What is FRAM | Ferroelectric RAM Basics
This page covers Ferroelectric RAM basics.It mentions Ferroelectric RAM application note and Ferroelectric RAM manufacturers or Vendors.
FRAM is the short form of ferroelectric random access memory. This device combines the fast read/write access of dynamic RAM. It is non-volatile and have ultra low power consumption. As no ferrous material is used, the FRAM chip is not affected by any magnetic fields.
It is widely used in many applications such as medical equipment, automotive, instrumentation, RFID, microcontrollers, electronic metering etc. Moreover Ferroelectric RAM is useful for wearable devices. The revolution in IoT (Internet of Things) have made it possible to avail affordable wearable devices as much as possible.
As shown in the figure-1, FRAM memory cell made of capacitor connected to plate & bit line. The orientation of dipole within capacitor will determine whether "1" or "0" has been stored. The dipole orientation can be set and reversed by application of voltage across the either line.
Ferroelectric RAM Application Note
Ferroelectric RAM from fujitsu semiconductor has following specifications:
• Model No: MB85RS1MT
• Bit configuration: 131072 x 8 bits
• Supports SPI interface
• Frequency of operation: 1.8V-2.7V @ 25MHz, 2.7V-3.6V @ 30MHz
• Package type: 8 pin SOP with RoHS compliant
FRAM usually will be considered better compare to EEPROM and Flash memory types. Following table mentions difference between FRAM, EEPROM and Flash memory. Information mentioned in the table has been derived from research done on FRAM by Texas Instruments.
| Specifications | FRAM | EEPROM | Flash |
|---|---|---|---|
| time needed to write 64 bytes to the memory | 1.6 µS | 2200 µS | 6400 µS |
| time needed to read 64 bytes from the memory | 1.6 µS | 4.5 µS | 4.5 µS |
| number of write cycles supported | 100 trillion | 5 Lac | 1 Lac |
| voltage required to perform write operation | 1.5Volt | 10 to 14 Volt | 10 to 14 Volt |
| resistance to radiation of gamma type | yes | no | no |
Ferroelectric RAM Manufacturers/Vendors
Following are popular Ferroelectric RAM manufacturers/vendors:
• DigiKey
• Fujitsu
• Texas Instruments
• Ramtron International Corporation
• Cypress Semiconductor
• Celis Semiconductor