Analog Devices Inc./Maxim Integrated MAX6312UK46D3

Overview

MAX6312UK46D3 from Maxim Integrated is a 5-pin SOT23 programmable supervisory circuit that monitors VCC and an external undervoltage input (RST IN), asserts active-high push/pull RESET when either falls below its threshold, and features factory-set 4.63V VCC reset threshold with ±2.5% tolerance over -40°C to +85°C and 140ms minimum reset timeout. It draws only 8µA supply current and guarantees valid RESET output down to VCC = 1.0V, making it suitable for multivoltage embedded control systems requiring reliable brownout detection.

For engineers reviewing the MAX6312UK46D3 datasheet, MAX6312UK46D3 pinout, MAX6312UK46D3 application, or MAX6312UK46D3 equivalent, this page delivers verified technical context, exact pin functions, real-world timing behavior under temperature variation, manual-reset interface requirements, and validated alternative options for dual-supply monitoring in portable and industrial microprocessor systems.

Technical Context

The MAX6312UK46D3 implements a dual-input supervision architecture: one internal factory-trimmed voltage divider sets the primary VCC reset threshold at 4.63V (nominal), while a second adjustable comparator accepts an external RST IN signal referenced to a 1.23V internal bandgap. Its active-high push/pull RESET output sources ≥0.8×VCC at 10µA and sinks ≤0.3V at 500µA, ensuring compatibility with CMOS and TTL logic families across 1.0V–5.5V VCC range.

It incorporates transient immunity circuitry that ignores fast VCC dips - e.g., a 100mV overdrive below threshold allows up to ~200µs negative transients without false reset - and includes an internal 63.5kΩ pull-up on MR, enabling direct connection of a momentary switch to GND without external components. The device operates over -40°C to +85°C and maintains ±2.5% reset threshold accuracy across that full range.

Key Specifications

Pinout & Package

MAX6312UK46D3 is housed in a 5-pin SOT23 package (outline U5+1, land pattern 90-0174), measuring 2.9mm × 1.6mm × 1.1mm, with gull-wing leads and RoHS-compliant lead-free option available (+T suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-input supervisory applications.

Compared with MAX6312EUK46D3, the MAX6312UK46D3 offers identical electrical performance but narrower temperature rating, while TPS3808G33DBVR reduces functionality to meet ultra-low-power needs at the expense of supervision flexibility - making MAX6312UK46D3 optimal for commercial-grade multivoltage systems requiring manual reset and auxiliary rail monitoring.

Availability

MAX6312UK46D3 is available at Aetrix Electronics and suitable for industrial PLCs, portable medical devices, automotive body electronics, and smart energy metering applications requiring stable component supply, long-term lifecycle support, and guaranteed factory programming.

Supply support for MAX6312UK46D3 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 demanding industrial, medical, and communications applications, with emphasis on reliability, low power, and integration.

The MAX6305–MAX6313 family was engineered specifically for multivoltage microprocessor supervision in space-constrained, battery-sensitive systems - delivering factory-trimmed accuracy, transient immunity, and dual-input flexibility in SOT23 packaging.

FAQ

What is the exact factory-set reset threshold voltage for MAX6312UK46D3?

The MAX6312UK46D3 has a nominal VCC reset threshold of 4.63V, with ±2.5% tolerance over the full -40°C to +85°C operating temperature range. This value is factory-trimmed using an internal resistor divider and corresponds to the "46" in the part number per Table 1 of the datasheet. At +25°C, the typical threshold is 4.63V, with min/max bounds of 4.514V and 4.746V.

Does MAX6312UK46D3 support manual reset functionality, and how is it implemented?

Yes, MAX6312UK46D3 includes a dedicated MR (manual reset) input on pin 4. It is active-low with an internal 63.5kΩ pull-up resistor, allowing direct connection of a momentary switch to GND. A logic-low pulse ≥1.5µs asserts RESET for the full 140ms timeout period. No external pull-up or debounce components are required, simplifying board layout and reducing BOM count.

Can MAX6312UK46D3 monitor a 3.3V supply in addition to its primary 5V VCC rail?

Yes, MAX6312UK46D3 can monitor a 3.3V supply using its RST IN pin (pin 3). By connecting a resistor divider from the 3.3V rail to RST IN and GND, the input is compared to the internal 1.23V reference. For example, a 1.6MΩ/1MΩ divider yields a 3.3V threshold. This enables coordinated reset assertion if either the 5V VCC (4.63V) or 3.3V auxiliary rail fails.

What is the guaranteed operating VCC range for MAX6312UK46D3, and why does it matter?

MAX6312UK46D3 operates from VCC = 1.0V to 5.5V and guarantees valid active-high RESET output down to VCC = 1.0V. This is critical for brownout resilience: even as the main supply collapses, the IC continues asserting RESET until VCC drops below 1.0V, preventing the microprocessor from executing corrupted code during power-down sequences in battery-powered equipment.

How does the reset timeout period of MAX6312UK46D3 compare to other variants in the MAX6312 family?

MAX6312UK46D3 uses the D3 timeout index, providing a minimum reset pulse width of 140ms. Other variants include D1 (1ms), D2 (20ms), and D4 (1120ms). The 140ms value balances robust power-up stabilization against excessive boot delays - sufficient for most DC-DC converters and microcontrollers while avoiding unnecessary wait times in responsive embedded systems.