Microchip Technology MCP795B10T-I/ST

Overview

MCP795B10T-I/ST from Microchip Technology is a SPI real-time clock/calendar (RTCC) IC with integrated 32 kHz boot-up clock, 64-byte battery-backed SRAM, and 1 Kbit EEPROM. It delivers accurate timekeeping (hours/minutes/seconds/hundredths/day/month/year/leap year), supports dual programmable alarms with IRQ/WDO outputs, and features digital trimming (±255 ppm in 1 ppm steps) for precision timing in industrial power meters and data loggers.

For engineers reviewing the MCP795B10T-I/ST datasheet, MCP795B10T-I/ST pinout, MCP795B10T-I/ST application, or MCP795B10T-I/ST equivalent, this device offers verified battery switchover (1.3–5.5 V VBAT), <700 nA VBAT timekeeping current at 1.8 V, 10 MHz SPI interface, and hardware watchdog with dedicated WDO pin - critical for fail-safe embedded timing in unattended systems.

Technical Context

The MCP795B10T-I/ST implements a crystal-based RTCC core with automatic oscillator start on power-up and 32 kHz boot-clock generation on CLKOUT/BOOT. Its dual-event detection system includes EVHS (pulse-counting: 1st/4th/16th/32nd edge) and EVLS (debounced: 31 ms / 500 ms), both operable from VCC or VBAT.

It integrates a programmable watchdog timer with dual retrigger capability (via SPI or EVHS), power-fail time-stamping (logging VCC loss/restoration), and on-chip digital calibration. The device uses BCD-encoded time registers (0x00–0x1F), supports 12-/24-hour format, and maintains SRAM and RTC state during VCC dropout via seamless VBAT switchover at 1.3–1.7 V threshold.

Key Specifications

Pinout & Package

Package: 14-lead SOIC (Small Outline Integrated Circuit), surface-mount, RoHS-compliant.

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, the MCP795B10T-I/ST adds guaranteed 32 kHz boot-clock output and retains identical SRAM, EEPROM, alarms, and watchdog features; versus DS3231M+, it trades TCXO-grade accuracy for integrated memory, event inputs, and lower VBAT current - making it optimal for cost-sensitive, feature-rich embedded timing.

Availability

MCP795B10T-I/ST is available at Aetrix Electronics and suitable for smart metering, industrial data logging, medical infusion pumps, and building automation systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MCP795B10T-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, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with high-reliability silicon and development tools.

The MCP795XXX product line delivers integrated real-time clock/calendar ICs with battery switchover, nonvolatile memory, and enhanced system peripherals - designed specifically for robust, low-power timing in resource-constrained embedded applications.

FAQ

What is the primary function of the MCP795B10T-I/ST?

The MCP795B10T-I/ST is a SPI real-time clock/calendar IC that provides accurate timekeeping (hours/minutes/seconds/hundredths/day/month/year/leap year), battery-backed SRAM, EEPROM, dual alarms, watchdog, and event detection. Its 32 kHz boot-up clock ensures immediate timing availability at power-on - a key differentiator from non-B variants like MCP795W10T-I/ST. The MCP795B10T-I/ST is engineered for industrial and medical systems demanding reliable, low-power timekeeping with data retention.

Does the MCP795B10T-I/ST require an external crystal?

Yes, the MCP795B10T-I/ST requires an external 32.768 kHz tuning fork crystal connected between X1 and X2 pins. It does not include an integrated oscillator; however, it supports external CMOS clock input on X1 (with X2 left unconnected) as an alternative. The MCP795B10T-I/ST also features on-chip digital trimming (±255 ppm in 1 ppm steps) to compensate for crystal tolerance and aging - eliminating need for external load capacitors in many designs.

How does the battery switchover work on the MCP795B10T-I/ST?

The MCP795B10T-I/ST automatically switches from VCC to VBAT when VCC drops below the 1.3–1.7 V switchover threshold (typical 1.5 V). During switchover, it logs timestamps for both power loss and restoration in dedicated registers (0x18–0x1F). VBAT powers the RTC, 64-byte SRAM, and calibration registers continuously - ensuring no time or data loss. The MCP795B10T-I/ST draws <700 nA from VBAT at 1.8 V, enabling multi-year operation on standard coin cells.

What are the key differences between MCP795B10T-I/ST and MCP795W10T-I/ST?

The MCP795B10T-I/ST includes a 32 kHz boot-up clock asserted on CLKOUT/BOOT at power-on, while the MCP795W10T-I/ST does not. Both share identical SRAM (64 B), EEPROM (1 Kbit), alarms, watchdog, event inputs, and digital trimming. The MCP795B10T-I/ST's boot-clock eliminates crystal startup delay in time-critical applications - a functional distinction confirmed in Microchip's Device Selection Table and Section 9.1.2 of DS22280A. No other electrical or functional differences exist between these variants.

Can the MCP795B10T-I/ST generate multiple clock frequencies on CLKOUT/BOOT?

Yes, the MCP795B10T-I/ST supports four selectable CLKOUT frequencies: 1 Hz, 4.096 kHz, 8.192 kHz, and 32.768 kHz - configured via RS2:RS0 bits (0x08:2–0). Additionally, it asserts 32 kHz on CLKOUT/BOOT at power-up (a B-series exclusive feature), then transitions to the programmed frequency after initialization. This dual-mode behavior is documented in the Clockout Function section and distinguishes the MCP795B10T-I/ST from W-series parts, which lack boot-clock assertion.