DS17885-3

DS17885-3 application field and working principle

The DS17885-3 Real Time Clock(RTCs) are designed specifically for applications where the archiving and the retrieval of the date and time information is a critical necessity.

Application Field of DS17885-3 RTC

The DS17885-3 is applicable in a wide range of applications including in desktop and notebook computers, embedded systems, routers, point-of-sale (POS) systems, digital music players, network appliances, and industrial and medical equipment. When used properly, the DS17885-3 eliminates the need for a separate microcontroller to control the date and time of a system.

Working Principle of DS17885-3 RTC

The DS17885-3 RTC module consists of an oscillator and comparator circuits, a counter, a timer circuit, and a series of registers that are used to store the date and time information. The counters are incrementally augmented upon any oscillator period. The crystal oscillator that serves as the basic rhythm is rated to 32khz and is accurate to ±3 ppm. This clock rate provides updates to the counter every second. The timer circuit provides a means for the device to constantly monitor time and trigger interrupts for various time-dependent events such as alarms.

As the basic unit of the device, the 8-bit counter circuits allow the device to achieve the high-accuracy time keeping. These counter circuits will increment per CPU cycle (1.2ms). The device also has a built-in “clock-out” feature that will allow an external circuit to have access to the periodic clock rate. This feature is typically used to control processes such as a serial transfer of date and time information.

The device has several registers and flags that control the functionality of the device. These registers and flags control the setting and retrieval of the date and time information, interrupt generation, and calibration and trimming of the oscillator clock rate. The DS17885-3 also has a set of “power management” settings that provide a means to reduce power consumption during standby periods.

Conclusion

The DS17885-3 Real Time Clock is a versatile, high-precision module with a wide range of applications. With features such as a 32KHz crystal oscillator, precise counters, and programmable settings, the DS17885-3 eliminates the need for a peripheral control unit. This device can handle time-critical information for applications in desktop and notebook computers, embedded systems, routers, point-of-sale (POS) systems, digital music players, and more.