Microchip Technology MCP795B10T-I/SL

Overview

MCP795B10T-I/SL from Microchip Technology is a SPI real-time clock/calendar (RTCC) IC with integrated 64-byte battery-backed SRAM, 1 Kbit EEPROM, and dual programmable alarms. It features 32 kHz boot-up clock at power-up, digital trimming (±255 ppm), power-fail time-stamping, and operates from 1.8V to 5.5V VCC or 1.3V to 5.5V VBAT - used in industrial metering, backup power systems, and embedded data loggers requiring precise timekeeping under brownout conditions.

For engineers reviewing the MCP795B10T-I/SL datasheet, MCP795B10T-I/SL pinout, MCP795B10T-I/SL application, or MCP795B10T-I/SL equivalent, key selection criteria include VBAT switchover voltage (1.3–1.7 V), <700 nA timekeeping current at 1.8 V, 10 MHz SPI interface, 32 kHz CLKOUT/BOOT functionality, and support for EUI-48™/EUI-64™ unique ID programming.

Technical Context

The MCP795B10T-I/SL implements a crystal-based RTCC with digital calibration logic that adjusts timekeeping by ±255 ppm in 1 ppm steps per minute. Its oscillator block accepts external 32.768 kHz tuning fork crystals on X1/X2 and supports external CMOS clock input via X1 when X2 is NC.

It integrates dual event detect inputs (EVHS/EVLS) - EVHS supports pulse counting (1st/4th/16th/32nd edge), while EVLS provides programmable debounce (31 ms or 500 ms). The device uses a dedicated WDO pin for watchdog output and shares IRQ for alarms and events, both open-drain with 10 mA sink capability.

Key Specifications

Pinout & Package

Package: 14-lead SOIC (Small Outline Integrated Circuit), RoHS-compliant, surface-mount, 3.9 mm × 8.7 mm footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP795W10T-I/SL, the MCP795B10T-I/SL adds guaranteed 32 kHz clock output at power-up - eliminating startup delay in time-sensitive boot sequences. Versus DS3231M+, it trades ±2 ppm TCXO accuracy for integrated event detection, watchdog, and lower VBAT current, making it more suitable for cost-constrained, feature-rich embedded systems.

Availability

MCP795B10T-I/SL is available at Aetrix Electronics and suitable for industrial metering, medical device logging, and POS terminal applications requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MCP795B10T-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 U.S.-based semiconductor manufacturer specializing in microcontrollers, analog devices, and timing solutions, with global manufacturing and quality certifications including ISO 9001 and AEC-Q200 for automotive-grade parts.

The MCP795XXX product line delivers highly integrated SPI real-time clock/calendars with battery switchover, event detection, and nonvolatile memory - designed for industrial, medical, and metering systems needing robust timekeeping under variable power conditions.

FAQ

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

The MCP795B10T-I/SL is a SPI real-time clock/calendar IC with integrated 64-byte battery-backed SRAM and 1 Kbit EEPROM. Its core function is to maintain accurate time and date across power cycles using an external 32.768 kHz crystal, while supporting alarms, event detection, watchdog timer, and power-fail timestamping. The MCP795B10T-I/SL specifically guarantees 32 kHz clock output at power-up - a key differentiator from the W-series variants.

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

Yes, the MCP795B10T-I/SL requires an external 32.768 kHz tuning fork crystal connected between X1 and X2 pins for standard operation. However, it also supports external CMOS clock input on X1 (with X2 left unconnected) via the EXTOSC bit in Control Register 0x08. The MCP795B10T-I/SL does not include an internal oscillator - crystal or external clock is mandatory for timekeeping.

How does the VBAT switchover work on the MCP795B10T-I/SL?

The MCP795B10T-I/SL automatically switches from VCC to VBAT when VCC drops below the switchover threshold of 1.3–1.7 V (typical 1.5 V). This transition preserves RTC register contents, SRAM data, and oscillator operation. The VBATEN bit (Register 0x04:3) must be set to enable VBAT connection. The MCP795B10T-I/SL also logs timestamps at both power-down and power-up via dedicated registers (0x18–0x1F and 0x1C–0x1F).

What memory resources are available on the MCP795B10T-I/SL?

The MCP795B10T-I/SL provides three memory types: (1) 64-byte battery-backed SRAM (addresses 0x20–0x5F), retained during VCC loss; (2) 1 Kbit (128-byte) EEPROM with software write-protection and page-write capability; and (3) a protected 128-bit unique ID space supporting EUI-48™ or EUI-64™ MAC addresses. All memory is accessible via SPI, and the MCP795B10T-I/SL supports up to 1 million EEPROM write cycles.

Can the MCP795B10T-I/SL generate multiple clock frequencies?

Yes, the MCP795B10T-I/SL's CLKOUT/BOOT pin can generate four selectable frequencies: 1 Hz, 4.096 kHz, 8.192 kHz, or 32.768 kHz - configured via RS2:RS0 bits (Control Register 0x08:2–0). Additionally, the MCP795B10T-I/SL asserts 32 kHz on this pin at power-up regardless of register settings, providing immediate clock availability before firmware initialization.