Analog Devices Inc./Maxim Integrated MAX802LCSA

Overview

The MAX802LCSA from Maxim Integrated is a microprocessor supervisory circuit providing reset generation, battery-backup switchover, watchdog timeout, and power-fail detection for +5V systems. It asserts an active-low RESET pulse during power-up (VCC ≥ 1V), brownout (VCC < 4.65V), and watchdog timeout (1.6s), while switching VOUT to VBATT when VCC drops below threshold-enabling reliable CMOS RAM retention in battery-powered controllers.

For engineers reviewing the MAX802LCSA datasheet, MAX802LCSA pinout, MAX802LCSA application, or MAX802LCSA equivalent, this page delivers verified functional identity, confirmed 8-pin SO package mapping, validated 4.65V reset threshold and 200ms pulse width, battery-switching behavior under VCC/VBATT hysteresis, and two manufacturer-confirmed alternative parts with documented technical differences.

Technical Context

The MAX802LCSA integrates four independent functions: a precision reset generator with 4.65V ±2% threshold and 200ms delay; a 1.6s watchdog timer cleared by WDI edges or RESET assertion; a 1.25V reference-based power-fail comparator (PFI/PFO); and a dual-path power switch routing VCC or VBATT to VOUT based on voltage comparison with 40mV hysteresis.

Its internal architecture separates reset logic from battery switchover and power-fail detection-allowing simultaneous operation without interference. The device guarantees RESET assertion down to VCC = 1V and draws only 200µA quiescent current in normal operation and 50nA in battery-backup mode, making it suitable for low-power embedded systems requiring deterministic startup and fail-safe shutdown.

Key Specifications

Pinout & Package

MAX802LCSA is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package with standard 1.27mm pitch, RoHS-compliant lead-free finish, and JEDEC MS-012AC outline.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX802MCSA, the MAX802LCSA offers higher reset threshold for tighter +5V regulation tolerance; compared with MAX706SCSA, it lacks MR input but achieves lower 50nA backup current-making it optimal for long-life battery-backed memory retention without manual intervention.

Availability

MAX802LCSA is available at Aetrix Electronics and suitable for battery-powered controllers, critical μP power monitoring, and intelligent instrumentation requiring stable component supply across industrial temperature ranges (0°C to +70°C).

Supply support for MAX802LCSA 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 industrial, medical, and communications applications, emphasizing reliability, low power, and integration.

The MAX802LCSA belongs to Maxim's microprocessor supervisory circuit family, engineered specifically to replace discrete reset generators, battery switches, and voltage monitors in space-constrained embedded systems with single-chip hardware reset assurance.

FAQ

What is the guaranteed reset threshold voltage for MAX802LCSA?

The MAX802LCSA has a guaranteed reset threshold of 4.65V ±2% over temperature and supply variations. This value is specified in the Electrical Characteristics table for MAX802L devices at TA = +25°C with VCC falling, and applies to the MAX802LCSA variant in 8-pin SO package. The threshold ensures reset assertion occurs before the +5V supply enters the microprocessor's invalid operating region, supporting robust system startup and brownout recovery.

Does MAX802LCSA support battery-backup switchover, and what is its quiescent current in that mode?

Yes, MAX802LCSA supports automatic battery-backup switchover: when VCC drops below 4.65V, it connects VBATT to VOUT if VBATT exceeds VCC by 20mV. In battery-backup mode, the MAX802LCSA draws only 50nA quiescent current (typical) at TA = +25°C with VCC = 0V and VBATT = 2.8V-enabling multi-year RAM retention using standard 3.6V lithium batteries without significant self-discharge impact.

What is the watchdog timeout period for MAX802LCSA, and how is it cleared?

The MAX802LCSA features a fixed 1.6s watchdog timeout period, with typical value 1.60s and min/max bounds of 1.00s and 2.25s. The internal timer is cleared by any rising or falling edge on the WDI pin, by assertion of the RESET output, or by three-stating WDI. If WDI remains static (high or low) for longer than the timeout, RESET pulses low for 200ms. This behavior is confirmed in the Electrical Characteristics and Detailed Description sections of the datasheet.

Can MAX802LCSA monitor power supplies other than +5V, and how is this implemented?

Yes, MAX802LCSA can monitor non-+5V supplies using its PFI input and internal 1.25V reference. An external resistor divider scales the target supply voltage so that PFI reaches 1.25V at the desired trip point-for example, monitoring a +3.3V rail by setting R1/R2 ratio to produce 1.25V at 3.0V input. The PFI input draws only ±25nA, minimizing divider error. This capability is explicitly described in the Applications Information section under "Power-Fail Comparator" and "Monitoring a Negative Voltage."

What package type and temperature range does MAX802LCSA use?

MAX802LCSA uses an 8-pin SOIC (Small Outline Integrated Circuit) package with 1.27mm lead pitch and operates over the commercial temperature range of 0°C to +70°C. This is confirmed in the Ordering Information table, where "MAX802LCSA" is listed with "8 SO" package and "0°C to +70°C" temperature range. The SOIC package supports surface-mount assembly and meets JEDEC MS-012AC mechanical specifications.