Analog Devices Inc./Maxim Integrated MAX814LCPA+

Overview

MAX814LCPA+ 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 4.70V ±1% reset threshold, 200ms reset pulse width, guaranteed RESET validity down to VCC = 1V, and 75µA max supply current. It is used in medical equipment and portable battery-powered devices requiring reliable brownout detection and deterministic reset timing.

For engineers reviewing the MAX814LCPA+ datasheet, MAX814LCPA+ pinout, MAX814LCPA+ application, or MAX814LCPA+ equivalent, this page delivers verified functional specifications, validated package mapping (8-pin PDIP), confirmed pin roles, and real-world design context for µP reset supervision in commercial-temperature embedded systems.

Technical Context

The MAX814LCPA+ implements a precision voltage comparator with ±1% worst-case reset threshold accuracy referenced to a trimmed internal bandgap, coupled with a 200ms monostable timer that ensures minimum reset assertion duration after VCC crossing. Its low-line detector provides an independent 60mV-above-reset-threshold warning output (LOW LINE) with 2mV hysteresis.

It integrates a 150µA internal MR pull-up, power-fail comparator with 2.50V reference (PFI/PFO), and glitch-immune reset logic that ignores transients ≤30µs at 100mV overdrive. Unlike the MAX815/MAX816 variants, it lacks watchdog or adjustable reset functionality - its architecture is optimized exclusively for fixed-threshold, dual-output (active-low and active-high RESET) supervision of +5V rails.

Key Specifications

Pinout & Package

MAX814LCPA+ is housed in an 8-pin plastic DIP (PDIP) package, RoHS-compliant and lead-free (indicated by '+' suffix). Pin spacing is 0.300", body width 0.355", and it supports through-hole mounting with standard wave solder profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX814LCSA+, the MAX814LCPA+ offers identical supervision functionality but enables through-hole prototyping and higher thermal mass; compared with TPS3808G18DBVR, it delivers higher reset voltage accuracy, dual-output flexibility, and integrated low-line warning - critical for robust +5V system reliability.

Availability

MAX814LCPA+ is available at Aetrix Electronics and suitable for medical diagnostics, industrial PLCs, handheld test instruments, and set-top box power management requiring stable component supply across long production lifecycles.

Supply support for MAX814LCPA+ 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 high accuracy, low power, and robustness.

The MAX814LCPA+ belongs to Maxim's µP supervisory product line, engineered specifically for deterministic reset generation, brownout immunity, and early power-fail warning in commercial-temperature +5V embedded systems.

FAQ

What is the exact reset threshold voltage of the MAX814LCPA+?

The MAX814LCPA+ has a factory-trimmed reset threshold of 4.70V ±1%, meaning it asserts reset when VCC falls below 46.53V (min) and releases reset when VCC rises above 4.747V (max) across temperature and supply variation. This value is fixed and defined by the 'L' suffix per Maxim's ordering nomenclature - no external adjustment is possible. The MAX814LCPA+ uses this threshold to ensure compatibility with standard +5V power supplies operating within ±5% tolerance.

Does the MAX814LCPA+ include a watchdog timer function?

No, the MAX814LCPA+ does not include a watchdog timer. It is the base variant in the MAX814/MAX815/MAX816 family and provides only power-on reset, manual reset, power-fail monitoring (PFI/PFO), and low-line warning (LOW LINE). The watchdog function is exclusive to the MAX815 series (e.g., MAX815LCPA+), which adds WDI/WDO pins and a 1.56s timeout. Using MAX814LCPA+ in a design requiring watchdog supervision would necessitate adding external logic or selecting the MAX815 variant.

Can the MAX814LCPA+ monitor voltages other than VCC?

Yes, the MAX814LCPA+ can monitor auxiliary voltages using its PFI input. By connecting a resistor divider from the target voltage (e.g., +12V) to PFI, and referencing it to the internal 2.50V comparator threshold, early warning can be generated before the monitored rail fails. For example, a 340kΩ/100kΩ divider on +12V yields ~2.73V at PFI - dropping below 2.50V when +12V falls to ~11.0V. The PFO output then signals the µP to initiate shutdown. This capability is documented in Figure 11 of the MAX814LCPA+ datasheet.

What is the purpose of the LOW LINE pin on the MAX814LCPA+?

The LOW LINE pin on the MAX814LCPA+ is an active-low warning output that asserts when VCC drops 60mV above the main reset threshold (i.e., at ~4.76V for the L-version). It provides a pre-reset alert, giving the system 100–200ms of advance notice to save critical data or disable peripherals before full reset occurs. Unlike RESET, LOW LINE has no minimum pulse width and returns high immediately when VCC recovers - making it ideal for triggering non-maskable interrupts (NMI) or watchdog reloads without disrupting normal operation.

Is the MAX814LCPA+ compatible with 3.3V microcontrollers?

Yes, the MAX814LCPA+ is compatible with 3.3V microcontrollers for reset signaling. Its RESET and RESET pins are push-pull CMOS outputs with VOH ≥ VCC − 1.5V and VOL ≤ 0.4V, ensuring valid logic levels when interfaced to 3.3V I/O - provided the µP's reset pin is designed for active-low assertion and tolerates 5V-tolerant inputs. However, the device itself requires a +5V supply (4.75–5.5V) and cannot operate from 3.3V; it is not a 3.3V-supply supervisory IC like the MAX814T variant.