MCP79511-I/MS - SPI RTCC, 64B SRAM, 10-MSOP | Microchip
部品番号: MCP79511-I/MS ✓ 生産中| 数量 | 単価 | 小計 |
|---|---|---|
| 1 | $1.61 | $1.61 |
| 10 | $1.45 | $14.50 |
| 100 | $1.3 | $130.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $1.07 | $1,070.00 |
MCP79511-I/MS 概要
A Real-Time Clock (RTC) IC is a low-power timekeeping device that maintains accurate wall-clock time (seconds, minutes, hours, day, date, month, year) and calendar functions even when the main system is powered down. RTCs typically include a backup power input (battery or supercapacitor) to keep time during outages, and they communicate with a host microcontroller via serial interfaces such as I2C, SPI, or parallel buses. Within the broader hierarchy, an RTCC sits under Clock & Timing ICs -> Integrated Circuits, and shares architectural lineage with calendar/watchdog timers used in metering, data loggers, and secure element designs.
Key features of the MCP79511-I/MS include digital trimming for high-accuracy timekeeping (typically ±5 ppm across the industrial temperature range), automatic power-switchover to a backup battery when VCC drops below threshold, two configurable interrupt outputs for alarms and watchdog functions, and a unique pre-programmed 48-bit MAC address (EUI-48) that simplifies networking product compliance. The SPI interface operates at up to 5 MHz for fast register access and supports 1-byte to 64-byte block writes to the SRAM and EEPROM. The integrated 2 Kbit EEPROM provides ample storage for application parameters, configuration data, or tamper logs.
Architecturally, the MCP79511 uses a 32.768 kHz crystal oscillator input with an on-chip digital trimming DAC, allowing fine frequency adjustment to compensate for crystal tolerance and aging. The device's power-sense circuitry continuously monitors VCC and seamlessly switches to backup supply without losing time integrity, which is critical for metering, security, and IoT edge nodes. A separate backup-supply pin (VBAT) accepts 1.3V-3.6V, supporting lithium coin cells or supercapacitors.
Typical applications include smart energy metering (AMI), data loggers with timestamping, industrial automation controllers requiring scheduling, security alarm panels, IoT edge nodes with secure timekeeping, and any embedded system needing persistent date/time during power cycles. The pre-programmed EUI-48 MAC ID simplifies Wi-Fi, Ethernet, or 6LoWPAN commissioning and avoids the need for external MAC address storage.
When designing with the MCP79511-I/MS, place the 32.768 kHz crystal as close to the X1/X2 pins as possible and use load capacitors that match the crystal's specified load capacitance (typically 6-12.5 pF). Decouple VCC and VBAT with 100 nF ceramic capacitors to handle the automatic switchover transient and prevent register corruption.
This page synthesizes Microchip datasheet specifications, distributor pricing as of 2026-10-09, verified drop-in alternatives, and practical design notes not typically assembled on a single manufacturer datasheet page.
ドロップイン代替品: MCP79511-I/MS — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: MCP79511-I/MS （同一形状・フットプリント） — 相違点: Device Type, Interface, Package.
クイック比較ツール — 並列比較する代替部品を選択:
MCP79510-I/MS
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MCP79512-I/MS
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MCP79520-I/MS
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MCP79522-I/MS
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MCP79521-I/MS
✅ ドロップイン📋 参考代替品（カタログ未掲載）
MCP79511-I/MS 仕様
| Device Type | Real Time Clock (RTC) / Calendar |
| インターフェース | SPI (Serial Peripheral Interface) |
| Supply Voltage (VCC) | 1.8 V to 3.6 V |
| Backup Battery Voltage (VBAT) | 1.3 V to 3.6 V |
| 動作温度 | -40C to +85C (Industrial, 'I' grade) |
| Battery-Backed SRAM | 64 bytes |
| EEPROM Memory | 2 Kbit (256 bytes) |
| Unique ID | Pre-programmed EUI-48 MAC address |
| Crystal Frequency | 32.768 kHz (external) |
| Crystal Load Capacitance | 6 pF to 12.5 pF (typical) |
| Interrupt Outputs | 2 (MFP pins, configurable) |
| Power Switchover | Automatic VCC to VBAT, with trickle charger |
| パッケージ | 10-pin MSOP (3.0 mm width) |
| 実装タイプ | Surface Mount |
| MSLレベル | 1 |
| RoHS ステータス | Compliant |
MCP79511-I/MS ピン構成
| ピン 1 | SO — SPI Serial Data Output |
| ピン 2 | X1 — 32.768 kHz Crystal Input |
| ピン 3 | X2 — 32.768 kHz Crystal Output |
| ピン 4 | VBAT — Backup Battery Supply |
| ピン 5 | MFP2 — Multi-Function Pin 2 / Interrupt Output |
| ピン 6 | MFP1 — Multi-Function Pin 1 / Interrupt Output |
| ピン 7 | CS — SPI Chip Select (active low) |
| ピン 8 | SCK — SPI Serial Clock |
| ピン 9 | SI — SPI Serial Data Input |
| ピン 10 | VCC — Primary Power Supply |
主な用途
MCP79511-I/MS の用途: 6 件s: Smart Energy Metering, Data Logger with Timestamping, Security and Alarm Panels, Industrial Automation Controllers, IoT Edge Nodes and Wireless Sensors, Medical Monitoring Devices.
Smart Energy Metering
The MCP79511-I/MS fits smart energy meters by providing a battery-backed time reference that survives power outages and tampered line conditions. Its automatic VCC-to-VBAT switchover at the ~2.0V threshold keeps the clock accurate through brownout events, while the 64-byte SRAM retains tamper flags and the 2 Kbit EEPROM holds calibration constants and time-of-use (TOU) tariff schedules. The pre-programmed EUI-48 MAC ID eliminates the need for a separate MAC EEPROM on the meter's communication module, reducing BOM cost and PCB space. SPI runs at up to 5 MHz for fast host access during metrology reads, and the two MFP interrupts can trigger metrology sampling or alert the host to power-quality events. Industrial -40C to +85C operation matches outdoor meter enclosures.
おすすめ
Data Logger with Timestamping
Industrial data loggers for HVAC, refrigeration, and cold-chain monitoring benefit from the MCP79511-I/MS's persistent timekeeping across power cycles. The integrated 2 Kbit EEPROM stores up to 256 bytes of configuration parameters (sample rate, alarm thresholds, calibration offsets), while the 64-byte SRAM holds runtime counters and the most recent log buffer. Battery backup via VBAT ensures log continuity during sensor power interruptions, and the digital trimming function lets designers compensate for crystal aging over multi-year deployments. The two configurable MFP outputs can be programmed as watchdog alarms or event triggers, allowing the host microcontroller to wake only when a scheduled log interval elapses - extending battery life. The 10-MSOP package fits compact logger PCBs.
おすすめ
Security and Alarm Panels
Security panels require a real-time clock that survives both AC power loss and battery replacement, exactly what the MCP79511-I/MS provides. Its wide 1.3-3.6V VBAT range supports rechargeable backup batteries with a built-in trickle charger managed by the device, and the automatic switchover is fast enough to avoid missing time stamps on intrusion events. The pre-programmed EUI-48 MAC ID accelerates panel commissioning on IP-based central station reporting. Two MFP interrupts drive piezo buzzers or LED indicators, while the 2 Kbit EEPROM holds installer codes and zone descriptors. Industrial temperature rating supports unheated garages and outdoor panels. SPI access at 5 MHz allows fast arm/disarm operations during keypad entry.
おすすめ
Industrial Automation Controllers
PLC and industrial controller designs use the MCP79511-I/MS to provide deterministic timestamps for scheduled I/O, motion profiles, and event logging. The SPI interface at up to 5 MHz integrates with Microchip's PIC and dsPIC host families as well as ARM Cortex-M MCUs from other vendors, while the 10-MSOP footprint fits compact DIN-rail modules. The integrated 2 Kbit EEPROM stores controller configuration (network addresses, PID parameters) and the 64-byte SRAM holds scheduler scratchpad data. Automatic battery switchover with trickle charging keeps the clock running through plant-side power dips and brownouts common in industrial environments. The digital trimming function maintains <±5 ppm accuracy over the -40C to +85C industrial range.
おすすめ
IoT Edge Nodes and Wireless Sensors
Wi-Fi, LoRa, and 6LoWPAN edge nodes benefit from the MCP79511-I/MS because the pre-programmed EUI-48 MAC ID removes the need for external MAC storage, simplifying certification and reducing BOM cost. Battery-backed timekeeping via VBAT preserves timestamps during sleep cycles and across coin-cell replacements. The 64-byte SRAM buffers the latest sensor readings before host wake-up, and the 2 Kbit EEPROM holds network credentials, calibration data, and device descriptors. SPI runs at low MHz to keep active current small, while the two MFP interrupts can wake the host on alarm or scheduled sample events. The 10-MSOP footprint is small enough for coin-cell powered sensor nodes.
おすすめ
Medical Monitoring Devices
Patient monitors and medical data loggers use the MCP79511-I/MS to maintain audit-quality timestamps across power events and battery replacement cycles. The automatic VCC-to-VBAT switchover preserves log integrity, while the digital trimming ensures timekeeping accuracy required for compliance with healthcare standards. The 2 Kbit EEPROM stores patient ID, calibration data, and device configuration, and the 64-byte SRAM buffers the most recent measurements. SPI access allows fast retrieval during clinician review. The wide -40C to +85C operating range supports ambulance and field-hospital environments. The integrated EUI-48 MAC ID simplifies wireless bedside monitor deployments. Compact 10-MSOP package fits portable handheld devices.
おすすめ
おすすめ製品の概要
エンジニアリング参考データ: MCP79511-I/MS — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
代替品との比較
| パラメータ | この製品 | MCP79510-I/MS | MCP79512-I/MS | MCP79520-I/MS | MCP79522-I/MS | MCP79521-I/MS |
|---|---|---|---|---|---|---|
| Package | 10-MSOP | 10-MSOP - same | 10-MSOP - same | 10-MSOP - same | 10-MSOP - same | 10-MSOP - same |
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Unique ID | Pre-programmed EUI-48 | None | Pre-programmed EUI-64 | None | Pre-programmed EUI-64 | Pre-programmed EUI-48 |
| Battery-Backed SRAM | 64 bytes | 64 bytes | 64 bytes | 64 bytes | 64 bytes | 64 bytes |
| EEPROM Memory | 2 Kbit (256 bytes) | 2 Kbit | 2 Kbit | 2 Kbit | 1 Kbit | 1 Kbit |
| Supply Voltage VCC | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V | 1.8 V to 3.6 V |
| Interface | SPI | SPI | SPI | SPI | SPI | SPI |
| Operating Temperature | -40C to +85C (Industrial) | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C | -40C to +85C |
主な差別化要因
- Integrated pre-programmed EUI-48 MAC ID （vs MCP79510-I/MS)
- Higher integrated EEPROM density vs MCP79521/MCP79522 （vs MCP79521-I/MS)
- EUI-48 vs EUI-64 selection （vs MCP79512-I/MS)
設計ノート
Place the 32.768 kHz crystal as close as possible to the X1 and X2 pins (typically within 5 mm) to minimize parasitic capacitance and noise pickup. Route the crystal traces over a continuous ground plane and avoid running noisy digital signals (SPI, switching nodes) underneath the crystal traces. Decouple VCC with a 100 nF ceramic capacitor placed within 3 mm of the VCC pin, and place a 100 nF cap on VBAT as well to stabilize the backup supply during automatic switchover events.
The MCP79511-I/MS performs automatic switchover from VCC to VBAT when VCC drops below the power-fail threshold (~2.0V typical). To prevent register corruption during switchover, ensure that the bulk capacitor on VCC and the backup source on VBAT can both supply the device's minimum operating current until VCC recovers or the system shuts down cleanly. When using a supercapacitor on VBAT, enable the internal trickle charger via the appropriate register bits and limit charge current with an external resistor per the datasheet's recommended values.
Do not exceed VCC = 3.6V or VBAT = 3.6V - applying 5V to either pin will damage the device. When reading the EUI-48 MAC ID, use sequential SPI reads from the dedicated address range - do not assume the ID is contiguous in memory without consulting the register map in datasheet document 22265A. The MFP pins default to general-purpose outputs after power-up; configure them to the desired interrupt function before relying on alarm events. Do not leave the CS pin floating - it must be driven by the host to enable SPI communication.
コンプライアンス情報
RoHS and REACH compliant per Microchip product page. Not AEC-Q100 qualified - choose AEC-Q100 qualified RTCC variant for automotive designs. Lead-free and halogen-free packaging per MSL-1 rating.
