MCP79400-I/SN Microchip Integrated Circuit (Small Outline Packages) In Stock
The MCP79400-I/SN is a real-time clock (RTC) IC from Microchip in an 8-pin SOIC package, featuring I2C serial interface at up to 32 kHz clock frequency, 64 bytes of on-chip battery-backed SRAM, and interrupt output capability. It maintains accurate timekeeping in embedded systems including data loggers, home automation controllers, and industrial timer modules.
- Manufacturer
- Microchip
- Package
- Small Outline Packages
- Pin Count
- 8
- Lifecycle
- ACTIVE
- Datasheet
- MCP79400-I/SN Datasheet PDF
- Category
- Integrated Circuit
- Temp Range
- -40.0°C to 85.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- I2C serial interface up to 32 kHz clock
- 64 bytes battery-backed on-chip SRAM
- Interrupt output for alarm and periodic events
- 8-pin SOIC package for easy hand or SMT assembly
- Low power consumption for coin-cell backup operation
- Timekeeping with seconds, minutes, hours, date, month, year
Applications
The MCP79400-I/SN is suited for data logging and event-recording instruments where accurate timestamps must be maintained through power cycles using a coin-cell battery backup. It is also used in smart home controllers, industrial PLCs, and medical monitoring devices that require periodic alarm interrupts to wake a host microcontroller from sleep without a dedicated timer peripheral.
Specifications
| Manufacturer Package Code | SOIC-8 |
| Factory Lead Time | 6Weeks |
| YTEOL | 13 |
| Clock Frequency-Max | 0.032MHz |
| Information Access Method | SERIAL(I2C) |
| Interrupt Capability | Y |
| JESD-30 Code | R-PDSO-G8 |
| JESD-609 Code | e3 |
| On Chip Data RAM Width | 8 |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | SOP8,.23 |
| Package Shape | RECTANGULAR |
| Package Style | SMALL OUTLINE |
| Peak Reflow Temperature (Cel) | 260 |
| Qualification Status | Not Qualified |
| RAM (words) | 64 |
| Screening Level | TS 16949 |
| Supply Current-Max | 3mA |
| Supply Voltage-Max | 5.5V |
| Supply Voltage-Min | 1.8V |
| Supply Voltage-Nom | 2.5V |
| Surface Mount | YES |
| Technology | CMOS |
| Temperature Grade | INDUSTRIAL |
| Terminal Finish | Matte Tin (Sn) |
| Terminal Form | GULL WING |
| Terminal Pitch | 1.27mm |
| Terminal Position | DUAL |
| Time-Min | SECONDS |
| Volatile | NO |
| uPs/uCs/Peripheral ICs Type | TIMER, REAL TIME CLOCK |
| Package | Small Outline Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| Moisture Sensitivity Level | MSL 1 |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.01 |
| Country of Origin | Thailand |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for MCP79400-I/SN:
Frequently Asked Questions
How much on-chip memory does the MCP79400-I/SN provide for user data storage?
The MCP79400-I/SN includes 64 bytes of general-purpose SRAM that remains powered from the battery backup supply when the main VCC is removed, making it useful for storing calibration offsets, device configuration, or the last recorded measurement value so that data survives through a power outage without requiring external EEPROM.
How does the interrupt output of the MCP79400-I/SN reduce microcontroller power consumption in battery designs?
By generating a periodic interrupt or alarm output at a programmed interval, the MCP79400-I/SN allows the host microcontroller to remain in deep sleep mode drawing less than 10 µA, waking only when the RTC asserts the interrupt pin. This approach significantly extends battery runtime in data loggers and remote sensors compared to software-based periodic wake-up timers.
What I2C clock frequency does the MCP79400-I/SN support and how is it addressed on a shared bus?
The MCP79400-I/SN operates with I2C clock frequencies up to 32 kHz (32,768 Hz standard crystal rate) and uses a fixed 7-bit I2C device address, allowing it to share the same 2-wire bus with other I2C peripherals such as sensors, EEPROMs, and display controllers without additional address configuration pins in most single-device scenarios.
What are the key differences between the MCP79400-I/SN and adding a software-only RTC to a microcontroller?
Unlike software RTC implementations that lose time whenever power is removed or the MCU resets, the MCP79400-I/SN maintains accurate time from a 32.768 kHz crystal across power interruptions using its battery backup input, preserving timekeeping to within ±2 ppm accuracy in temperature-compensated variants over a -40°C to +85°C range without any firmware overhead.
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