Analog Devices Inc./Maxim Integrated MAX6392KA26+

Overview

MAX6392KA26+ from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with sequenced reset outputs, monitoring VCC (2.63V factory-fixed threshold) and an adjustable secondary supply (RESET IN2), delivering time-sequenced active-low RESET1 (push-pull) and RESET2 (open-drain) for multi-rail power-up/down control in industrial controllers and servers.

For engineers reviewing the MAX6392KA26+ datasheet, MAX6392KA26+ pinout, MAX6392KA26+ application, or MAX6392KA26+ equivalent, this device supports precise voltage sequencing, manual reset assertion, guaranteed reset validity down to VCC = 1V, and configurable RESET2 timeout via CSRT capacitor or fixed 140ms delay - critical for reliable boot-order management in dual-supply embedded systems.

Technical Context

The MAX6392KA26+ implements two independent voltage comparators: one monitors VCC against a factory-trimmed 2.63V threshold (±70mV), while the second compares RESET IN2 against a fixed 625mV internal reference. RESET1 is push-pull and asserts only on VCC undervoltage; RESET2 is open-drain and asserts if either VCC or RESET IN2 falls below their thresholds.

Sequencing logic ensures RESET2 deasserts after RESET1 during power-up (tRP2 ≥ tRP1) and asserts before RESET1 during power-down (tRD2 < tRD1). A dedicated MR input (active-low, 47kΩ internal pullup) forces both resets synchronously, with tMR1 = 10µs and tMR2 = 100ns delays - enabling deterministic system-level reset initiation.

Key Specifications

Pinout & Package

MAX6392KA26+ is housed in an 8-pin SOT23 package (JEDEC MO-178 compliant, 1.95mm × 2.80mm footprint, 1.30mm height), optimized for space-constrained PCB layouts in industrial and computing applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6392KA26+, MAX6392KA29+ offers identical functionality at a higher threshold for 3.0V rails, while TPS3808G33DBVR reduces complexity but sacrifices dual-monitoring capability and reset sequencing - making MAX6392KA26+ the only option supporting true multi-rail coordination with manual reset.

Availability

MAX6392KA26+ is available at Aetrix Electronics and suitable for industrial controllers, server motherboards, medical diagnostic devices, and network equipment requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.

Supply support for MAX6392KA26+ 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, mixed-signal, and power management ICs for demanding industrial, computing, and communications applications.

The MAX6391/MAX6392 product line delivers sequenced dual-supply supervision for complex multi-voltage systems - specifically engineered to replace discrete reset solutions in servers, PLCs, and high-reliability embedded platforms.

FAQ

What is the factory-trimmed VCC reset threshold voltage for MAX6392KA26+?

The MAX6392KA26+ has a factory-trimmed VCC reset threshold of 2.63V, with a tolerance of ±70mV (min 2.55V, max 2.70V) across the -40°C to +85°C temperature range. This value is laser-trimmed during production and applies exclusively to the MAX6392KA26+ variant - other suffixes (e.g., KA29+, KA31+) have different thresholds. The 2.63V threshold makes MAX6392KA26+ ideal for monitoring 2.5V or 2.8V supply rails in industrial and computing systems.

Does MAX6392KA26+ support manual reset, and how is it implemented?

Yes, MAX6392KA26+ includes an active-low manual reset input (MR) on pin 8, with an internal 47kΩ pullup resistor to VCC. Pulling MR low asserts both RESET1 (push-pull) and RESET2 (open-drain) simultaneously. RESET1 remains asserted for its full 140ms timeout after MR returns high, while RESET2 follows its configured timeout (140ms min or capacitor-adjustable). The MR pin requires a minimum 50µs pulse width and rejects glitches shorter than 100ns - ensuring robustness against noise in MAX6392KA26+ deployments.

How is the RESET2 timeout period configured on MAX6392KA26+?

The RESET2 timeout on MAX6392KA26+ is configured via the CSRT pin (pin 3): connecting CSRT to VCC selects a fixed 140ms minimum delay, while connecting CSRT to a capacitor-to-ground enables user-adjustable timing using tRP2 = 2.08 × 10⁶ × CCSRT (e.g., 1500pF yields ~3.1ms). Unlike RESET1, which is fixed, RESET2's flexibility allows fine-grained control over slave-supply stabilization windows - a key differentiator of MAX6392KA26+ versus single-output supervisors.

Can MAX6392KA26+ monitor a 1.2V supply rail, and if so, how?

Yes, MAX6392KA26+ can monitor a 1.2V rail using the RESET IN2 input (pin 1) with an external resistive divider. Since the internal reference is fixed at 625mV, a divider with R3 = 470kΩ and R4 = 500kΩ yields VRST ≈ 1.2V. The MAX6392KA26+'s 50nA input leakage ensures minimal loading, and its guaranteed operation down to VCC = 1.0V means the device remains functional even as the monitored 1.2V rail sags - a capability confirmed in the MAX6392KA26+ datasheet's Electrical Characteristics table.

What is the maximum supply voltage and operating temperature range for MAX6392KA26+?

MAX6392KA26+ operates from VCC = 1.2V to 5.5V and is specified over the extended industrial temperature range of -40°C to +85°C. Absolute maximum ratings allow VCC up to +6.0V, but functional operation is guaranteed only within the 1.2V–5.5V range. The -40°C to +85°C specification covers all electrical parameters in the datasheet, including reset thresholds, timeouts, and supply current (15µA typical), making MAX6392KA26+ suitable for harsh-environment deployments like factory automation and outdoor networking gear.