Microchip Technology MCP795W11T-I/SL

Overview

MCP795W11T-I/SL from Microchip Technology is a battery-backed SPI Real-Time Clock/Calendar (RTCC) IC with integrated watchdog timer, dual event detect modules, 1 Kbit EEPROM, and 64-byte SRAM. It maintains time to hundredth-of-second resolution across -40°C to +85°C, supports 12/24-hour mode with leap-year compensation through 2399, and logs power-fail/power-up timestamps. Used in industrial control panels requiring precise, low-power timekeeping with tamper-resistant MAC storage.

For engineers reviewing the MCP795W11T-I/SL datasheet, MCP795W11T-I/SL pinout, MCP795W11T-I/SL application, or MCP795W11T-I/SL equivalent, key selection criteria include ±1 ppm digital trimming range, 1.0 µA VBAT timekeeping current, EUI-48™ preprogrammed address, dual alarm assignment to IRQ/WDO pins, and 14-pin SOIC/TSSOP package compatibility with 32.768 kHz crystal load capacitance of 6–9 pF.

Technical Context

The MCP795W11T-I/SL implements a fully autonomous RTCC subsystem using an internal 32.768 kHz oscillator circuit optimized for external crystals with 6–9 pF load capacitance, plus on-chip digital trimming (±259 ppm range, ±1 ppm resolution). Its SPI interface operates up to 5 MHz at 2.5–3.6 V and 3 MHz at 1.8–2.5 V, with CS setup/hold times of 100 ns and data valid delay of 100 ns under nominal conditions.

Power management includes automatic switchover between VCC (1.8–3.6 V) and VBAT (1.3–3.6 V) with programmable 1.3–1.7 V trip point, while maintaining timekeeping current as low as 1.0 µA from VBAT at 3.0 V. The device integrates two independent event detectors - high-speed pulse counter and low-speed switch debouncer - each with configurable interrupt outputs routed to IRQ or WDO pins.

Key Specifications

Pinout & Package

Package: 14-pin SOIC (MCP795W11T-I/SL) and TSSOP; RoHS-compliant, surface-mount, 3.9 mm × 8.7 mm body size.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar real-time clock/calendar applications.

Compared with MCP795W12T-I/SL, the MCP795W11T-I/SL delivers identical real-time performance and feature depth but substitutes EUI-48™ for EUI-64™-reducing cost and footprint where 48-bit addressing suffices. Against DS3231M+, it trades integrated TCXO accuracy for programmable digital trimming, SPI interface, dual event inputs, and factory-programmed MAC, making it better suited for feature-rich, cost-sensitive industrial endpoints.

Availability

MCP795W11T-I/SL is available at Aetrix Electronics and suitable for industrial energy metering, medical device logging, smart building HVAC control, and industrial PLC real-time scheduling requiring stable component supply across extended production lifecycles.

Supply support for MCP795W11T-I/SL 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

Microchip Technology Inc. is a leading provider of microcontrollers, analog components, and timing solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The MCP795Wxx family is designed for embedded systems requiring autonomous, low-power timekeeping with integrated event handling, watchdog supervision, and secure identity storage-targeting industrial, medical, and infrastructure applications.

FAQ

What is the primary function of the MCP795W11T-I/SL?

The MCP795W11T-I/SL is a battery-backed SPI Real-Time Clock/Calendar IC that maintains accurate time and date-including hundredths of seconds, leap-year compensation through 2399, and 12/24-hour format-while providing integrated features such as dual alarms, watchdog timer, high/low-speed event detection, 1 Kbit EEPROM, and factory-programmed EUI-48™. It serves as a self-contained timing subsystem in industrial and medical electronics.

Does the MCP795W11T-I/SL require an external crystal?

Yes, the MCP795W11T-I/SL is optimized for use with a 32.768 kHz tuning fork crystal connected between X1 and X2 pins, with external load capacitors matching the crystal's specified 6–9 pF load capacitance. Alternatively, it supports an external 32.768 kHz clock applied to the X1 pin with X2 left floating-enabling crystal-free operation when system-level timing is available.

How does the power-fail timestamp feature work in the MCP795W11T-I/SL?

The MCP795W11T-I/SL automatically logs the exact time of VCC loss (power-down timestamp) and VCC restoration (power-up timestamp) into dedicated registers (0x18–0x1B and 0x1C–0x1F). This occurs during switchover between main supply and VBAT, without host intervention, enabling post-event diagnostics and compliance reporting in mission-critical systems using the MCP795W11T-I/SL.

What is the purpose of the EVHS and EVLS pins on the MCP795W11T-I/SL?

The EVHS (pin 11) and EVLS (pin 12) pins provide dedicated hardware event detection: EVHS accepts high-frequency pulses (e.g., from encoders or communication lines) and triggers IRQ after a programmable count; EVLS accepts low-speed mechanical inputs (e.g., pushbuttons or limit switches) and applies user-selectable debounce filtering before asserting IRQ. Both operate independently and retain state during VBAT-only operation.

Can the MCP795W11T-I/SL generate a clock output signal?

Yes, the MCP795W11T-I/SL provides a configurable square-wave clock output on the CLKOUT pin (pin 13). Supported frequencies include 32.768 kHz, 1024 Hz, 32 Hz, and 1 Hz, selected via SQWFS bits in the CONTROL register. This output can drive secondary timing circuits, LEDs, or microcontroller peripherals-eliminating the need for external clock dividers in many designs using the MCP795W11T-I/SL.