Microchip Technology MCP795B11T-I/SL

Overview

MCP795B11T-I/SL from Microchip Technology is a SPI real-time clock/calendar (RTCC) IC with integrated 32 kHz boot-up clock, 64-byte battery-backed SRAM, 1 Kbit EEPROM, EUI-48™ unique ID, and dual programmable alarms. It operates from 1.8V to 5.5V VCC and 1.3V to 5.5V VBAT, supports digital trimming (±255 ppm), and delivers <700 nA timekeeping current at 1.8V - used in industrial metering, backup power logging, and embedded systems requiring precise timestamping during power loss.

For engineers reviewing the MCP795B11T-I/SL datasheet, MCP795B11T-I/SL pinout, MCP795B11T-I/SL application, or MCP795B11T-I/SL equivalent, key selection criteria include 32 kHz boot-up capability, VBAT switchover time-stamping, SPI interface timing compliance up to 10 MHz, and EUI-48™ MAC address availability for device identity management.

Technical Context

The MCP795B11T-I/SL implements a crystal-based RTCC with automatic oscillator start on power-up and hardware-supported 32 kHz CLKOUT/BOOT output using the same 32.768 kHz tuning fork crystal. 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 dedicated watchdog timer with configurable pulse duration (via Address 0x0A:4), open-drain WDO output (10 mA sink), and interrupt-driven alarm handling via shared IRQ pin. The device uses BCD-encoded time registers (0x00–0x1F), supports 12-/24-hour format with leap-year correction, and provides power-fail time-stamp logging in dedicated registers (0x18–0x1F).

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 MCP795W11T-I/SL, the MCP795B11T-I/SL adds guaranteed 32 kHz boot-clock output and eliminates startup delay in time-critical logging; versus DS3231M+, it trades ±2 ppm TCXO accuracy for integrated event detection, EUI-48™ identity, and lower VBAT current - making it optimal for cost-sensitive, feature-rich embedded systems with moderate accuracy needs.

Availability

MCP795B11T-I/SL is available at Aetrix Electronics and suitable for smart metering, industrial HMI, IoT gateways, and medical diagnostics requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MCP795B11T-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 microcontroller, mixed-signal, analog, and Flash-IP solutions, serving automotive, industrial, consumer, and communications markets with vertically integrated silicon and development tools.

The MCP795XXX product line was designed for embedded systems requiring autonomous, low-power timekeeping with integrated memory, event detection, and robust power-fail resilience - targeting metering, control, and networked edge devices.

FAQ

What is the primary function of the MCP795B11T-I/SL?

The MCP795B11T-I/SL is a SPI real-time clock/calendar IC that maintains accurate time and date across power cycles using a 32.768 kHz crystal, with integrated 64-byte battery-backed SRAM, 1 Kbit EEPROM, EUI-48™ unique ID, and dual programmable alarms. Its defining feature is the 32 kHz boot-up clock on the CLKOUT/BOOT pin, ensuring immediate timekeeping upon power application - a capability absent in the MCP795WXX series.

Does the MCP795B11T-I/SL require external components to operate?

Yes, the MCP795B11T-I/SL requires an external 32.768 kHz tuning fork crystal connected between X1 and X2 pins, two load capacitors (typically 12.5 pF each), and external pull-up resistors on WDO and IRQ pins (to VCC or VBAT). No external trim capacitors are needed due to on-chip digital calibration (±255 ppm in 1 ppm steps), and the 32 kHz boot-up clock eliminates reliance on MCU initialization delays.

How does the MCP795B11T-I/SL handle power failure and recovery?

The MCP795B11T-I/SL automatically switches from VCC to VBAT when VCC drops below 1.3–1.7 V, preserving RTC registers and SRAM contents. Crucially, it logs the exact time of VCC failure and restoration in dedicated power-down/power-up timestamp registers (0x18–0x1F), enabling precise outage duration tracking without MCU intervention - a feature confirmed in the DS22280A datasheet Section 1.0 and Figure 1-1.

What is the significance of the EUI-48™ unique ID in the MCP795B11T-I/SL?

The EUI-48™ unique ID is a factory-programmed 128-bit identifier stored in protected EEPROM space, providing a globally unique MAC address for networked device identification. This enables secure firmware binding, device authentication, and audit-log traceability in IoT gateways and medical equipment - eliminating the need for external ID storage or manufacturing-line programming, as specified in the Device Selection Table and Section 1.0 of DS22280A.

Can the MCP795B11T-I/SL generate multiple clock frequencies on its CLKOUT/BOOT pin?

Yes, the MCP795B11T-I/SL 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 delivers a fixed 32 kHz boot-up clock on the same pin at power-on (MCP795BXX-specific), independent of register settings. This dual-mode operation is documented in Section 1.0 (Clock Out Function) and Register 5-9 (Control Reg 0x08) of DS22280A.