Microchip Releases New SPI Real-Time Clock
New, Battery-Backed RTCC Devices Include Faster, 10 MHz SPI Interface, Watchdog Timer, Event Detects and More Memory
Microchip have just announced a new family of stand-alone Real-Time Clock/Calendar (RTCC) devices. The MCP795WXX/BXX RTCC devices have a 10 MHz SPI interface, non-volatile memory and an effective combination of features at a price lower than most competitors' devices, including those with fewer features. The new devices reduce component counts and costs for applications in the smart-energy (e.g., thermostats, power meters and commercial refrigeration); home-appliance (e.g., coffee makers, stoves and microwave ovens); automotive (e.g., dashboard controls, car radios and GPS); consumer-electronic (e.g., office equipment and video systems); and communications markets (e.g., radios, cordless phones, and network systems), among others.

The MCP795WXX/BXX RTCC devices feature millisecond alarms and a 10 MHz SPI interface that supports very fast data access, resulting in longer MCU sleep and power-down modes, and less power draw from the battery. Other low-power features include two event-detect inputs that draw minimal current in the RTCC device, but wake the MCU when events such as a switch press or system tampering have occurred. Additionally, the devices include three types of non-volatile memory-EEPROM, SRAM and a Unique ID-which can be ordered blank or with a pre-programmed MAC address, as a standard product to further reduce component counts and lower costs associated with serialized programming. Along with the automatic battery switchover for backup power, a power-fail time stamp logs the time and duration of any power failure and, for accurate timekeeping over a broad temperature range, the devices feature a wide digital-trimming range that compensates for crystal frequency drift over temperature. In designs that need a low-frequency clock source, a boot-clock option in the RTCC can provide a 32 KHz clock output at power-up and eliminate the need for a second crystal.

“With our new SPI RTCC devices, we offer customers a high-quality timekeeping solution that also meets many of their other system requirements,” said Randy Drwinga, vice president of Microchip's Memory Products Division. “We made this possible by leveraging Microchip's core competencies and integrating an effective combination of features into a single device at a lower cost, which can be passed on to our customers.”
Features of the MCP795W10 Real Time Clock
- Low Power Operation Down to 1.8V
- Low Backup Power
- Automatic Battery Switchover On Power Loss with Timestamp
- Dual configurable alarms with a 0.01 sec count on one alarm
- Clock Out frequencies: 32.768, 8.192 & 4.096 KHz and 1 Hz
- Digital Trimming Range from -255 to + 255 ppm in 1 ppm steps
- Watchdog Timer - Dual Retriggers
- Dual Configurable Event Detects
- EEPROM has 8 Bytes/Page with Block Sector write protection
- Factory standard programming or custom ID available
More information on the MCP795W10 Real Time Clock and video presentation, can be found on the Microchip website at Microchip MCP795W10 product page
Note: The Microchip name and the Microchip logo are registered trademarks of Microchip Technology Incorporated in the U.S.A and other countries. All other trademarks mentioned herein are the property of their respective companies.
The Microchip website address is www.microchip.com
[Reprinted with kind permission from Microchip Corporation]