Analog Devices Inc./Maxim Integrated MAX814KCSA

Overview

MAX814KCSA from Maxim Integrated is a high-accuracy, low-power microprocessor supervisory circuit providing power-on reset, manual reset, and early power-fail warning functions for +5V systems. It features a 4.80V ±1% reset threshold, 200ms reset pulse width, active-low RESET output, and guaranteed valid reset assertion down to VCC = 1V. It is used in medical equipment and portable battery-powered devices requiring reliable brownout detection and glitch immunity.

For engineers reviewing the MAX814KCSA datasheet, MAX814KCSA pinout, MAX814KCSA application, or MAX814KCSA equivalent, key selection criteria include reset threshold accuracy (±1%), supply current (75µA max), low-voltage operation (valid to 1V), power-fail comparator reference (2.50V), and SO-8 package compatibility with legacy DIP footprints.

Technical Context

The MAX814KCSA implements a precision voltage comparator with ±1% worst-case reset threshold accuracy referenced to an internal bandgap, coupled with a 200ms monostable timer that ensures minimum reset pulse duration after VCC crossing. Its power-fail monitor compares PFI to a fixed 2.50V internal reference, independent of the reset comparator.

A dedicated low-line detector provides a secondary alert 60mV above the main reset threshold, enabling pre-brownout NMI signaling. The MR input includes a 150µA internal pullup and supports TTL/CMOS logic levels, allowing direct switch or open-drain interface without external biasing.

Key Specifications

Pinout & Package

MAX814KCSA is housed in an 8-pin SO (Small Outline) package with standard 1.27mm pitch, pin-compatible with industry-standard SOIC-8 footprints and functionally identical to the 8-pin PDIP variant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX814LCSA, MAX814KCSA offers higher reset threshold for tighter 5V tolerance compliance; compared with TPS3808G18DBVR, it delivers dual reset polarity, low-line warning, and 5V-system optimization-making it irreplaceable in medical and industrial controllers requiring deterministic brownout response.

Availability

MAX814KCSA is available at Aetrix Electronics and suitable for medical equipment, portable/battery-powered equipment, controllers, and intelligent instruments requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX814KCSA 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 demanding industrial, medical, and communications applications, emphasizing accuracy, reliability, and low power.

The MAX814 family targets microprocessor supervisory needs in safety-critical and battery-constrained systems, delivering ±1% reset accuracy, ultra-low quiescent current, and integrated early-warning functions like LOW LINE and PFO.

FAQ

What is the exact reset threshold voltage of the MAX814KCSA?

The MAX814KCSA has a factory-trimmed reset threshold of 4.80V with ±1% worst-case accuracy across temperature and supply voltage. This means the actual trip point falls between 4.752V and 4.848V under all specified operating conditions, ensuring reliable reset initiation before a 5V system violates its µP's minimum operating voltage.

Does the MAX814KCSA support both active-high and active-low reset outputs?

Yes, the MAX814KCSA provides dual reset outputs: pin 7 is active-low RESET, and pin 8 is active-high RESET - the logical inverse of pin 7. Both outputs are push-pull and fully specified across the operating range, enabling direct interface to µPs requiring either polarity without external inverters.

Can the MAX814KCSA monitor voltages other than VCC?

Yes - the MAX814KCSA's PFI pin accepts an externally derived voltage, such as from a resistor divider on a +12V rail or negative supply. When PFI falls below its 2.50V internal reference, PFO asserts low. This allows the MAX814KCSA to provide power-fail warning for auxiliary rails independent of VCC monitoring.

What is the purpose of the LOW LINE output on the MAX814KCSA?

The LOW LINE output on the MAX814KCSA asserts low when VCC drops to 60mV above the 4.80V reset threshold (i.e., ~4.86V), providing a deterministic pre-reset warning. This enables the µP to execute critical housekeeping tasks - such as saving state or disabling peripherals - before the main RESET signal activates 200ms later.

Is the MAX814KCSA compatible with lead-free soldering processes?

Yes, the MAX814KCSA is available in lead-free packaging. When ordering, append the "+" symbol to the part number (e.g., MAX814KCSA+) to specify RoHS-compliant, lead-free termination. The SO-8 package meets JEDEC J-STD-020 moisture sensitivity level 1 and withstands standard reflow profiles including peak temperatures up to 260°C.