Microchip Technology MCP795W10T-I/ST

Overview

MCP795W10T-I/ST 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 32.768 kHz crystal or external clock input, delivers ±1 ppm digital trimming, and logs power-fail/power-up timestamps - used in industrial metering, medical devices, and data loggers requiring tamper-resistant timekeeping.

For engineers reviewing the MCP795W10T-I/ST datasheet, MCP795W10T-I/ST pinout, MCP795W10T-I/ST application, or MCP795W10T-I/ST equivalent, key selection criteria include its 14-pin SOIC/TSSOP package, 1.8–3.6 V operating range, 1.2 µA typical timekeeping current from V_CC, SPI interface up to 5 MHz, and dual programmable alarms with assignable IRQ/WDO outputs.

Technical Context

The MCP795W10T-I/ST implements a fully autonomous RTCC with BCD-encoded time registers (hundredths of seconds through year), leap-year compensation to 2399, and automatic switchover between V_CC and V_BAT (1.3–3.6 V). Its on-chip oscillator supports 6–9 pF crystals and includes ±259 ppm digital trimming with ±1 ppm resolution.

It integrates two independent event detection paths: high-speed EVHS for pulse counting and low-speed EVLS for mechanical switch debouncing. The dedicated WDO pin supports configurable watchdog timeout pulses, while CLKOUT provides selectable square-wave frequencies - all controlled via SPI commands including EEREAD, WRITE, UNLOCK, and CLRWDT.

Key Specifications

Pinout & Package

Package: 14-lead SOIC (MCP795W10T-I/ST) and TSSOP - RoHS-compliant, industrial temperature grade (-40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP795W10T-I/ST, MCP795W11T-I/ST adds preprogrammed MAC addressing without altering timing performance or power consumption, while DS3231M+ trades SPI flexibility and integrated peripherals for superior oscillator stability and I²C simplicity.

Availability

MCP795W10T-I/ST is available at Aetrix Electronics and suitable for smart metering, industrial data logging, medical diagnostics, and building automation systems requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for MCP795W10T-I/ST 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 product line delivers highly integrated, low-power SPI RTC/Calendar ICs designed for industrial, medical, and energy infrastructure applications demanding robust timekeeping, event detection, and secure nonvolatile memory.

FAQ

What is the primary function of the MCP795W10T-I/ST?

The MCP795W10T-I/ST is a battery-backed SPI Real-Time Clock/Calendar IC that maintains accurate time and date (including hundredths of seconds and leap-year compensation to 2399), logs power-fail/power-up events, and provides 1 Kbit EEPROM, 64-byte SRAM, dual alarms, and integrated watchdog/event detection. Its core role is autonomous, low-power timekeeping in mission-critical embedded systems.

Does the MCP795W10T-I/ST support external 32.768 kHz clock input?

Yes, the MCP795W10T-I/ST supports external 32.768 kHz clock input on the X1 pin. When enabled via the EXTOSC bit in the CONTROL register, the internal crystal oscillator is disabled and X2 is left floating. This mode bypasses crystal load capacitance matching requirements and improves immunity to board-level noise affecting the oscillator circuit.

How does the power-fail timestamp feature work in the MCP795W10T-I/ST?

The MCP795W10T-I/ST automatically logs the exact time of V_CC loss and restoration into dedicated PWRDNxxx and PWRUPxxx registers. These timestamps are captured during switchover to and from V_BAT backup power, using the same RTCC counters - enabling forensic analysis of power interruptions without host MCU intervention.

Can the MCP795W10T-I/ST operate from a 1.3 V backup supply?

Yes, the MCP795W10T-I/ST supports backup supply voltages from 1.3 V to 3.6 V. Its power-fail switchover threshold is specified as 1.3 V (min) to 1.7 V (max), ensuring reliable handover to battery before V_CC drops below functional levels. At 1.3 V V_BAT, timekeeping current is ≤850 nA - enabling multi-year operation on common coin cells.

What is the purpose of the EVHS and EVLS pins on the MCP795W10T-I/ST?

The EVHS (High-Speed Event Detect) and EVLS (Low-Speed Event Detect) pins provide dedicated hardware event capture: EVHS counts fast digital pulses (e.g., encoder ticks) and triggers IRQ upon reaching a programmable count, while EVLS debounces mechanical switch inputs with user-configurable timing - offloading timing-critical tasks from the host MCU and improving system responsiveness and reliability.