Analog Devices Inc./Maxim Integrated MAX6306UK44D2+T

Overview

MAX6306UK44D2+T from Maxim Integrated is a 5-pin SOT23 programmable supervisory IC that monitors VCC supply voltage and provides manual reset capability. It features a factory-programmed 4.38V ±1.5% reset threshold, 20ms minimum reset timeout, open-drain active-low RESET output, and guaranteed reset assertion down to VCC = 1V. It is used in multivoltage embedded systems requiring reliable power-on and brownout reset generation.

For engineers reviewing the MAX6306UK44D2+T datasheet, MAX6306UK44D2+T pinout, MAX6306UK44D2+T application, or MAX6306UK44D2+T equivalent, key selection criteria include its 4.38V VCC reset threshold tolerance, 20ms timeout stability over temperature, MR input compatibility with TTL/CMOS logic, immunity to fast VCC transients, and guaranteed reset validity at low VCC (1V).

Technical Context

The MAX6306UK44D2+T uses an internal factory-trimmed resistor divider to monitor VCC against a precision 1.23V reference, enabling accurate 4.38V threshold detection. Its reset generator includes a temperature-stable RC timer for the 20ms minimum timeout period and asserts RESET low when VCC falls below threshold or MR is pulled low.

This device integrates a 63.5kΩ internal pull-up on the MR pin, supports undervoltage monitoring only on VCC (no external RST IN_ or OVRST IN inputs), and guarantees valid RESET output down to VCC = 1V with 0.3V VOL at ISINK = 50µA - critical for low-voltage brownout detection in portable systems.

Key Specifications

Pinout & Package

MAX6306UK44D2+T is housed in a lead-free 5-pin SOT23 package (outline U5+1, land pattern 90-0174), optimized for space-constrained PCB layouts and reflow-compatible assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voltage supervision applications.

Compared with MAX6306UK44D2+T, the MAX6306UK44D3+T offers identical supervision accuracy and MR support but extends reset hold time for slower power rails, while TPS3808G33DBVR trades threshold flexibility and MR capability for lower unit cost in fixed 3.3V use cases.

Availability

MAX6306UK44D2+T is available at Aetrix Electronics and suitable for portable computers, embedded control systems, and intelligent instruments requiring stable component supply with guaranteed long-term availability.

Supply support for MAX6306UK44D2+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 power management, sensing, and interface applications.

The MAX6305–MAX6313 family delivers compact, low-power supervisory solutions for multivoltage systems, emphasizing factory-programmed accuracy, transient immunity, and minimal external component count.

FAQ

What is the exact factory-programmed reset threshold voltage for MAX6306UK44D2+T?

The MAX6306UK44D2+T has a factory-programmed VCC reset threshold of 4.38V, with ±1.5% tolerance at +25°C and ±2.5% over the full 0°C to +70°C operating range. This value is derived from Table 1 in the datasheet, where "44" corresponds to 4.38V nominal, and is implemented via internal laser-trimmed resistors. The MAX6306UK44D2+T uses this precise threshold to detect brownout on 4.4V or 5V rails.

Does MAX6306UK44D2+T support external voltage monitoring inputs like RST IN_ or OVRST IN?

No, the MAX6306UK44D2+T does not support external adjustable reset inputs. Per the datasheet selector table and pin description, it monitors only VCC through its internal factory-trimmed divider and includes a manual reset (MR) input - but no RST IN_ or OVRST IN pins. Those functions are present only on variants like MAX6307/MAX6313. The MAX6306UK44D2+T is strictly a single-rail VCC supervisor with MR capability.

What is the guaranteed minimum reset timeout period for MAX6306UK44D2+T?

The MAX6306UK44D2+T guarantees a minimum reset timeout period of 20ms, corresponding to the "D2" suffix in its part number. Electrical Characteristics confirm tRP = 20ms (min) at TA = +25°C, with 28ms (typ) and 40ms (max). This timeout is temperature-stable, varying less than ±1% across 0°C to +70°C, ensuring consistent reset hold time for microprocessor initialization in the MAX6306UK44D2+T.

Can MAX6306UK44D2+T operate reliably when VCC drops below 2.0V?

Yes, the MAX6306UK44D2+T guarantees valid RESET assertion down to VCC = 1.0V, as specified in the Electrical Characteristics table (VOL = 0.3V at ISINK = 50µA, VCC > 1.0V). Its internal circuitry remains functional and drives RESET low during deep brownout, making it suitable for low-voltage fault detection. However, below 1.0V, reset behavior is not guaranteed - a key design boundary for the MAX6306UK44D2+T.

Is the MR (manual reset) input of MAX6306UK44D2+T internally pulled up, and what is its resistance value?

Yes, the MR input of MAX6306UK44D2+T includes an internal pull-up resistor with a nominal value of 63.5kΩ, ranging from 32kΩ to 100kΩ across process and temperature. This allows the pin to be left floating (unconnected) when manual reset is unused, simplifying design. When asserted, MR requires a logic-low signal ≤0.8V, and the MAX6306UK44D2+T holds RESET active for the full 20ms timeout after MR returns high.