The DS2417 is a real-time clock chip that features an interrupt function and is compatible with the 1-Wire MicroC interface from Dallas Semiconductor. It supports a serial communication rate of 16.3 kbps, and the interrupt interval can be programmed to suit different application needs. The chip uses a 32-bit binary-second counter to track time at a standard temperature of 25°C. When operating within an accuracy of ±2 minutes per month, it can be powered by a voltage range of 2.5V to 5.5V. Its power consumption is extremely low, only sinking 200nA, making it ideal for battery-powered applications. The DS2417 can be used in parallel with multiple DS2417 chips or other 1-Wire devices via the MicroLAN interface. This allows a single microprocessor port to communicate with numerous devices, reducing the number of required I/O pins and simplifying the overall circuit design.
Figure 1 shows the pinout of the DS2417, which comes in a 6-pin TSOC package. Table 1 outlines the functions of each pin. The internal architecture of the DS2417 includes a 64-bit ROM with a factory-programmed serial number, acting as the unique address for the device on the 1-Wire bus. The ROM structure consists of 8 bits for the product type (27H), 48 bits for the device's unique serial number, and 8 bits for a cyclic redundancy check (CRC) calculated using the polynomial X8 + X5 + X4 + 1. This ensures that each 1-Wire device has a distinct address, enabling multi-device communication on a single bus.
For the 1-Wire port, the clock reading and writing functions are separate from the ROM functionality. To access the clock functions, the bus controller must first send one of four ROM commands: Read ROM (33H), Match ROM (55H), Search ROM (F0H), or Skip ROM (CC H). These commands allow the system to target specific devices when performing read or write operations on the clock registers (66H for read, 99H for write). All data and commands are transmitted and received starting from the least significant bit.
The 5th and 6th pins of the DS2417 are connected to a 32.768MHz crystal oscillator. The internal oscillator and divider generate a 1Hz time reference signal, which is then used to drive the 32-bit binary real-time clock counter. The time count value is double-buffered, ensuring that read and write operations do not interfere with the ongoing time updates, thus preventing errors.
Since the DS2417 uses a 32-bit binary-second counter, its maximum overflow time is approximately 136 years. To use it effectively, a reference point must be defined, such as setting all 32 bits to zero as representing 0:00 on January 1, 2000. From this reference, the system can program the device to retrieve time information like seconds, minutes, hours, days, months, and years. However, if complex calendar functions are needed, the DS2417 may not be the best choice, and a dedicated calendar-based RTC chip would be more suitable.
After the system is powered down, the DS2417 will stop functioning. However, if a backup power source is connected to the VDD terminal, the chip can maintain its timekeeping function continuously, acting as a non-volatile real-time clock. This makes it ideal for applications where accurate time tracking is essential even during power interruptions.
circular connector,m series connector,m connector,m12 connector,m8 connector,circular connector m12,m8 electrical connector
Dongguan Yiyou Electronic Technology Co., Ltd. , https://www.dsubminiature.com