Analog Devices Inc./Maxim Integrated MAX807NEPE

Overview

The MAX807NEPE from Maxim Integrated is a full-featured microprocessor supervisory circuit designed for critical power monitoring in 5V µP systems. It provides ±1.5% precise reset threshold (4.575V), active-low and active-high RESET outputs, independent watchdog timer (1.6s timeout), two-stage power-fail warning (2.275V PFI threshold + 52mV low-line offset), and automatic battery switchover with 250mA VCC-mode / 20mA battery-backup output drive - enabling reliable operation in portable instrumentation and industrial controllers.

For engineers reviewing the MAX807NEPE datasheet, MAX807NEPE pinout, MAX807NEPE application, or MAX807NEPE equivalent, this device delivers verified reset accuracy, guaranteed RESET validity down to VCC = 1V, 2ns CE gate propagation delay, and BATT OK status flag - key selection criteria for battery-backed real-time clock and CMOS RAM retention designs requiring deterministic brownout response.

Technical Context

The MAX807NEPE integrates six comparators (reset, low-line, power-fail, BATT OK, battery switchover, watchdog transition detector) and a state machine with internal oscillator, all implemented in BiCMOS technology to achieve ±1.5% reset threshold accuracy and 70µA typical supply current. Its dual-reset architecture supports both system initialization and orderly shutdown via LOW LINE NMI assertion 52mV above the reset threshold.

Chip-enable gating uses a series transmission gate (75Ω on-resistance, 2ns propagation delay at 50pF load) disabled during reset to prevent RAM corruption; backup switchover employs voltage-controlled NMOS/PMOS switching between VCC and VBATT, with BATT ON output driving external PNP/PMOS for >250mA loads. Watchdog timeout is fixed at 1.6s (typ), cleared only on WDI transition or RESET assertion.

Key Specifications

Pinout & Package

MAX807NEPE is supplied in a 16-pin plastic DIP package (0.300" wide), RoHS-compliant and rated for industrial temperature range (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MAX807NEPE, MAX809SEUS+T omits all supervision extensions (watchdog, low-line, battery control), while TPS3823MPDBVR targets lower-voltage domains and excludes the 52mV early-warning window and automatic switchover - making MAX807NEPE uniquely suited for 5V battery-backed µP systems requiring layered power integrity assurance.

Availability

MAX807NEPE is available at Aetrix Electronics and suitable for industrial programmable logic controllers, portable medical instruments, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX807NEPE 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) is a semiconductor company specializing in high-performance analog, mixed-signal, and power management ICs for industrial, automotive, and computing applications.

The MAX807 family was engineered to deliver precision power supervision for µP-based systems demanding deterministic reset behavior, battery-backed memory retention, and early power-fail warning - targeting portable, industrial, and mission-critical embedded platforms.

FAQ

What is the exact reset threshold voltage of the MAX807NEPE?

The MAX807NEPE has a nominal reset threshold of 4.575V with ±1.5% accuracy over temperature and supply voltage. This value is specified in the Electrical Characteristics table under "VRST" for the MAX807N variant and confirmed in the ordering information section. The threshold remains stable across the –40°C to +85°C operating range, ensuring consistent µP reset behavior in industrial environments.

Does the MAX807NEPE support automatic switchover to backup battery during main supply failure?

Yes, the MAX807NEPE supports fully automatic battery switchover. When VCC falls below the reset threshold and VBATT exceeds 2.0V, the internal switch disconnects VCC from OUT and connects BATT to OUT. The BATT ON output goes high to signal this transition, and the device delivers up to 20mA from the battery to sustain CMOS RAM or RTC circuits without external components.

Can the MAX807NEPE generate an early warning interrupt before system reset occurs?

Yes, the MAX807NEPE provides a dedicated LOW LINE output that asserts low when VCC falls to 52mV above the reset threshold (i.e., at ~4.627V). This enables a non-maskable interrupt (NMI) to initiate an orderly software shutdown - such as saving volatile data or disabling peripherals - before the 4.575V reset threshold is reached and µP execution halts.

What is the watchdog timeout period of the MAX807NEPE, and how is it triggered?

The MAX807NEPE watchdog timeout period is 1.6 seconds (typical). It is triggered when the WDI input remains static (high or low) for longer than this interval. A transition (edge) on WDI clears the timer and keeps WDO high. If no edge occurs, WDO goes low - and when wired to MR, this generates a 200ms reset pulse every 1.6s until activity resumes.

Is the MAX807NEPE pinout compatible with other MAX807 variants like MAX807LEPE or MAX807MEPE?

Yes, the MAX807NEPE shares identical pinout, package (16-pin DIP), and functional block diagram with MAX807LEPE and MAX807MEPE. The only difference is the reset threshold voltage (4.575V for N, 4.675V for L, 4.425V for M); all other electrical characteristics, timing, and interface behavior are identical across the MAX807L/M/N family.