOM cost and layout area for bidirectional systems-while TPS3808G30DBVR trades MR capability and precise 3.08V threshold for lower quiescent current and smaller footprint, limiting use in legacy 68HC11-based designs.

Availability

MAX6314US31D3 is available at Aetrix Electronics and suitable for industrial controllers, portable medical devices, automotive body electronics, and smart energy meters requiring stable component supply, long-term lifecycle support, and guaranteed reset timing under brownout conditions.

Supply support for MAX6314US31D3 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 interface applications in industrial, automotive, and computing markets.

The MAX6314 product line delivers highly accurate, low-power µP supervisory circuits optimized for systems requiring factory-trimmed reset thresholds, bidirectional reset compatibility, and minimal external components-targeting cost-sensitive, space-constrained embedded control applications.

FAQ

What is the exact reset threshold voltage of the MAX6314US31D3?

The MAX6314US31D3 has a factory-trimmed nominal reset threshold voltage of 3.08V, with ±1.8% accuracy at +25°C and ±2.5% over the full –40°C to +85°C operating temperature range. This value is laser-trimmed during manufacturing and does not require external adjustment. The 3.08V threshold is specifically selected to provide robust undervoltage detection for 3.3V digital systems while avoiding false trips near nominal rail tolerances.

Does the MAX6314US31D3 support bidirectional reset interfaces like the 68HC11?

Yes, the MAX6314US31D3 is explicitly designed for bidirectional reset I/Os such as those found on the Motorola 68HC11. Its RESET pin integrates both an N-channel pulldown and a P-channel active pullup in parallel with a 4.7kΩ resistor, enabling µPs to drive the line low while ensuring fast, reliable rise time-even with multiple devices on the same reset bus. This architecture eliminates the need for external pullup components in compatible systems.

What is the minimum reset timeout period for the MAX6314US31D3?

The MAX6314US31D3 provides a minimum reset timeout period of 140ms after VCC rises above the 3.08V threshold or after the manual reset (MR) input is deasserted. This fixed timeout is internally programmed and guaranteed across temperature and supply voltage variations. It ensures sufficient hold time for microprocessors and peripherals to stabilize before releasing reset, preventing premature code execution in complex embedded systems.

Can the MAX6314US31D3 operate down to 1.0V supply voltage?

Yes, the MAX6314US31D3 operates over a VCC range of 1.0V to 5.5V and guarantees RESET remains a valid logic low for VCC > 1.0V. Below 1.0V, RESET becomes high-impedance, but this behavior is intentional-most µPs are nonfunctional below 1.0V, so no active reset assertion is required. For applications needing RESET validity down to 0V, a 100kΩ external pull-down resistor on the RESET line is recommended per the datasheet.

Is manual reset debouncing required for the MAX6314US31D3?

No, the MAX6314US31D3 includes built-in manual reset debouncing. Its MR input features a 100ns glitch rejection window and accepts logic-low pulses as short as 1µs, eliminating the need for external RC filters or firmware debouncing. An internal 63kΩ pullup resistor allows MR to be left floating if unused. In noisy environments or with long PCB traces, adding a 0.1µF capacitor from MR to GND provides additional immunity without compromising response time.