Our FeRAM for rotary encoders (MB85RDP16LX) is equipped with an internal counter and FeRAM. This means that when used in a rotary encoder that counts the rotation speed of a motor, the fast start-up, high-speed writing, and low power consumption of the FeRAM itself are not affected. The calculation and writing of data stored in FeRAM is completed by the small amount of power generated by the coil's electromotive force, etc., so the number of motor revolutions can continue to be counted even without a power supply.
Reasons to Choose FeRAM for
Rotary Encoders
Five Reasons to Choose FeRAM for Rotary Encoders
1.Fast start-up speed
Unlike flash memory and other memory solutions, FeRAM does not require a boost power supply or complex internal power sequencing.
This means that there is no need to wait for the power supply to stabilize, and the memory can be accessed immediately after the power supply is turned on.
2.High-speed write and high rewrite endurance
Unlike EERPOM, FeRAM does not require a waiting time for write operations and is capable of a large number of rewrites, making it possible to perform data calculations in memory (i.e., in the FeRAM).
Since MB85RDP16LX is equipped with an internal counter processing calculation circuit, it is possible to perform counter calculation processing of data in memory and overwrite with calculated data without the need to read the previous data outside of memory.
3.Low power consumption
FeRAM does not require a boost power supply to write data, and the short write time means that it requires far less power (energy) than other types of non-volatile memory. This enables it to operate on weak power such as energy harvesting, and to operate for a long time, even in battery-powered systems.
4.Resistance to magnetic fields
MRAM is another type of non-volatile memory that can perform high-speed write operations similar to FeRAM. However, MRAM is vulnerable to magnetic fields because it stores bits of data (ones and zeroes) using magnetic field orientation, and it is therefore necessary to protect it with anti-magnetic shielding to prevent data from becoming corrupted.
It is not recommended to use MRAM in places where magnets are being used, especially around motors.
FeRAM is also used in space applications (space exploration, etc.) because it is highly resistant to magnetic and electric fields due to its memory cell structure, and is also resistant to software errors.
5.No battery required
Because FeRAM is non-volatile memory, it does not require a battery to store data, making it ideal for replacing battery-backed SRAM (BB-SRAM), which has similar specs and is used in a similar way.
By replacing BB-SRAM with FeRAM, batteries can be eliminated from the system, which is effective in terms of both protecting the environment and reducing maintenance costs.
- FeRAM with optimal specifications as non-volatile memory for rotary encoders
For the above reasons 1–5, MB85RDP16LX—which was developed as FeRAM for rotary encoders—can begin operation immediately after power start-up with an extremely short power supply time of 20-30μs, with power generated by the rotating magnets and coils inside the rotary encoder. It can also perform data calculations in memory, and shut down immediately after the calculation data is written.
Issue
The time for power supply by the coil electromotive force is only 20-30μs, which is extremely short. Write operations cannot be completed in such a short time with normal non-volatile memory.
Solution
This FeRAM product (MB85RDP16X) can correctly read previous data, update and save data after counter calculation, and shut down at any time, even in environments where only 20–30μs of pulsed power is supplied.
