What is "RTC"?

"RTC" is an acronym for Real Time Clock, which is an electronic device that measures time.

What is "RTC Module"?

"RTC module" is a single packaged module which integrated RTC IC, oscillator circuit and master clock. There is no need for oscillator circuit design and frequency adjustment by yourselves.

Are You Struggling with These Problems? 3 Types of Issues Epson RTC Module Can Solve

1. Back up current consumption cannot meet specifications...

   The trend of a reduction of current consumption is getting stronger in many IoT applications.
   For a Smart Utility Meter, the tamper detect function is often required for security. However, if the microcontroller operates every time for the tamper detection, the system current consumption may be high. RTC can take over many of the house keeping functions at a much lower power.

2. Data retention of time information is too short with the back up battery...

   To keep the correct time information during a power failure is a requirement.
   Higher capacity battery may not be an option due to space constrains or cost.

3. Accuracy of clock gets worse under extreme temperature conditions...

   High accuracy clock needs is increasing for Smart Utility Meters. Power utility companies use time-base to charge customers.
   Smart Utility Meters are often exposed to extreme weather conditions, the RTC maintains a higher accuracy clock over the wide temperature range.
   For industrial applications, the high operation temperature is needed for the RTC module. That is due to highly elevated temperature inside the equipment.

Epson RTC Module Solves 3 Types of Issues

High accuracy and low power consumption RX8901CE and RX4901CE

It is a RTC module with enhanced features and operate under a wide temperature range (-40 to 105°C). RX8901CE supports I²C-Bus interface and RX4901CE supports SPI-Bus interface.

Main features of RX8901CE and RX4901CE

• Extended operations from a back-up battery

  Low current consumption (240nA Typ.)

• Record time stamps from up to 3 Types of sensors.

  Time stamps can be recorded up to 32 times and up to 3 inputs can be supported.

• High accuracy time information at elevated temperature condition (up to 105°C).

  With the D-TCXO function, it can provide high accuracy clock over a wide operating temperature range (-40 to 105°C)

• Versatility - Selection of interface (I²C/SPI) and multiple other functions

  Supports I²C-Bus or SPI-Bus interface standards. Also supports various configuration of multiple event pins, time stamps, and other functions

* Applications

- Utility Smart Meters
- Surveillance Security equipment
- Industrial factory automation / Industry 4.0

3 Reasons for Using RTC Module

1. Reduce standby power and lower system power

   The Time Stamp function stores the time information when an event (signal) is detected. The RTC module puts the MCU in a low power sleep state, thus reducing the power consumption of the entire system.

   Common circuit configuration

   

   Epson proposal

   

2. Power switch function for efficient use of backup power supply

   RTC module detects a voltage drop of the main power supply and automatically switches to a backup power supply for operation. while the MOS switch suppresses leakage current and voltage drops, enabling efficient power management of the entire system compared to diode OR circuits.

   

   

3. Provide High precision time information when the temperature changes

   DTCXO (Digital Temperature Compensated Xtal Oscillator) is installed in the RTC module. The RTC module provides highly accurate time information up to 105°C.