Analog Devices Inc./Maxim Integrated MAX6315US45D3+

Overview

MAX6315US45D3+ from Maxim Integrated is a low-power CMOS microprocessor supervisory circuit that monitors VCC supply voltage and asserts an open-drain active-low RESET signal when voltage falls below 4.50V or upon manual reset assertion. It provides factory-trimmed 4.50V reset threshold, 140ms minimum reset timeout period, 5µA supply current, and operates from -40°C to +125°C in SOT143 package. Used for reliable power-on reset in battery-powered controllers and critical µP systems.

For engineers reviewing the MAX6315US45D3+ datasheet, MAX6315US45D3+ pinout, MAX6315US45D3+ application, or MAX6315US45D3+ equivalent, key selection criteria include precise 4.50V threshold tolerance (±3.5%), open-drain output capable of level-shifting above VCC, immunity to short VCC transients, guaranteed operation over industrial temperature range, and compatibility with manual reset switch interfaces without external debounce.

Technical Context

The MAX6315US45D3+ implements a precision voltage-monitoring comparator with laser-trimmed internal resistive divider to set the 4.50V nominal reset threshold, with ±3.5% accuracy over -40°C to +125°C. Its internal timer generates a fixed 140ms (min) reset pulse after VCC rises above threshold or MR deasserts.

It features an open-drain n-channel MOSFET RESET output rated to sink 0.5mA at 0.4V, compatible with pull-up voltages up to +6.0V - enabling level-shifted reset signaling across different supply domains. The MR input includes a 63kΩ internal pull-up resistor and rejects glitches <100ns.

Key Specifications

Pinout & Package

SOT143 (4-pin, surface-mount) package with 1.3mm × 2.1mm footprint and 0.95mm height; lead-free per RoHS, tape-and-reel packaging only.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6315US45D2+, the MAX6315US45D3+ provides 7× longer reset assertion for robust initialization; versus TLV803EB45DBZR, it adds MR functionality and SOT143 pinout compatibility with legacy Maxim designs, at the cost of larger footprint and no 1.8V operation.

Availability

MAX6315US45D3+ is available at Aetrix Electronics and suitable for industrial PLC controllers, battery-powered data loggers, automotive body control modules, and medical handheld diagnostics requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6315US45D3+ 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 industrial, automotive, communications, and computing applications.

The MAX6315 family delivers highly accurate, low-power supervisory circuits optimized for reliable µP reset generation in harsh environments - emphasizing factory-trimmed thresholds, wide temperature operation, and noise-immune timing.

FAQ

What is the exact reset threshold voltage and tolerance for MAX6315US45D3+?

The MAX6315US45D3+ has a nominal reset threshold of 4.50V with a tolerance of ±3.5% over the full operating temperature range (-40°C to +125°C), meaning the actual trip point falls between 4.34V and 4.66V. This specification is guaranteed by laser trimming during manufacturing and confirmed in the Electrical Characteristics table under "Reset Threshold" for the D3-T/D3+ variant.

Does MAX6315US45D3+ require an external pull-up resistor on the RESET pin?

Yes, the MAX6315US45D3+ features an open-drain RESET output and requires an external pull-up resistor. A typical value is 10kΩ connected to a logic supply (up to +6.0V). The resistor must be sized to ensure the RESET line reaches a valid logic-high level while sinking the specified 0.5mA load current when asserted - details are provided in the "RESET Output Voltage" and "RESET Output Leakage Current" parameters of the datasheet.

Can MAX6315US45D3+ operate with VCC below 4.50V and still function correctly?

Yes, the MAX6315US45D3+ operates with VCC as low as 1.0V and remains functional down to that level. It asserts RESET whenever VCC falls below 4.50V and continues asserting until VCC rises above threshold and the 140ms timeout expires. Its ability to sink RESET current degrades below 1V, but the device guarantees RESET remains low for VCC > 1V - enabling reliable brownout detection even during deep undervoltage conditions.

Is the manual reset (MR) input of MAX6315US45D3+ compatible with direct switch-to-ground connection?

Yes, the MR input of MAX6315US45D3+ includes a built-in 63kΩ pull-up resistor to VCC, so it can be directly connected to a normally open momentary switch tied to GND. No external components are needed for basic manual reset functionality. For noisy environments or long PCB traces, adding a 0.1µF capacitor from MR to GND improves immunity - as documented in the Applications Information section.

What is the minimum reset timeout period specified for MAX6315US45D3+?

The MAX6315US45D3+ has a minimum reset timeout period of 140ms, as indicated by the "D3" suffix in the part number and confirmed in the Ordering Information table. This is the guaranteed minimum duration that RESET remains asserted after VCC rises above 4.50V or after MR is released. Typical values may be longer, but design-critical timing must be based on the 140ms (min) specification.