Analog Devices Inc./Maxim Integrated MAX709MCPA

Overview

MAX709MCPA from Maxim Integrated is a precision power-supply monitor IC with active-low reset output, designed for +5V/+3.3V/+3V systems. It asserts RESET when VCC falls below 4.40V (±0.15V), holds reset for ≥140ms after VCC recovers, and operates down to VCC = 1V. Used in microprocessor-based embedded controllers to prevent erratic startup or brownout operation.

For engineers reviewing the MAX709MCPA datasheet, MAX709MCPA pinout, MAX709MCPA application, or MAX709MCPA equivalent, key selection criteria include reset threshold accuracy (4.40V), guaranteed minimum reset timeout (140ms), low quiescent current (65µA), immunity to short VCC transients, and compatibility with DIP-8 packaging for through-hole prototyping and industrial control boards.

Technical Context

The MAX709MCPA integrates a precision voltage comparator, internal timing capacitor, and open-drain RESET driver - eliminating external components. Its reset threshold is factory-trimmed to 4.40V with ±3.4% tolerance over −40°C to +85°C, and its 140ms power-on delay is temperature-stable across the full operating range.

It features dual-stage immunity: first, a built-in hysteresis prevents chatter during slow VCC ramps; second, transient rejection logic ignores negative VCC glitches ≤40µs when overdrive is ≤100mV below threshold - critical for noisy industrial power rails.

Key Specifications

Pinout & Package

MAX709MCPA is supplied in an 8-pin plastic DIP package (0.300" wide), compatible with standard through-hole PCB assembly and socketing for test/development.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar power-supply monitor applications.

Compared with MAX706MCPA, MAX709MCPA offers simpler BOM count and lower cost by omitting MR functionality; compared with TL7705ACPE4, it delivers tighter threshold tolerance (±3.4% vs ±4.4%), lower quiescent current, and documented glitch rejection - making it preferable for noise-prone industrial and automotive applications.

Availability

MAX709MCPA is available at Aetrix Electronics and suitable for industrial PLC controllers, medical diagnostic devices, automotive body control modules, point-of-sale terminals, and embedded instrumentation requiring stable component supply and long-term obsolescence management.

Supply support for MAX709MCPA 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 MAX709 series belongs to Maxim's µP supervisory circuit product line, engineered specifically to replace discrete reset solutions in cost-sensitive, space-constrained microprocessor systems operating at +5V, +3.3V, or +3V rails.

FAQ

What is the exact reset threshold voltage of the MAX709MCPA?

The MAX709MCPA has a nominal reset threshold voltage of 4.40V, with a guaranteed range of 4.25V to 4.50V over the full operating temperature range (−40°C to +85°C). This value is factory-trimmed and specified in the Electrical Characteristics table of the official MAX709 datasheet. The 'M' suffix in MAX709MCPA explicitly denotes the 4.40V variant.

Does the MAX709MCPA require external components to function?

No, the MAX709MCPA requires no external resistors, capacitors, or diodes to perform basic power-supply monitoring and reset generation. A 0.1µF ceramic bypass capacitor on V_CC (pin 2) is recommended for noise immunity but is not strictly required for functional operation. The internal timing capacitor provides the 140ms reset timeout, eliminating external RC networks.

What is the operating temperature range for the MAX709MCPA?

The MAX709MCPA is rated for operation from −40°C to +85°C. This is indicated by the 'E' prefix in the full ordering code (e.g., MAX709ECPA), but the 'M' suffix in MAX709MCPA refers only to the 4.40V threshold. The 'CPA' package suffix confirms the commercial-grade temperature range (0°C to +70°C); however, per Maxim's official ordering information, MAX709_CPA is 0°C to +70°C, while MAX709_EPA is −40°C to +85°C - thus MAX709MCPA is the 0°C to +70°C version.

Can the MAX709MCPA drive a microprocessor reset pin directly?

Yes, the MAX709MCPA can drive most microprocessor reset pins directly using its open-drain RESET output (pin 7). An external pull-up resistor (typically 10kΩ to V_CC) is required to establish the inactive logic-high state. The output sinks up to 20mA, which exceeds the input leakage and capacitance requirements of common µPs like ARM Cortex-M or PIC families.

How does the MAX709MCPA handle short voltage transients on the V_CC rail?

The MAX709MCPA is specifically designed to reject short negative-going V_CC transients: it will not assert RESET for glitches ≤40µs duration when the overdrive (V_TH − V_CC) is ≤100mV. This behavior is characterized in Figure 1 of the MAX709 datasheet and makes the MAX709MCPA robust in electrically noisy environments such as motor controls or relay-driven systems.