AN326 Migrating from Grade 1 version of FM25CL64 to Grade 1 version of FM25CL64B Author: Girija Chougala Associated Project: No Associated Part Family: FM25CL64-GA, FM25CL64B-GA Software Version: None Related Documents: For a complete list, click here AN326 discusses the key differences that need to be considered when migrating from Grade 1 version of FM25CL64 to Grade 1 version of FM25CL64B. FM25CL64 is now obsolete and this application note explains how FM25CL64B is a replacement for FM25CL64. Table 1. Compatibility Chart Introduction FM25CL64B-GA, a 64-Kbit SPI Grade 1 F-RAM™, is a replacement device for FM25CL64-GA, which is now obsolete. The two devices are identical in terms of package, pinout, DC / AC parameters, and read / write functionality. This application note discusses the key differences between the two devices that need to be considered when migrating from FM25CL64-GA to FM25CL64B-GA. FM25CL64-GA Feature or Spec Is FM25CL64B-GA compatible Package Yes Pinout Yes Temperature Range Yes Operating Voltage Yes Drop-In Replacement or Not? Operating Current Yes From a software point of view, the two devices are identical. Both the devices are read/write compatible and use the same two-byte address. From a hardware point of view, the key difference between the two devices is the FM25CL64B-GA’s lower operating current and higher standby current. Additionally, FM25CL64B-GA datasheet adds a power-up ramp rate, power-down ramp rate and first-access time specification. Standby Current No R/W Function Yes Timing/Freq Yes Data Retention Yes Endurance Yes Table 1 shows the compatibility chart of FM25CL64-GA and FM25CL64B-GA. For a detailed comparison, see Table 3. Ordering Part Numbers Table 2 gives the recommended FM25CL64B-GA ordering part numbers that correspond to the now obsolete FM25CL64-GA ordering part numbers. Table 2. Recommended Ordering Part Numbers for Migration FM25CL64-GA Ordering Part Number FM25CL64-GA FM25CL64-GATR www.cypress.com FM25CL64B-GA Status Obsolete Ordering Part Number FM25CL64B-GA Comments Status In production FM25CL64B-GATR Document No. 001-86849 Rev. *B No hardware or software change is required 1 Migrating from Grade 1 version of FM25CL64 to Grade 1 version of FM25CL64B Comparison of FM25CL64 and FM25CL64B Table 3 gives a detailed comparison of the two devices. Table 3. Detailed Comparison Package Types Package Outlines Pinout Temperature Range Operating Voltage Range Active Supply Current FM25CL64-GA FM25CL64B-GA -GA -GA SOIC-8 SOIC-8 - - Identical –40 ºC to +125 ºC –40 ºC to +125 ºC Identical 3.0 V to 3.6 V 3.0 V to 3.6 V Identical 450 µA @ 1 MHz 300 µA @ 1 MHz 7.0 mA @ 16 MHz 3.0 mA @ 16 MHz Comments Identical “green” SOIC package Identical outline and board footprint FM25CL64B-GA offers lower active current. 1 µA (+85 ºC) 6 µA (+85 ºC) 15 µA (+125 ºC) 20 µA (+125 ºC) - - 16 MHz 16 MHz - - 9000 hrs (+125 ºC) 11000 hrs (+125 ºC) after 11 yrs (+105 ºC) 17 yrs (+55 ºC) 121 yrs (+85 ºC) Unlimited 1E+13 FM25CL64B-GA’s endurance is large enough to be considered as unlimited for all practical applications. For a 64-byte loop, at 10 MHz, FM25CL64B-GA’s endurance is 17 years. VDD Power-Up Ramp Rate (tVR) - 30 µs / V Power-up ramp rate should be slower than 30 µs / V for FM25CL64B-GA VDD Power-Down Ramp Rate (tVF) - 20 µs / V Power-down ramp rate should be slower than 20 µs / V for FM25CL64B-GA Power-Up to First Access (tPU) - 1 ms Standby Current Read / Write Function Clock Frequency AC Timing Parameters Data Retention Endurance (Write/Read Cycles) FM25CL64B-GA has higher standby current Identical 2-byte addressing, Identical op-codes Identical All specification limits are the Identical FM25CL64B-GA offers better data retention After power-up, the first access FM25CL64B-GA should be after 1 ms of Critical Considerations You should consider all the parameter differences mentioned in Table 3 during the migration to FM25CL64B-GA. This section discusses the critical differences. System designers should also review the datasheet when migrating to the new part. VDD Ramp Rate VDD power-up and power-down ramp rate specifications are added in FM25CL64B-GA device. Ensure that the power-up ramp rate is slower than 30 µs / V and power-down ramp rate is slower than 20 µs / V in your system. Power-Up to First Access Power-up to first access specification is added in FM25CL64B-GA device. Ensure that the FM25CL64B-GA device is accessed only after 1 ms from power-up. Summary AN326 discussed the differences between the Grade 1 versions of FM25CL64 and FM25CL64B that need to be considered during migration to the FM25CL64B. www.cypress.com Document No. 001-86849 Rev. *B 2 Migrating from Grade 1 version of FM25CL64 to Grade 1 version of FM25CL64B Related Documents Datasheet FM25CL64B: 64-Kbit (8 K × 8) Serial (SPI) Automotive F-RAM datasheet Application Note AN304 – SPI GUIDE FOR F-RAM www.cypress.com Document No. 001-86849 Rev. *B 3 Migrating from Grade 1 version of FM25CL64 to Grade 1 version of FM25CL64B Document History Document Title: Migrating from Grade 1 version of FM25CL64 to Grade 1 version of FM25CL64B - AN326 Document Number: 001-86849 Revision ECN Orig. of Change Submission Date Description of Change ** 3944550 GVCH 03/26/2013 New Spec. *A 4279208 MEDU 03/05/2014 Updated to Cypress Template. Updated data retention for FM25640B-GA. Updated “VDD Power-Down Ramp Rate” for FM25CL64B-GA from 100 µs / V to 20 µs / V. Updated “Power-Up to First Access” for FM25CL64B-GA from 10 ms to 1 ms. *B 4498656 GVCH 09/23/2014 Changed title from “Differences between Grade 1 versions of FM25CL64 and FM25CL64B” to “Migrating from Grade 1 version of FM25CL64 to Grade 1 version of FM25CL64B.” Updated abstract. Added “Ordering Part Numbers” section. Added title for Table 3. Added “Related Documents” section. www.cypress.com Document No. 001-86849 Rev. *B 4 Migrating from Grade 1 version of FM25CL64 to Grade 1 version of FM25CL64B Worldwide Sales and Design Support Cypress maintains a worldwide network of offices, solution centers, manufacturer’s representatives, and distributors. To find the office closest to you, visit us at Cypress Locations. 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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. 001-86849 Rev. *B 5