AN97044 Migrating from FM25V20 to FM25V20A Author: Girija V Chougala Associated Project: No Associated Part Family: FM25V20, FM25V20A Software Version: None Related Documents: For a complete list, click here AN97044 discusses the key differences that need to be considered when migrating from FM25V20 to FM25V20A. FM25V20 is now “Not Recommended for New Designs”; this application note explains how FM25V20A is a drop-in replacement for FM25V20. 1 Introduction FM25V20A, a 2-Mbit Serial (SPI) F-RAM, is a drop-in replacement device for FM25V20, which is now “Not recommended for new designs”. For all designs, the FM25V20A device can be considered as a superset of the FM25V20. The two devices are identical in terms of pinout, package composition and dimensions, and read/write functionality. This application note discusses the key differences between the two devices that need to be considered when migrating from FM25V20 to FM25V20A. 2 Drop-In Replacement or Not? From a hardware point of view, the two devices are identical. From a software point of view, they are identical except for the Device ID. Thus, FM25V20A is a drop-in replacement part for the FM25V20. Refer to the “Software Considerations” section for more details. Table 1 shows the compatibility chart of FM25V20 and FM25V20A. For a detailed comparison of the devices, see Table 3. Table 1. Compatibility Chart FM25V20 Feature or Spec Is FM25V20A compatible? Package Yes Pinout Yes Temperature Range Yes Operating Voltage Yes Operating Current Yes Standby Current Yes Read / Write Function Yes Timing / Frequency Yes Data Retention Yes Endurance Yes www.cypress.com Document No. 001-97044 Rev. *A 1 Migrating from FM25V20 to FM25V20A 3 Ordering Part Numbers Table 2 gives the recommended FM25V20A ordering part numbers that correspond to the FM25V20 (Not Recommended for New Designs) ordering part numbers. Table 2. Recommended Ordering Part Numbers for Migration FM25V20 Ordering Part Number FM25V20-G FM25V20-GTR 4 FM25V20A Status Ordering Part Number Not Recommended for New Designs FM25V20A-G In Production No hardware change required Software change required for Device ID update only FM25V20A-GTR FM25V20-DG FM25V20A-DG FM25V20-DGTR FM25V20A-DGTR Comments Status Detailed Comparison of FM25V20 and FM25V20A Table 3 gives a detailed comparison of the two devices. Table 3. Detailed Comparison Table FM25V20 FM25V20A -G, -DG -G, -DG Pinout/package Outline SOIC-8, TDFN-8 SOIC-8, TDFN-8 Identical pinout, outline and board footprint. Temperature Range –40 ºC to +85 ºC –40 ºC to +85 ºC Identical Identical Package type Operating Voltage Range Comments Identical “green (RoHS)” packages. 2.0 V to 3.6 V 2.0 V to 3.6 V 300 µA @ 1 MHz 300 µA @ 1 MHz 3.0 mA @ 40 MHz 3.0 mA @ 40 MHz 250 µA @ 85 ºC 250 µA @ 85 ºC Identical 8 µA 8 µA Identical 2-byte addressing, op-codes 2-byte addressing, opcodes Identical 40 MHz 40 MHz Identical 10 years (+85 ºC) 10 years (+85 ºC) Identical 1E+14 1E+14 Identical VDD Power-Up Ramp Rate (tVR) 50 µs / V 50 µs / V Identical VDD Power-Down Ramp Rate (tVF) 100 µs / V 100 µs / V Identical 1 ms 1 ms Identical 7F7F7F7F7F7FC22500h 7F7F7F7F7F7FC22508h Active Supply Current Standby Current Sleep Mode Current Read / Write Function Clock Frequency Data Retention Endurance (Write/Read Cycles) Power-Up to First Access (tPU) Device ID www.cypress.com Document No. 001-97044 Rev. *A Identical Different. Refer to Device ID section in “Software Considerations” for more details. 2 Migrating from FM25V20 to FM25V20A 5 Software Considerations This section discusses the Device ID difference between FM25V20 and FM25V20A. A system software update is required if the existing application uses the Device ID feature of FM25V20. 5.1 Device ID The FM25V20 and FM25V20A incorporate a 9-byte read-only Device ID to identify the product uniquely. The Device ID allows the host to determine the manufacturer, product density, and product revision. Table 4 gives the Device IDs of FM25V20 and FM25V20A, where the difference is highlighted in red. Table 4. Device ID Device ID 6 FM25V20 FM25V20A 7F7F7F7F7F7FC22500h 7F7F7F7F7F7FC22508h Summary AN97044 discussed the differences between FM25V20 and FM25V20A that need to be considered during migration to the FM25V20A. 7 Related Documents Datasheets FM25V20: 2-Mbit (256 K × 8) Serial (SPI) F-RAM datasheet FM25V20A: 2-Mbit (256 K × 8) Serial (SPI) F-RAM datasheet Application Note AN304 – SPI Guide for F-RAM www.cypress.com Document No. 001-97044 Rev. *A 3 Migrating from FM25V20 to FM25V20A Document History Document Title: AN97044 – Migrating from FM25V20 to FM25V20A Document Number: 001-97044 Revision ECN Orig. of Change Submission Date Description of Change ** 4737610 GVCH 04/28/2015 New Application Note *A 4771733 GVCH 05/20/2015 Corrected a typo in the part number www.cypress.com Document No. 001-97044 Rev. *A 4 Migrating from FM25V20 to FM25V20A Worldwide Sales and Design Support Cypress maintains a worldwide network of offices, solution centers, manufacturer’s representatives, and distributors. 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Disclaimer: CYPRESS MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARD TO THIS MATERIAL, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cypress reserves the right to make changes without further notice to the materials described herein. Cypress does not assume any liability arising out of the application or use of any product or circuit described herein. Cypress does not authorize its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress’ product in a life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress against all charges. Use may be limited by and subject to the applicable Cypress software license agreement. www.cypress.com Document No. 001-97044 Rev. *A 5