Analog Devices Inc./Maxim Integrated MAX6307UK28D4-T

Overview

The MAX6307UK28D4-T from Maxim Integrated is a 5-pin SOT23 programmable supervisory IC that monitors VCC (factory-set 2.8V reset threshold), an adjustable undervoltage input (RST IN), and an adjustable overvoltage input (OVRST IN) to assert a push/pull active-low RESET output. It features 1120ms minimum reset timeout, 8µA supply current, and guaranteed RESET validity down to VCC = 1V. It is used in multivoltage embedded systems requiring robust brownout and transient immunity.

For engineers reviewing the MAX6307UK28D4-T datasheet, MAX6307UK28D4-T pinout, MAX6307UK28D4-T application, or MAX6307UK28D4-T equivalent, key selection criteria include its dual external reset inputs (RST IN/OVRST IN), factory-trimmed 2.8V VCC threshold with ±2.5% tolerance over temperature, 1120ms timeout, SOT23-5 package compatibility, and immunity to fast VCC transients up to 100V/µs.

Technical Context

The MAX6307UK28D4-T implements a triple-monitor architecture: internal factory-trimmed resistor divider for VCC supervision at 2.8V nominal, precision 1.23V reference-based comparator for RST IN (undervoltage), and same-reference comparator for OVRST IN (overvoltage). All three inputs drive a shared reset generator with a fixed 1120ms timeout period after recovery.

Its push/pull RESET output guarantees VOL ≤ 0.3V at ISINK = 500µA and VOH ≥ 0.8 × VCC at ISOURCE = 150µA, enabling direct interface with 3.3V/5V µP reset pins without external pull-up. The device operates from VCC = (VTH + 2.5%) to +5.5V - i.e., 2.87V to 5.5V - and remains functional across 0°C to +70°C.

Key Specifications

Pinout & Package

MAX6307UK28D4-T is housed in a RoHS-compliant 5-pin SOT23 package (outline 21-0057, land pattern 90-0174), measuring 2.9mm × 1.6mm × 1.1mm, suitable for high-density PCB layouts in space-constrained portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6307UK28D4-T, the MAX6307UK28D3-T offers identical supervision capability with reduced timeout for speed-critical systems, while the TPS3808G33DBVR trades triple monitoring and push/pull drive for ultra-low current and lower cost in simpler single-supply designs.

Availability

MAX6307UK28D4-T is available at Aetrix Electronics and suitable for industrial PLC power monitoring, medical portable diagnostic devices, automotive body control modules, and telecom remote radio units requiring stable component supply across extended temperature and lifecycle requirements.

Supply support for MAX6307UK28D4-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) is a U.S.-based semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, communications, and computing markets.

The MAX6305–MAX6313 family was designed specifically for multivoltage embedded systems needing simultaneous monitoring of primary and auxiliary rails with immunity to real-world power transients and minimal external components.

FAQ

What is the exact factory-set VCC reset threshold for MAX6307UK28D4-T?

The MAX6307UK28D4-T has a factory-trimmed VCC reset threshold of 2.8V nominal, with tolerance of ±2.5% over the operating temperature range of 0°C to +70°C. This value is confirmed in Table 1 of the datasheet and corresponds to the "28" in the part number (2.8V). The actual threshold is set via an internal precision resistor divider and does not require external calibration.

Does MAX6307UK28D4-T support monitoring of both undervoltage and overvoltage conditions on external supplies?

Yes, MAX6307UK28D4-T supports both functions via dedicated pins: RST IN serves as an undervoltage monitor (asserts reset when input falls below 1.23V reference), and OVRST IN serves as an overvoltage monitor (asserts reset when input exceeds 1.23V reference). Each uses the same internal 1.23V bandgap reference and can be configured with external resistor dividers for custom thresholds.

What is the minimum VCC voltage required for MAX6307UK28D4-T to operate correctly?

The MAX6307UK28D4-T requires VCC ≥ (VTH + 2.5%), i.e., ≥ 2.87V, to guarantee proper operation and reset assertion. Below this, the internal voltage divider cannot reliably compare against the 2.8V threshold. However, the RESET output remains valid down to VCC = 1V - meaning it continues to drive logic-low correctly even during deep brownout, as verified in the Electrical Characteristics table.

Can MAX6307UK28D4-T replace a standard single-supply reset IC in a design?

Yes, MAX6307UK28D4-T can replace single-supply supervisors such as the MAX6305 series, provided the design benefits from its additional RST IN and OVRST IN inputs. Its pin-compatible SOT23-5 footprint and identical VCC/RESET/GND connections allow drop-in substitution in many cases - though unused RST IN and OVRST IN pins must be tied appropriately (to VCC and GND respectively) to avoid floating inputs.

What is the guaranteed reset timeout period for MAX6307UK28D4-T, and how is it implemented?

The MAX6307UK28D4-T guarantees a minimum reset timeout period of 1120ms after all monitored supplies return above their thresholds. This is a factory-programmed, temperature-stable delay generated by an internal RC oscillator - no external capacitor is needed. The "D4" in the part number explicitly denotes this 1120ms option, and the timeout remains within ±40% over temperature per the datasheet's tRP specification.