Microchip Technology MCP79410-I/MS

Overview

MCP79410-I/MS from Microchip Technology is a battery-backed I²C Real-Time Clock/Calendar (RTCC) IC with integrated 64-byte SRAM, 1 Kbit EEPROM, and digital trimming capability. It maintains time across hours/minutes/seconds/day/month/year with leap-year compensation to 2399, operates from 1.8V–5.5V, draws just 1.2 µA at 3.3V, and supports alarm-triggered MFP output in industrial temperature range (−40°C to +85°C). It is used in smart meters, industrial HMIs, and backup-power-critical embedded systems.

For engineers reviewing the MCP79410-I/MS datasheet, MCP79410-I/MS pinout, MCP79410-I/MS application, or MCP79410-I/MS equivalent, key selection considerations include its ±1 ppm digital trim resolution, power-fail timestamp logging, dual programmable alarms, open-drain multifunction pin (MFP), and compatibility with 6–9 pF 32.768 kHz crystals - all validated for industrial-grade timekeeping reliability.

Technical Context

The MCP79410-I/MS implements a fully autonomous RTCC subsystem using an on-chip oscillator control loop with digital frequency trimming (±129 ppm range, ±1 ppm step), synchronized to an external 32.768 kHz crystal connected to X1/X2 pins. Its I²C interface complies with standard mode (100 kHz) and fast mode (400 kHz) timing, with SDA/SCL featuring Schmitt-trigger inputs and open-drain outputs requiring external pull-ups.

Power management includes automatic switchover between VCC (1.8–5.5 V) and VBAT (1.3–5.5 V) at VTRIP = 1.5 V (typ.), with dedicated power-fail timestamp registers capturing both switchover-to-battery and restore-from-battery events. The device retains RTC state and 64-byte SRAM during backup operation with IBATT = 925 nA at 3.0 V.

Key Specifications

Pinout & Package

The MCP79410-I/MS is housed in an 8-pin MSOP package (3.0 mm × 3.0 mm, 0.65 mm pitch) with exposed pad (optional VSS connection). All pins are surface-mount compatible and support reflow soldering per JEDEC J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCP79411-I/MS, the MCP79410-I/MS omits factory-programmed MAC addressing but offers identical timekeeping, alarm, and memory functionality at lower unit cost. Against DS3231M+, it trades ±2 ppm TCXO accuracy for superior low-power operation, richer alarm flexibility, and built-in timestamp logging - making it optimal for cost-sensitive, battery-constrained industrial designs.

Availability

MCP79410-I/MS is available at Aetrix Electronics and suitable for smart metering, industrial HMI, medical infusion pumps, and building automation controllers requiring stable component supply across extended production lifecycles.

Supply support for MCP79410-I/MS 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 MCP7941X product line was designed specifically for high-reliability, low-power real-time clock applications in industrial, medical, and energy infrastructure systems - emphasizing battery longevity, timestamp integrity, and field-programmable calibration.

FAQ

What is the primary function of the MCP79410-I/MS in a system?

The MCP79410-I/MS serves as a standalone Real-Time Clock/Calendar (RTCC) IC that maintains accurate time and date across power cycles using internal counters and a 32.768 kHz crystal. It provides battery-backed timekeeping, dual alarms, power-fail timestamp logging, and 64-byte SRAM - all accessible via I²C. The MCP79410-I/MS is not a microcontroller but a dedicated timing peripheral optimized for reliability and ultra-low power.

Does the MCP79410-I/MS require external load capacitors for the crystal?

Yes, the MCP79410-I/MS requires external load capacitors on X1 and X2 to match the specified load capacitance (CL) of the 32.768 kHz crystal - typically 6–9 pF. The device's oscillator is optimized for this CL range; mismatched capacitors cause frequency deviation or startup failure. Stray board capacitance must also be included in CL calculation per Equation 5-1 in the datasheet.

How does the power-fail timestamp feature work in the MCP79410-I/MS?

The MCP79410-I/MS automatically logs the exact time of VCC loss (power-down timestamp) and VCC restoration (power-up timestamp) into dedicated registers (0x18–0x1F). This occurs during switchover between VCC and VBAT supplies at ~1.5 V. Both timestamps are stored in BCD format and remain readable after power recovery - enabling forensic analysis of brownout events without host MCU intervention.

Can the MCP79410-I/MS operate solely from the VBAT supply?

Yes, the MCP79410-I/MS fully maintains RTC operation, SRAM contents, and alarm functionality while powered only by VBAT (1.3–5.5 V), drawing as little as 925 nA at 3.0 V. However, I²C communication and EEPROM writes are disabled during VBAT-only operation - only timekeeping, alarm assertion, and timestamp logging remain active.

What is the difference between MCP79410-I/MS and MCP79412-I/MS?

The MCP79412-I/MS is functionally identical to the MCP79410-I/MS but preprogrammed with an EUI-64™ address in its protected 64-bit EEPROM. The MCP79410-I/MS has unprogrammed protected EEPROM - allowing user-defined content. Pinout, timing, memory layout, and all electrical specifications are identical; only the factory-programmed identifier differs.