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 1.0V supply-enabling reliable microprocessor supervision in industrial control and embedded instrumentation.

For engineers reviewing the MAX709MCPA+ datasheet, MAX709MCPA+ pinout, MAX709MCPA+ application, or MAX709MCPA+ equivalent, key selection criteria include reset threshold accuracy (4.40V nominal), guaranteed reset assertion at VCC ≥1V, 65µA supply current (TA = TMIN to TMAX), immunity to ≤40µs/100mV negative VCC transients, and compatibility with 8-pin plastic DIP packaging.

Technical Context

The MAX709MCPA+ integrates a precision voltage comparator with hysteresis, internal timing capacitor, and open-drain RESET driver. Its reset threshold is factory-trimmed to 4.40V (MAX709M suffix) with ±0.15V tolerance over –40°C to +85°C, and features a fixed 140ms minimum reset timeout after VCC rise.

It requires no external components for basic operation, supports bidirectional µP reset I/O via series resistor (e.g., 4.7kΩ), and maintains valid RESET state down to VCC = 1.0V-ensuring deterministic behavior during brownout recovery without pull-up dependency.

Key Specifications

Pinout & Package

MAX709MCPA+ is housed in an 8-pin plastic DIP package (0.300" wide), lead-free per RoHS, with pins 1–8 arranged as shown in top-view pinout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX706MCPA+, the MAX709MCPA+ omits manual reset and watchdog functions-reducing pin count, cost, and design overhead for pure power-fail detection. Versus TPS3808G33DBVR, it provides higher reset threshold accuracy for +5V systems but consumes more current and uses larger DIP packaging.

Availability

MAX709MCPA+ is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, automotive body electronics, and smart metering applications requiring stable component supply and long-term manufacturability.

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) designs high-performance analog and mixed-signal semiconductor solutions for industrial, communications, computing, and consumer markets.

The MAX709 belongs to Maxim's µP Supervisory Circuits product line, engineered specifically for deterministic power-fail detection and hardware reset generation in resource-constrained embedded systems without external timing components.

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 tolerance of ±0.15V over the full operating temperature range (–40°C to +85°C). This value is factory-trimmed and specified in the Electrical Characteristics table under "RESET Threshold, VTH" for suffix M. The threshold remains stable across temperature, with normalized variation ≤±0.5% from –60°C to +100°C per Typical Operating Characteristics data.

Does the MAX709MCPA+ require external components to function?

No, the MAX709MCPA+ requires no external components for core reset functionality. A 0.1µF ceramic bypass capacitor on VCC (pin 2) is recommended for transient immunity but not strictly required for basic operation. Unlike discrete solutions, it integrates precision voltage reference, comparator, and timing circuitry-eliminating resistors, capacitors, or diodes traditionally used in power-monitoring circuits.

Can the MAX709MCPA+ operate with VCC below 3.0V?

Yes, the MAX709MCPA+ operates with VCC as low as 1.0V and guarantees correct RESET output state down to that level. However, its 4.40V reset threshold means it will assert RESET continuously when VCC is below ~4.25V. Below 1.0V, RESET becomes high-impedance; for validity down to 0V, a 100kΩ pull-down resistor on the RESET pin is recommended per Applications Information.

What is the maximum allowable negative VCC transient duration the MAX709MCPA+ can ignore?

Per Figure 1 in the datasheet, the MAX709MCPA+ (as part of the MAX709L/M family) ignores negative VCC transients ≤40µs in duration when the magnitude is ≤100mV below the 4.40V threshold. For larger overdrive (e.g., 200mV), the maximum allowable pulse width decreases to ~15µs. This immunity is achieved via internal filtering and comparator hysteresis-no external RC network needed.

Is the MAX709MCPA+ pin-compatible with other MAX709 variants like MAX709RCPA+?

Yes, all MAX709 variants-including MAX709MCPA+, MAX709RCPA+, and MAX709TCPA+-share identical 8-pin DIP pinout, electrical interface, and functional behavior except for reset threshold voltage. The suffix (R/S/T/L/M) denotes only the factory-set threshold; all versions use the same die, package, and timing characteristics, enabling direct substitution where threshold requirements align.