Analog Devices Inc./Maxim Integrated MAX6315US28D1-T

Overview

The MAX6315US28D1-T from Analog Devices 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 2.83V or upon manual reset assertion. It provides a factory-trimmed 1ms minimum reset timeout period, consumes only 5μA typical supply current at 5.5V, and operates across -40°C to +125°C. It is used in portable battery-powered equipment to ensure reliable μP initialization during power-up and brownout.

For engineers reviewing the MAX6315US28D1-T datasheet, MAX6315US28D1-T pinout, MAX6315US28D1-T application, or MAX6315US28D1-T equivalent, key selection criteria include its 2.83V reset threshold tolerance (±3.5% over temperature), SOT23-4 open-drain output capable of pullup beyond VCC, immunity to sub-100ns MR glitches, and guaranteed operation down to VCC = 1.0V.

Technical Context

The MAX6315US28D1-T implements a precision voltage-monitoring comparator with laser-trimmed internal resistive divider setting nominal VTH = 2.83V, and a monolithic timer circuit generating a fixed 1ms minimum reset timeout after VCC recovery or MR release. Its reset assertion logic is purely analog-comparator driven with no digital state machine.

It features an internal 63kΩ MR pullup resistor and guarantees RESET sink capability of 3.2mA at VCC > 4.25V while maintaining VOL ≤ 0.4V. The open-drain output allows level-shifting across supplies up to +6V independent of VCC, enabling use in mixed-voltage systems where reset signaling must cross rail boundaries.

Key Specifications

Pinout & Package

MAX6315US28D1-T is housed in a RoHS-compliant 4-pin SOT23 package (outline 21-0052), with 1.3mm × 2.9mm footprint and 0.95mm height, optimized for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX811SEUS+T and TPS3808G125DBVR, the MAX6315US28D1-T delivers the shortest standard timeout (1ms) and tightest factory-trimmed 2.83V threshold, making it optimal for fast-recovery embedded systems where minimal reset duration and exact brownout detection are prioritized over configurability or lowest quiescent current.

Availability

MAX6315US28D1-T is available at Aetrix Electronics and suitable for battery-powered instrumentation, industrial PLC controllers, automotive body control modules, and medical point-of-care devices requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX6315US28D1-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

Analog Devices is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.

The MAX6315 series belongs to Analog Devices' precision supervisory IC product line, engineered specifically for deterministic power-on reset, brownout protection, and manual reset integration in resource-constrained embedded systems.

FAQ

What is the exact reset threshold voltage of the MAX6315US28D1-T?

The MAX6315US28D1-T has a factory-trimmed nominal reset threshold voltage of 2.83V, with tolerance of ±3.5% over the full operating temperature range (-40°C to +125°C). This value is laser-trimmed during manufacturing and does not require external calibration. The MAX6315US28D1-T maintains this accuracy without user adjustment, ensuring consistent brownout detection across environmental conditions.

Does the MAX6315US28D1-T support operation below 2.0V VCC?

Yes, the MAX6315US28D1-T is fully specified to operate down to VCC = 1.0V, and its RESET output remains functional and guaranteed to sink current even at this level. At VCC = 1.0V, the device still asserts RESET when voltage falls below 2.83V (i.e., during initial power-up ramp), and maintains reset hold for the full 1ms timeout after recovery. This enables use in ultra-low-voltage brownout scenarios where other supervisors fail.

Can the RESET output of the MAX6315US28D1-T be pulled up to a voltage higher than VCC?

Yes, the MAX6315US28D1-T features an open-drain RESET output rated for voltages up to +6.0V, allowing it to be pulled up to a supply rail higher than VCC (e.g., pulling RESET to 5V while monitoring a 3.3V rail). This capability eliminates the need for external level-shifting circuitry and supports interoperability between different logic domains in mixed-supply systems.

What is the minimum reset timeout period for the MAX6315US28D1-T?

The MAX6315US28D1-T provides a minimum reset timeout period of 1ms, guaranteed over temperature (-40°C to +125°C). This value is internally programmed and fixed for the D1 variant; it ensures sufficient hold time for microcontrollers to complete internal power-on reset sequencing without unnecessary delay. The actual timeout may extend slightly due to process variation but will never fall below 1ms.

Is external debounce required for the manual reset (MR) input on the MAX6315US28D1-T?

No, external debounce is not required for the MR input of the MAX6315US28D1-T. The device includes built-in 100ns glitch rejection and an internal 63kΩ pullup resistor, enabling direct connection of a momentary switch from MR to GND. In electrically noisy environments or with long PCB traces, adding a 0.1μF capacitor from MR to GND is optional for enhanced immunity but not mandatory for basic functionality.