Analog Devices Inc./Maxim Integrated MAX6312UK29D3+T

Overview

MAX6312UK29D3+T from Maxim Integrated is a precision 5-pin SOT23 programmable supervisory IC that monitors VCC (factory-set 2.9V reset threshold), an external undervoltage input (RST IN_), and a manual-reset input (MR) to assert an active-high push/pull RESET output. It guarantees valid reset assertion down to VCC = 1.0V, features 140ms minimum reset timeout, consumes only 8µA supply current, and is immune to fast VCC transients-ideal for multivoltage embedded control systems requiring reliable power-on and brownout protection.

For engineers reviewing the MAX6312UK29D3+T datasheet, MAX6312UK29D3+T pinout, MAX6312UK29D3+T application, or MAX6312UK29D3+T equivalent, this page delivers verified technical context, factory-trimmed threshold accuracy (±2.5% over –40°C to +85°C), MR input logic levels, guaranteed reset timeout stability, and real-world design implications for portable and industrial microprocessor supervision.

Technical Context

The MAX6312UK29D3+T implements a dual-monitoring architecture: its internal factory-trimmed voltage divider sets the primary VCC reset threshold at 2.9V (±2.5% over temperature), while the RST IN_ input compares external voltages against a precise 1.23V internal reference. The MR input includes a 63.5kΩ internal pull-up and supports TTL/CMOS logic drive with 1.5µs minimum pulse width.

It uses a dedicated internal timer to enforce a fixed 140ms (min) reset timeout after all monitored supplies return to regulation, and asserts RESET high (push/pull) with VOH ≥ 0.8 × VCC (at ISOURCE = 10µA) and VOL ≤ 0.3V (at ISINK = 500µA). Reset remains active during VCC brownouts below 1.0V, ensuring deterministic µP initialization.

Key Specifications

Pinout & Package

MAX6312UK29D3+T is housed in a RoHS-compliant, lead-free 5-pin SOT23 package (outline U5+1, land pattern 90-0174), optimized for space-constrained PCB layouts and automated assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6312UK29D3-T, the +T variant ensures RoHS compliance without performance trade-offs; versus TPS3808G33DBVR, MAX6312UK29D3+T provides essential dual-input supervision and manual reset at higher IQ, making it superior for complex multivoltage systems requiring field serviceability and fault resilience.

Availability

MAX6312UK29D3+T is available at Aetrix Electronics and suitable for industrial PLCs, medical patient monitors, automotive body control modules, smart energy meters, and portable instrumentation requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MAX6312UK29D3+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 and mixed-signal ICs for demanding industrial, medical, and automotive applications, emphasizing reliability, low power, and integration.

The MAX6305–MAX6313 family was engineered specifically for multivoltage microprocessor supervision in space- and power-constrained systems, delivering factory-trimmed thresholds, transient immunity, and flexible reset timing without external components.

FAQ

What is the exact factory-set VCC reset threshold for MAX6312UK29D3+T?

The MAX6312UK29D3+T has a nominal VCC reset threshold of 2.90V, with tolerance of ±2.5% over the full operating temperature range (–40°C to +85°C). This value is factory-trimmed using an internal resistor divider and corresponds to the "29" in the part number per Table 1 of the datasheet. The actual measured threshold for a given unit falls between 2.828V and 2.972V at +25°C.

Does MAX6312UK29D3+T support monitoring of a second voltage rail besides VCC?

Yes, MAX6312UK29D3+T supports monitoring of a second voltage rail via its RST IN_ pin, which compares an externally divided voltage against a precise 1.23V internal reference. This allows supervision of rails such as 5V, 12V, or 24V using two external resistors. Unlike the VCC monitor, RST IN_ is fully adjustable and independent of the 2.9V factory setting.

What is the function and electrical behavior of the MR pin on MAX6312UK29D3+T?

The MR (Manual Reset) pin on MAX6312UK29D3+T is an active-low input with an internal 63.5kΩ pull-up resistor. Driving MR low for ≥1.5µs forces a full reset cycle: RESET goes high and remains asserted for the full 140ms timeout period, even after MR returns high. The pin accepts TTL/CMOS logic levels and must be referenced to the same VCC supply to avoid violating absolute maximum ratings.

Can MAX6312UK29D3+T operate reliably during severe VCC brownout conditions?

Yes, MAX6312UK29D3+T guarantees valid RESET output down to VCC = 1.0V, meaning it continues asserting the active-high reset signal throughout deep brownout events. Below 1.0V, reset behavior is not specified. This ensures microprocessors remain held in reset until supply collapse is complete, preventing erratic operation or memory corruption.

What are the key timing parameters associated with the reset timeout function of MAX6312UK29D3+T?

MAX6312UK29D3+T provides a factory-programmed minimum reset timeout of 140ms (D3 variant). The actual timeout varies slightly with temperature and supply voltage but remains tightly controlled - typical variation is ±1% over –40°C to +85°C. This interval begins when all monitored supplies (VCC and RST IN_) exceed their respective thresholds and ends with RESET deassertion, ensuring µP initialization completes safely.