Analog Devices Inc./Maxim Integrated MAX6392KA17

Overview

MAX6392KA17 from Maxim Integrated is a dual-voltage microprocessor supervisory circuit with sequenced reset outputs for multi-rail systems. It monitors VCC (1.67V factory-fixed threshold) and RESET IN2 (adjustable down to 625mV), asserts RESET1 (push-pull, active-low) and RESET2 (open-drain, active-low) in strict power-up/power-down order, and guarantees valid reset operation down to VCC = 1.0V - used in industrial controllers requiring reliable dual-supply sequencing.

For engineers reviewing the MAX6392KA17 datasheet, MAX6392KA17 pinout, MAX6392KA17 application, or MAX6392KA17 equivalent, key selection criteria include its fixed 140ms (min) RESET1 timeout, user-adjustable or fixed RESET2 timeout via CSRT pin, manual reset (MR) input with 50µs minimum pulse width, guaranteed operation at VCC ≥ 1.0V, and immunity to short negative VCC transients.

Technical Context

The MAX6392KA17 implements two independent voltage monitoring paths: a primary comparator for VCC (threshold = 1.67V ±0.05V) driving RESET1, and a secondary comparator for RESET IN2 (625mV reference) driving RESET2. RESET2 assertion depends on either input falling below its threshold, but deassertion requires both inputs to exceed thresholds and RESET1 to deassert first.

Its timing architecture enforces strict sequencing: RESET2 always deasserts after RESET1 during power-up (tRP2 > tRP1) and asserts before RESET1 during power-down (tRD2 < tRD1). The MR input forces simultaneous assertion of both resets with 10µs skew between outputs, and internal 47kΩ pullup ensures defined MR state when unconnected.

Key Specifications

Pinout & Package

MAX6392KA17 is housed in an 8-pin SOT23 package (3.00mm × 1.75mm × 1.30mm body, 0.65mm pitch), specified for -40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX6392KA22, the MAX6392KA17 enables earlier brownout detection on low-voltage rails (1.67V vs. 2.19V), while TPS3808G125 omits critical dual-supply sequencing entirely - making MAX6392KA17 uniquely suited for multi-rail industrial and medical systems requiring strict power-order enforcement.

Availability

MAX6392KA17 is available at Aetrix Electronics and suitable for industrial PLC controllers, FPGA power sequencing, medical imaging modules, automotive ADAS ECUs, and multi-voltage monitoring systems requiring stable component supply across extended temperature ranges.

Supply support for MAX6392KA17 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 industrial, medical, communications, and consumer applications.

The MAX6391/MAX6392 product line delivers dual-voltage microprocessor supervisory circuits with sequenced reset outputs - engineered specifically for reliability-critical multi-rail systems where deterministic power-up/down ordering prevents initialization faults.

FAQ

What is the factory-set VCC reset threshold voltage for MAX6392KA17?

The MAX6392KA17 has a factory-set VCC reset threshold of 1.67V, with a tolerance of ±0.05V (minimum 1.62V, maximum 1.71V). This value is laser-trimmed during production and applies across the full -40°C to +85°C operating temperature range. The threshold is fixed and not adjustable; other variants like MAX6392KA22 offer 2.19V, but MAX6392KA17 is specifically calibrated to 1.67V for low-voltage rail supervision.

Does MAX6392KA17 support manual reset functionality, and how is it implemented?

Yes, MAX6392KA17 includes an active-low manual reset (MR) input on pin 8. It features an internal 47kΩ pullup resistor to VCC, so MR remains inactive (HIGH) when left unconnected. Asserting MR LOW forces both RESET1 (push-pull) and RESET2 (open-drain) active within 10µs, with RESET2 asserting 100ns before RESET1. After MR returns HIGH, both outputs remain asserted for their respective timeout periods (140ms min for RESET1, fixed or adjustable for RESET2).

How does the CSRT pin configure RESET2 timeout behavior in MAX6392KA17?

The CSRT pin (pin 3) determines whether RESET2 uses a fixed or adjustable timeout. When CSRT is tied directly to VCC, MAX6392KA17 enables an internal fixed-delay counter chain, yielding a guaranteed minimum 140ms RESET2 timeout. When CSRT connects to an external capacitor to ground, a 600nA current source ramps voltage across the capacitor; RESET2 deasserts when this ramp reaches 1.25V, giving tRP2 = 2.08 × 10⁶ × CCSRT seconds (e.g., 3.1ms for 1500pF).

Can MAX6392KA17 monitor a 1.0V supply rail, and what is required?

Yes, MAX6392KA17 can monitor a 1.0V rail using the RESET IN2 input (pin 1) with an external resistor divider. Since the internal reference is fixed at 625mV, a divider network (e.g., R3 = 300kΩ, R4 = 500kΩ) scales the 1.0V rail down to 625mV at RESET IN2. The device guarantees valid reset operation even when VCC drops to 1.0V, but RESET IN2 monitoring requires external resistors - no internal scaling is provided.

What is the difference between RESET1 and RESET2 output types in MAX6392KA17?

RESET1 (pin 7) is a push-pull, active-low output - it actively drives LOW and HIGH without needing an external pullup. RESET2 (pin 5) is open-drain, active-low - it only pulls LOW and requires an external pullup (via R2 pin 6) to define its HIGH voltage level. This allows RESET2 to interface with different I/O voltage domains (e.g., pulled to 1.8V while VCC = 3.3V), whereas RESET1's output swing is strictly GND-to-VCC.