Analog Devices Inc./Maxim Integrated MAX820TCPE+

Overview

MAX820TCPE+ from Maxim Integrated is a microprocessor supervisory circuit with ±2% reset and low-line threshold accuracy, 200ms power-up reset delay, and integrated watchdog timer with programmable timeout (1.6s nominal). It provides dual reset outputs (RESET/RESET), manual-reset input, chip-enable gating, and overvoltage detection - designed for critical µP power monitoring in industrial controllers and embedded systems.

For engineers reviewing the MAX820TCPE+ datasheet, MAX820TCPE+ pinout, MAX820TCPE+ application, or MAX820TCPE+ equivalent, this page delivers verified functional identity, validated pin roles, confirmed timing behavior (200ms reset delay, 70ns WDPO-to-WDO skew), exact threshold tolerances (±2%), and real-world substitution guidance for legacy supervisory IC selection.

Technical Context

The MAX820TCPE+ implements dual independent comparators (reset and low-line) with factory-trimmed 1.30V internal reference, enabling precise voltage monitoring at ±2% accuracy. Its watchdog function uses an RC-timed oscillator referenced to SWT pin capacitance, delivering 1.6s nominal timeout at VCC = 5V (k = 16.2) or 3V (k = 27).

Chip-enable gating employs a transmission gate with ≤10ns propagation delay and <15µs hold time on CE OUT during reset assertion, ensuring memory write-cycle completion. The device supports both internal threshold mode (RESET IN/INT ≤ 60mV) and external programming mode (RESET IN/INT ≥ 600mV) via resistor divider, with guaranteed RESET validity down to VCC = 1V.

Key Specifications

Pinout & Package

MAX820TCPE+ is housed in a 16-pin plastic DIP (Dual In-line Package) with 0.3-inch body width and through-hole mounting. Pin spacing is 0.1 inch, compatible with standard PCB layouts for legacy industrial control designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX792TCPE+, the MAX820TCPE+ delivers tighter threshold control essential for narrow-voltage-margin systems, while TPS3823MPDBVR sacrifices supervisory depth (no NMI, no CE gating) for footprint reduction - making MAX820TCPE+ the sole choice when ±2% accuracy and multi-function supervision are mandatory.

Availability

MAX820TCPE+ is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic instruments, telecom base station management, and automotive engine control units requiring stable component supply across extended temperature ranges (-40°C to +85°C).

Supply support for MAX820TCPE+ 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 industrial, communications, and computing applications.

The MAX820TCPE+ belongs to Maxim's microprocessor supervisory product line, engineered specifically for high-reliability power monitoring in systems where deterministic reset behavior, accurate voltage thresholds, and hardware fault detection are critical.

FAQ

What is the guaranteed reset validity range for MAX820TCPE+?

The MAX820TCPE+ guarantees RESET output validity down to VCC = 1V, meaning the reset signal remains electrically functional even as the supply voltage collapses to 1V. This is confirmed in the Absolute Maximum Ratings and Electrical Characteristics tables, where RESET output voltage is specified at VCC = 1V with ISINK = 50µA. This behavior is critical for brownout recovery in systems with wide input voltage ranges.

How does the MAX820TCPE+ differ from the MAX792TCPE+ in threshold accuracy?

The MAX820TCPE+ guarantees ±2% reset and low-line threshold accuracy in external programming mode, whereas the MAX792TCPE+ specifies ±2.5%. This tighter tolerance is explicitly stated in the Features section and Electrical Characteristics table under "Reset Threshold Voltage-External Threshold Mode (VTH)" for MAX820. No other functional differences exist between the two parts.

Can MAX820TCPE+ be used with a 3.3V microcontroller supply?

Yes, MAX820TCPE+ operates across VCC = 2.75V to 5.5V and supports 3.3V systems. Its reset thresholds (e.g., 3.06V for T suffix) and internal 1.30V reference remain accurate at 3.3V supply, and watchdog timeout scaling (k = 27) is defined for VCC = 3V. All electrical characteristics, including CE propagation delay and MR threshold, are validated across this range.

What is the purpose of the LLIN/REFOUT pin on MAX820TCPE+?

The LLIN/REFOUT pin serves dual roles: in internal threshold mode (RESET IN/INT ≤ 60mV), it outputs a buffered 1.30V reference; in external programming mode (RESET IN/INT ≥ 600mV), it becomes the low-line comparator input. This pin enables either factory-trimmed monitoring or user-defined voltage thresholds - a key differentiator confirmed in the Pin Description and Detailed Description sections.

Does MAX820TCPE+ support watchdog timeout periods other than 1.6 seconds?

Yes, MAX820TCPE+ supports adjustable watchdog timeout via an external capacitor on the SWT pin. With SWT connected to GND through a capacitor, timeout = k × C (in nF), where k = 27 for VCC = 3V and k = 16.2 for VCC = 5V. This RC-programmable feature is documented in the Watchdog Function and Selecting an Alternative Watchdog Timeout sections, enabling timeouts from ~100ms to several seconds.