Analog Devices Inc./Maxim Integrated MAX792LCPE

Overview

MAX792LCPE from Maxim Integrated is a microprocessor supervisory circuit providing reset generation, manual reset input, two-stage power-fail warning (low-line detection 120mV above reset threshold), watchdog timer with pulsed fault output (WDPO), and chip-enable gating for CMOS RAM protection. It features ±2% reset threshold accuracy in external programming mode, guaranteed RESET validity down to VCC = 1V, and 200ms reset timeout delay. Used in embedded controllers requiring reliable brownout and software fault recovery.

For engineers reviewing the MAX792LCPE datasheet, MAX792LCPE pinout, MAX792LCPE application, or MAX792LCPE equivalent, this page delivers verified functional identity, exact pin roles, confirmed reset/wdog/CE timing values, low-line comparator behavior, and real-world substitution guidance - all grounded in Maxim's official 19-0147 Rev. 4 specification.

Technical Context

The MAX792LCPE implements dual independent comparators: one for reset (threshold programmable via internal divider or external resistor network) and one for low-line warning (fixed 120mV offset above reset threshold in internal mode). Its watchdog uses an RC-timed monostable (SWT pin) with nominal 1.6s timeout at VCC = 5V, generating both advance-pulse (WDPO) and latched-fault (WDO) outputs.

Chip-enable gating operates as a transmission gate (CE IN → CE OUT) disabled during reset assertion, with 10ns max propagation delay and 15µs hold time on CE OUT when CE IN is low at reset onset - ensuring memory write-cycle completion before isolation.

Key Specifications

Pinout & Package

MAX792LCPE is housed in a 16-pin plastic DIP (Dual In-line Package) with 0.3-inch body width and through-hole mounting.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX692ACPE+ and TPS3823MP, the MAX792LCPE uniquely integrates low-line warning with precise 120mV offset, pulsed watchdog output for fault discrimination, and hardware-enforced chip-enable gating - making it irreplaceable in systems requiring coordinated memory protection and multi-level power-fail response.

Availability

MAX792LCPE is available at Aetrix Electronics and suitable for industrial PLCs, medical diagnostic instruments, telecom remote terminal units, and automotive body control modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX792LCPE 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, and communications applications.

The MAX792 family was engineered specifically for microprocessor-based systems needing comprehensive power supervision - combining reset, watchdog, low-line warning, and memory protection in a single 16-pin IC.

FAQ

What is the exact reset threshold voltage for MAX792LCPE?

The MAX792LCPE has a nominal reset threshold voltage of 4.62V, specified with ±2% accuracy in external programming mode per Maxim's 19-0147 Rev. 4 datasheet. This value is fixed for the 'L' suffix variant and applies across the 0°C to +70°C operating range. Internal mode operation maintains this same threshold, derived from the factory-trimmed voltage divider.

How does the low-line warning function in MAX792LCPE differ from standard reset detection?

The MAX792LCPE's low-line warning (LOW LINE pin) asserts 120mV above the reset threshold - for example, at 4.74V when reset triggers at 4.62V. This provides a deterministic early warning window, allowing firmware to execute graceful shutdown or data save routines before the hard reset occurs. Unlike simple reset monitoring, this two-stage detection is implemented with dedicated comparator hysteresis and independent output timing.

Can MAX792LCPE be used with a 3.3V microprocessor supply?

Yes, the MAX792LCPE supports VCC from 2.75V to 5.5V, making it compatible with 3.3V systems. When powered from 3.3V, its reset threshold remains 4.62V - so it must monitor a higher-voltage rail (e.g., 5V auxiliary supply) or use external resistor programming to scale thresholds downward. The device itself cannot supervise a 3.3V rail with 4.62V threshold; alternative suffixes (e.g., MAX792TCPE for 3.06V) or external mode configuration are required.

What is the purpose of the WDPO pin on MAX792LCPE, and how is it timed relative to WDO?

The WDPO (Watchdog Pulse Output) pin on MAX792LCPE delivers a 500µs to 6ms active-low pulse immediately before WDO assertion, with a fixed 70ns lead time. This allows external logic (e.g., a D flip-flop) to detect the first watchdog timeout and prepare for potential second-fault latching. WDPO is not latched - it pulses once per timeout event - whereas WDO remains asserted until the next WDI transition, enabling hardware-level fault escalation.

Does MAX792LCPE provide memory write-cycle completion support during power-down?

Yes, the MAX792LCPE guarantees memory write-cycle completion via its chip-enable gating architecture. When reset is asserted while CE IN is low, CE OUT remains low for 15µs - sufficient to complete typical SRAM or EEPROM write cycles. This behavior is explicitly characterized in the datasheet and eliminates need for external hold-time circuitry, directly protecting nonvolatile memory integrity during brownout events.