Microchip Technology MCP795W22T-I/SL

Overview

MCP795W22T-I/SL from Microchip Technology is a battery-backed SPI Real-Time Clock/Calendar (RTCC) IC with integrated watchdog timer, dual event detectors, and 2 Kbit EEPROM. It maintains time to hundredth-of-second resolution across -40°C to +85°C, supports ±1 ppm digital trimming, logs power-fail/power-up timestamps, and operates from 1.8V–3.6V VCC or 1.3V–3.6V VBAT - used in industrial metering, medical logging, and backup-critical embedded systems.

For engineers reviewing the MCP795W22T-I/SL datasheet, MCP795W22T-I/SL pinout, MCP795W22T-I/SL application, or MCP795W22T-I/SL equivalent, this page delivers verified specifications, validated pin functions, confirmed EUI-64™ address capability, real-world timing accuracy data, and direct alternative part comparisons - all grounded in DS20002280E and Microchip's official documentation.

Technical Context

The MCP795W22T-I/SL implements a fully autonomous RTCC using an internal 32.768 kHz oscillator circuit optimized for 6–9 pF crystals, with on-chip digital trimming (±259 ppm range, ±1 ppm resolution) and automatic oscillator failure detection via OSCRUN flag. Its SPI interface runs up to 5 MHz at 2.5–3.6V and 3 MHz at 1.8–2.5V, with CS setup/hold times of 100 ns and data valid window of 100 ns.

It integrates three independent interrupt sources - dual alarms, high-speed event detect (pulse counting), and low-speed event detect (switch debouncing) - each assignable to either IRQ or WDO open-drain outputs. The device uses BCD-encoded time registers (0x00–0x1F), buffers reads to prevent rollover errors, and maintains SRAM/RTCC state during VCC dropout via seamless switchover at 1.3–1.7V VTRIP.

Key Specifications

Pinout & Package

14-pin SOIC (MCP795W22T-I/SL) and TSSOP packages; both share identical pin mapping and thermal characteristics per DS20002280E.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RTC/calendar applications.

Compared with MCP795W21T-I/SL, the MCP795W22T-I/SL adds EUI-64™ and 2 Kbit EEPROM for future-proofed networking; versus RV-3032-C3, it trades lower VBAT current for richer SPI-integrated functionality including alarms, event detection, and timestamped power monitoring.

Availability

MCP795W22T-I/SL is available at Aetrix Electronics and suitable for industrial energy metering, medical data logging, smart building HVAC control, and IoT edge node firmware update systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for MCP795W22T-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 devices, and timing solutions, headquartered in Chandler, Arizona, with global design and manufacturing operations.

The MCP795Wxx family was designed to deliver highly integrated, battery-backed RTC functionality with enhanced reliability features - including power-fail logging, dual alarms, and EUI programming - for industrial, medical, and infrastructure applications demanding deterministic timekeeping.

FAQ

What is the primary function of the MCP795W22T-I/SL?

The MCP795W22T-I/SL is a SPI-interfaced Real-Time Clock/Calendar IC that maintains accurate time and date (including hundredth-of-second resolution and leap-year compensation through 2399), logs power-fail/power-up events, and provides 2 Kbit EEPROM with factory-programmed EUI-64™ address. It operates autonomously from 1.8V–3.6V VCC or 1.3V–3.6V VBAT, making it ideal for mission-critical timing in industrial and medical systems where data integrity depends on precise timestamps.

Does the MCP795W22T-I/SL support external crystal oscillators?

Yes, the MCP795W22T-I/SL supports external 32.768 kHz tuning fork crystals on X1/X2 pins with built-in oscillator circuitry optimized for 6–9 pF load capacitance. It also supports external clock input on X1 (with X2 floating) when EXTOSC bit is set. Oscillator health is monitored via the OSCRUN flag in RTCWKDAY register, and digital trimming (±259 ppm range, ±1 ppm resolution) compensates for crystal tolerance and temperature drift - all confirmed in DS20002280E Sections 5.2 and 5.2.1.

How does the MCP795W22T-I/SL handle power loss and recovery?

The MCP795W22T-I/SL automatically switches to VBAT backup supply when VCC drops below 1.3–1.7V (VTRIP), preserving RTCC registers and 64-byte SRAM contents. Crucially, it logs the exact time of power-fail (PWRDN registers) and power-up (PWRUP registers) events - a feature absent in basic RTCs. This timestamped switchover ensures forensic traceability in systems like energy meters or medical loggers where outage duration and timing must be audited.

What memory resources does the MCP795W22T-I/SL include?

The MCP795W22T-I/SL integrates 64-byte battery-backed SRAM (addresses 0x20–0x5F), 2 Kbit EEPROM (software write-protected, 1M endurance, page writes ≤8 bytes), and 128-bit protected EEPROM preprogrammed with EUI-64™ MAC address. All memory remains accessible via SPI instructions (READ/WRITE, EEREAD/EEWRITE, IDREAD/IDWRITE) and retains data during VCC dropout - enabling secure storage of calibration data, device identity, and application logs without MCU intervention.

Can the MCP795W22T-I/SL generate clock outputs?

Yes, the MCP795W22T-I/SL provides a configurable CLKOUT pin capable of generating 32.768 kHz, 1 kHz, 64 Hz, or 1 Hz square-wave outputs - selectable via SQWFS bits in CONTROL register. This eliminates the need for external dividers or MCU timer resources to drive real-time displays, LED blink patterns, or synchronous sampling clocks. When disabled, CLKOUT enters high-impedance state, reducing system power and noise coupling.