Analog Devices Inc./Maxim Integrated MAX801LCSA+

Overview

MAX801LCSA+ from Maxim Integrated is a +5V microprocessor supervisory IC providing precision reset generation, battery switchover, low-line warning (NMI), and watchdog timer functionality. It features ±1.5% reset threshold accuracy (4.675V), 200ms reset timeout, 1.6s watchdog timeout, and operates across 0°C to +70°C in 8-pin SO package. Used in portable/battery-powered equipment for reliable µP power-up sequencing and brownout protection.

For engineers reviewing the MAX801LCSA+ datasheet, MAX801LCSA+ pinout, MAX801LCSA+ application, or MAX801LCSA+ equivalent, this page delivers verified technical context, real-world timing behavior, battery-backup mode operation, watchdog interaction logic, and validated alternative options - all grounded in Maxim's official specifications for the L-suffix, SO-packaged variant.

Technical Context

The MAX801LCSA+ integrates three independent comparators: reset (4.675V ±1.5%), low-line (4.727V, 52mV above reset), and battery switchover (VBATT + 0.05V on rise, VBATT on fall). Its BiCMOS process enables 68µA typical VCC supply current and guarantees RESET validity down to VCC = 1V.

It implements a state-machine-based watchdog with 1.6s timeout (±20%), cleared only by WDI transitions while RESET is deasserted; unconnected WDI disables the function via internal voltage divider. The active-low RESET output uses strong pull-down/weak pull-up architecture, while RESET provides full CMOS drive capability.

Key Specifications

Pinout & Package

MAX801LCSA+ is housed in an 8-pin SO (Small Outline) package, RoHS-compliant with lead-free finish (+ suffix). Pin spacing is 1.27mm, body width 3.9mm, and total length 4.9mm - compatible with IPC-7351B SOIC-8 footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX801LCSA+, MAX809LCSA+ reduces feature set and accuracy for cost-sensitive reset-only use, while TPS3808G18DBVR trades integrated supervision (watchdog, low-line, battery switch) for adjustable threshold and lower IQ - making MAX801LCSA+ uniquely suited for battery-backed µP systems needing coordinated reset, warning, and power-path control.

Availability

MAX801LCSA+ is available at Aetrix Electronics and suitable for portable medical monitors, industrial PLC controllers, smart energy meters, and point-of-sale terminals requiring stable component supply with long-term lifecycle support.

Supply support for MAX801LCSA+ 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 ICs for power, sensing, and interface applications - emphasizing precision, reliability, and integration.

The MAX801LCSA+ belongs to Maxim's µP supervisory product line, engineered specifically for battery-powered and mission-critical embedded systems requiring coordinated reset, low-line warning, watchdog monitoring, and seamless backup power management.

FAQ

What is the exact reset threshold voltage for MAX801LCSA+?

The MAX801LCSA+ has a nominal reset threshold of 4.675V with ±1.5% accuracy over temperature and supply variation. This value is fixed by the 'L' suffix and confirmed in Maxim's Electrical Characteristics table under VRST for MAX80_L devices. The threshold remains stable across the 0°C to +70°C operating range, with typical drift less than 10mV per 100°C as shown in the RESET THRESHOLD vs. TEMPERATURE graph.

Does MAX801LCSA+ support battery backup, and what are the limits?

Yes, MAX801LCSA+ supports battery backup via the BATT pin, automatically switching the OUT rail from VCC to VBATT when VCC falls below both the reset threshold (4.675V) and VBATT. It delivers up to 20mA from battery in backup mode with ≤12Ω on-resistance, and VBATT may range from 2.8V to 6V. The device draws less than 1µA from the battery during backup, enabling multi-year operation with common coin cells or supercapacitors.

How does the watchdog timer in MAX801LCSA+ operate?

The MAX801LCSA+ watchdog timer asserts RESET for 200ms if the WDI pin remains static longer than 1.6s (±20%). The timer clears only on rising or falling edges at WDI while RESET is deasserted - not on level holds. Leaving WDI unconnected disables the watchdog via an internal voltage divider that biases it near VCC/2. This behavior is explicitly documented in the MAX801 Watchdog Timer section and Figure 5 timing diagram.

Can MAX801LCSA+ generate a non-maskable interrupt (NMI)?

Yes, MAX801LCSA+ provides an NMI-capable signal via the LOWLINE pin, which goes active-low when VCC falls to 4.727V - precisely 52mV above the 4.675V reset threshold. This early warning allows µP firmware to execute an orderly shutdown before RESET asserts. LOWLINE has CMOS-compatible drive strength and 13mV hysteresis, ensuring noise-immune triggering as specified in the Electrical Characteristics table under VLL and VLR parameters.

Is MAX801LCSA+ pin-compatible with other MAX80x variants?

Yes, MAX801LCSA+ shares identical 8-pin SO pinout with all MAX801/MAX808 variants including MAX801MCSA+, MAX801NCSA+, MAX808LCSA+, and MAX808MCSA+. Pin functions (VCC, GND, RESET, LOWLINE, etc.) are fully consistent across the family, as confirmed in the Pin Description section and Functional Diagram (Figure 1). Differences exist only in reset threshold (L/M/N), presence of WDI/CE features, and temperature grade - not in physical or electrical pin mapping.