Analog Devices Inc./Maxim Integrated MAX6314US29D3+T

Overview

MAX6314US29D3+T 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 with bidirectional reset I/Os (e.g., Motorola 68HC11). It features a factory-trimmed reset threshold of 2.93V, a minimum reset timeout period of 140ms, ±2.5% threshold accuracy over temperature, 5µA supply current, and SOT143 package. It is used in portable/battery-powered equipment requiring reliable power-on and brownout reset.

For engineers reviewing the MAX6314US29D3+T datasheet, MAX6314US29D3+T pinout, MAX6314US29D3+T application, or MAX6314US29D3+T equivalent, key selection criteria include bidirectional RESET compatibility, 2.93V threshold tolerance, 140ms minimum timeout, immunity to short VCC transients, and absence of external components for manual reset debouncing.

Technical Context

The MAX6314US29D3+T implements a precision voltage-monitoring comparator with laser-trimmed internal resistors to set its 2.93V reset threshold, and an internal timer that guarantees RESET remains asserted for ≥140ms after VCC rises above threshold or MR deasserts. Its bidirectional RESET output combines a 4.7kΩ pull-up resistor with a P-channel active pullup transistor, enabling fast rise time (<35ns typical) even under high capacitive load conditions typical in multi-device reset buses.

This device operates across -40°C to +85°C, draws only 5µA at +25°C, and maintains reset assertion down to VCC = 1V. The MR input includes a 63kΩ internal pullup, allowing direct connection of a momentary switch to GND without external components, while remaining immune to transients ≤100ns at 100mV overdrive.

Key Specifications

Pinout & Package

SOT143 (4-pin, surface-mount) package with 1.3mm × 2.1mm footprint, 0.95mm height, and gull-wing leads. RoHS-compliant lead-free finish (indicated by "+T" suffix).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6314US29D3+T, MAX6315US29D3+T removes the active pullup but retains identical monitoring specs-making it suitable only for non-bidirectional interfaces-while TPS3808G33DBVR trades bidirectionality and threshold flexibility for lower quiescent current and tighter 3.3V tolerance, limiting its use to fixed-rail designs.

Availability

MAX6314US29D3+T is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC controllers, smart energy meters, and automotive body control modules requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6314US29D3+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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and consumer applications.

The MAX6314 family was designed specifically for µP-based systems requiring precise, low-power, and bidirectional-capable reset supervision-targeting applications where reset source identification and minimal external components are critical.

FAQ

What is the exact reset threshold voltage of the MAX6314US29D3+T?

The MAX6314US29D3+T has a factory-trimmed nominal reset threshold of 2.93V, with ±2.5% accuracy over the full operating temperature range (-40°C to +85°C). This value is laser-trimmed during production and does not require external adjustment. The MAX6314US29D3+T is specified to assert RESET when VCC falls below this threshold and hold it active for ≥140ms after VCC rises above it.

Does the MAX6314US29D3+T require an external pull-up resistor on the RESET pin?

No, the MAX6314US29D3+T does not require an external pull-up resistor. It integrates a 4.7kΩ pull-up resistor in parallel with a P-channel active pullup transistor on the RESET pin, enabling direct interface with bidirectional reset I/Os such as those found on the Motorola 68HC11. This internal structure eliminates external components while ensuring fast rise time under capacitive loads.

Can the MAX6314US29D3+T be used with microcontrollers that have open-drain reset inputs?

Yes, the MAX6314US29D3+T is fully compatible with open-drain reset inputs. Its RESET output functions as an enhanced open-drain structure: it actively pulls low via an N-channel transistor and pulls high via the integrated 4.7kΩ resistor and P-channel transistor. When connected to an open-drain input, the MAX6314US29D3+T behaves identically to a standard open-drain supervisor, with no risk of contention or damage.

What is the minimum VCC voltage at which the MAX6314US29D3+T guarantees RESET assertion?

The MAX6314US29D3+T guarantees RESET remains asserted for VCC > 1.0V (as specified in Electrical Characteristics). Below 1.0V, the internal circuitry ceases to sink current and RESET becomes high-impedance. For applications requiring valid RESET down to 0V, a 100kΩ pull-down resistor on the RESET line is recommended to prevent floating states during deep undervoltage conditions.

How does the manual reset (MR) input of the MAX6314US29D3+T work, and what external components are needed?

The MR input of the MAX6314US29D3+T is active-low with an internal 63kΩ pullup resistor, so it can be left unconnected if unused. To implement manual reset, connect a normally open momentary switch between MR and GND. No external debounce components are required-the MAX6314US29D3+T inherently rejects transients <100ns. In noisy environments, a 0.1µF capacitor from MR to GND adds further immunity.