Introduction

At Bitfoic we offer the widest breadth of product in the electronics industry. Our product  includes tIntegrated Circuits (ICs),RF/IF and RFID,oscillators, Optics

, real time clocks (RTC), and miniature shielded power inductors. ECS Inc. is a recognized industry in electronic components products. Our products are widely used in IoT, wearables, consumer products, automotive electronics, and medical products.

1 What is Real Time Clocks?

A real time clock, or RTC, is a digital clock with a primary function to keep accurate track of time even when a power supply is turned off or a device is placed in low power mode. RTC’s are comprised of a controller, oscillator, and an embedded quartz crystal resonator. They are engineered as all-in-one devices to provide better performances than discrete components, simplify integration in new designs, and accelerate time to market.

RTCs are used in a variety of applications where they play a critical role in keeping accurate track of the current time while also providing alarms, timers, and interrupt functions and helping to reduce power consumption.

2 How does a real time clock module work?

An RTC maintains its clock by counting the cycles of an oscillator – usually an external 32.768kHz crystal oscillator circuit, an internal capacitor based oscillator, or even an embedded quartz crystal. Some can detect transitions and count the periodicity of an input that may be connected.

For Example,DS12C887 is a commonly used RTC. It can be easily interfaced with 8051 microcontroller (AT89C51). To explore the basic operation of accessing the internal registers and extracting time from the RTC, refer interfacing RTC DS12C887 with AT89C51.

3 Where is the real time clock?

RTCs can be found running in personal computers, embedded systems and servers, and are present in any electronic device that may require accurate time keeping. Being able to still function even when the computer is powered down through a battery or independently from the system's main power is fundamental. 

4 Why do we need real time clock?

The purpose of an RTC or a real time clock is to provide precise time and date which can be used for various applications. RTC is an electronic device in the form of an Integrated Chip (IC) available in various packaging options. It is powered by an internal lithium battery.

5 How long an RTC battery can be Used?

An RTC battery should last for three to five years or more. RTCs are essential; if the battery fails, it must be replaced to ensure continued operation. A dead battery can be diagnosed with an error message at startup or if the user finds that the clock or the setup configuration has become corrupted, flaky or odd.

6 What is the Benefits of RTCs?

• RTC ICs have proved to be more precise than other methods — like programming the timer of the controller.
• It frees the main system from time-critical tasks.
• It has low power consumption and improved frequency stability.

7 How RTCs are used today?

Many of today’s products are powered by batteries and have limited or no access to battery replacements or recharging power sources. Because of the lack of power sources, having all systems and sensor functions running continuously would quickly drain the battery of these devices. The solution is to have scheduled intermittent activation of the product to greatly extend the life of the battery. The use of a RTC allows the designer to power down the high current usage microcontroller when no task is required, resulting in significant power savings. When microcontrollers are in a deep sleep or low-power mode, the RTCs internal clock and circuitry will keep running to maintain accurate timekeeping and alarm functions. In this mode, the current draw will be as low as 0.5uA.