Analog Devices Inc./Maxim Integrated MAX6314US31D1+T

Overview

MAX6314US31D1+T from Maxim Integrated is a low-power CMOS microprocessor supervisory circuit that monitors VCC supply voltage and asserts a bidirectional active-low RESET signal when voltage falls below 3.08V or manual reset (MR) is asserted. It features factory-trimmed 3.08V reset threshold, 1ms minimum reset timeout period, ±1.8% threshold accuracy at +25°C, and operates from -40°C to +85°C in SOT143 package. It is used in portable battery-powered equipment requiring reliable power-on reset and brownout protection.

For engineers reviewing the MAX6314US31D1+T datasheet, MAX6314US31D1+T pinout, MAX6314US31D1+T application, or MAX6314US31D1+T equivalent, key selection criteria include reset threshold tolerance, timeout period stability over temperature, MR input glitch rejection (100ns), supply current (5µA typical), and compatibility with bidirectional µP reset I/Os such as the 68HC11.

Technical Context

The MAX6314US31D1+T implements a precision voltage-monitoring comparator with laser-trimmed internal resistive divider to set its 3.08V nominal reset threshold, supported by ±2.5% accuracy over full temperature range. Its reset generator includes an internally programmed 1ms minimum timeout period after VCC recovery or MR deassertion.

RESET output combines a 4.7kΩ pull-up resistor with a p-channel active pullup transistor (enabled for 2µs after RESET release), enabling fast rise time (<350ns into 100pF) and robust interfacing with bidirectional µP reset pins - critical for multi-device reset bus integrity and source-discriminating reset handling in systems like the 68HC11.

Key Specifications

Pinout & Package

SOT143 package: 4-pin, surface-mount, lead-free (indicated by "+T" suffix), -40°C to +85°C operating range.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6315US31D1+T and TPS3808G31DBVR, the MAX6314US31D1+T uniquely integrates a 4.7kΩ pullup + p-channel active pullup to meet strict rise-time requirements of bidirectional µP reset I/Os, making it irreplaceable in 68HC11-class systems without layout changes or external components.

Availability

MAX6314US31D1+T is available at Aetrix Electronics and suitable for portable/battery-powered equipment, critical µP and µC power monitoring, and industrial controllers requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6314US31D1+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 industrial, computing, and communications applications.

The MAX6314 family delivers highly accurate, low-power µP supervisory circuits with factory-trimmed thresholds and integrated bidirectional reset drive - engineered specifically for reliable power sequencing and fault recovery in resource-constrained embedded systems.

FAQ

What is the exact reset threshold voltage of the MAX6314US31D1+T?

The MAX6314US31D1+T 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 calibration. The threshold is monitored directly on the VCC pin using an internal precision voltage divider, and the device asserts RESET whenever VCC falls below this level.

Does the MAX6314US31D1+T support bidirectional reset communication with microcontrollers?

Yes, the MAX6314US31D1+T supports bidirectional reset communication via its specially designed RESET output, which combines a 4.7kΩ pull-up resistor and a p-channel active pullup transistor. This architecture enables µPs like the 68HC11 to assert RESET themselves and detect whether the reset originated externally (from MAX6314US31D1+T) or internally (e.g., watchdog timeout). The 2µs active pullup ensures RESET rises fast enough - within two E-clock cycles - even with multiple devices on the bus.

What is the minimum reset timeout period for the MAX6314US31D1+T?

The MAX6314US31D1+T has a minimum reset timeout period of 1ms. After VCC rises above the 3.08V threshold or after the manual reset (MR) input is deasserted, RESET remains low for at least 1ms before transitioning high. This guaranteed minimum ensures sufficient time for µP core and peripheral initialization. The actual timeout may vary slightly with temperature but remains tightly controlled, with normalized variation of ±0.6% over -40°C to +85°C.

Can the MAX6314US31D1+T operate with VCC below 1.0V?

The MAX6314US31D1+T functions down to VCC = 1.0V, where RESET is guaranteed to sink current and remain a valid logic low. Below 1.0V, RESET becomes high-impedance (open-circuit) and no longer actively drives low. For applications requiring RESET validity down to 0V, a 100kΩ pull-down resistor on the RESET line is recommended - this ensures predictable low state during deep power-down without loading the MAX6314US31D1+T output.

Is the MR input of the MAX6314US31D1+T debounced internally?

Yes, the MR input of the MAX6314US31D1+T includes internal debounce functionality with 100ns glitch rejection. A logic-low pulse shorter than 100ns on MR will not trigger a reset, eliminating false assertions from mechanical switch bounce or EMI. No external RC filter is needed when connecting a momentary switch from MR to GND. For noisy environments or long cable runs, adding a 0.1µF capacitor from MR to GND provides additional immunity without affecting functional timing.