AN317 Migrating from FM25L04 to FM25L04B Author: Girija Chougala Associated Project: No Associated Part Family: FM25L04, FM25L04B Software Version: None Related Documents: For a complete list, click here AN317 discusses the key differences that need to be considered when migrating from FM25L04 to FM25L04B. FM25L04 is now obsolete and this application note explains how FM25L04B is a replacement for FM25L04. Table 1. Compatibility Chart Introduction FM25L04B, a 4-Kbit SPI F-RAM™, is a replacement device for the FM25L04, which is now obsolete. The two devices are identical in terms of pinouts and read / write functionality. In terms of speed, FM25L04 operates up to 14 MHz and FM25L04B operates up to 20 MHz. This application note discusses the key differences between the two devices that need to be considered when migrating from FM25L04 to FM25L04B. FM25L04 Feature or Spec Is FM25L04B compatible? Yes (SOIC) Package No (TDFN) 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. The two devices are read/write compatible. Both devices use the same one-byte address. From a hardware point of view the key differences are the higher standby current of the FM25L04B and the TDFN package dimensions. Standby Current No Read / Write Function Yes Timing / Frequency Yes Data Retention Refer to Table 3 Endurance Table 1 shows the compatibility chart of FM25L04 and FM25L04B. For a detailed comparison, see Table 3. Yes Ordering Part Numbers Table 2 gives the recommended FM25L04B ordering part numbers that correspond to the now obsolete FM25L04 ordering part numbers. Table 2. Recommended Ordering Part Numbers for Migration FM25L04 Ordering Part Number FM25L04-G FM25L04B Status Obsolete Ordering Part Number FM25L04B -G FM25L04-GTR FM25L04B -GTR FM25L04-DG FM25L04B -DG FM25L04-DGTR FM25L04B -DGTR www.cypress.com Comments Status In production Document No. 001-86840 Rev. *B No hardware or software change is required No software change. Hardware change is required . 1 Migrating from FM25L04 to FM25L04B Comparison of FM25L04 and FM25L04B 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 Standby Current Read / Write Function Clock Frequency FM25L04 FM25L04B Comments -G, -DG -G, -DG Identical “green” SOIC package but different “Green” TDFN package Identical outlines and board footprints for SOIC but different for TDFN SOIC-8, SOIC-8, TDFN-8 (3 mm x 6.4 mm) TDFN-8 (4 mm x 4.5 mm) - - Identical –40 ºC to +85 ºC –40 ºC to +85 ºC Identical 2.7 V to 3.6 V 2.7 V to 3.6 V Identical 170 µA @ 1 MHz 200 µA @ 1 MHz 3.0 mA @ 14 MHz 3.0 mA @ 20 MHz 1 µA 6 µA (max) 3 µA (typical) - - 14 MHz 20 MHz FM25L04B current has higher standby Identical 1-byte addressing, Identical op-codes Improved speed in FM25L04B 10 years (+85 ºC) Data Retention 45 years (+85 ºC) 38 years (+75 ºC) Data retention is lower 151 years (+65 ºC) Endurance (Write/Read Cycles) Unlimited 1E+14 FM25L04B is virtually unlimited at 20 MHz (85 years for a 64-byte loop) VDD Power-Up Ramp Rate (tVR) 50 µs / V 30 µs / V Improved power-up ramp rate in FM25L04B VDD Power-Down Ramp Rate (tVF) 100 µs / V 30 µs / V Improved power-down ramp rate in FM25L04B - 1 ms After power-up, the first access of FM25L04B should be after 1 ms Power-Up to First Access (tPU) Critical Considerations You should consider all the parameter differences mentioned in Table 3 during the migration to FM25L04B. This section discusses the critical differences. System designers should also review the datasheet when migrating to the new part. Package Outline Both FM25L04 and FM25L04B devices are offered in SOIC and TDFN packages. While the SOIC package dimensions are the same, there is a difference in TDFN package dimensions. The package dimensions of FM25L04 are 3 mm x 6.4 mm and that of FM25L04B are 4 mm x 4.5 mm. Power-Up to First Access Power-up to first access specification is added in FM25L04B device. Ensure that the FM25L04B device is accessed only after 1 ms from power-up. www.cypress.com Document No. 001-86840 Rev. *B 2 Migrating from FM25L04 to FM25L04B Summary AN317 discussed the differences between FM25L04 and FM25L04B that need to be considered during replacement to the FM25L04B. Related Documents Datasheet FM25L04B: 4-Kbit (512 × 8) Serial (SPI) F-RAM datasheet Application Note AN304 – SPI GUIDE FOR F-RAM www.cypress.com Document No. 001-86840 Rev. *B 3 Migrating from FM25L04 to FM25L04B Document History Document Title: Migrating from FM25L04 to FM25L04B - AN317 Document Number: 001-86840 Revision ECN Orig. of Change Submission Date Description of Change ** 3944550 GVCH 03/26/2013 New Spec. *A 4279018 MEDU 02/12/2014 Updated to Cypress Template. Updated max operating range from 3.65 V to 3.6 V. Updated clock frequency for FM25L04 from 20 MHz to 14 MHz. Updated “VDD Power-Down Ramp Rate” for FM25L04B from 100 µs / V to 30 µs / V. Updated “Power-Up to First Access” for FM25L04B from 10 ms to 1 ms. *B 4498653 GVCH 09/22/2014 Changed title from “Differences between FM25L04 and FM25L04B” to “Migrating from FM25L04 to FM25L04B.” Updated abstract. Added “Ordering Part Numbers” section. Added title for Table 3. Added “Related Documents” section. www.cypress.com Document No. 001-86840 Rev. *B 4 Migrating from FM25L04 to FM25L04B 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. PSoC® Solutions Products Automotive cypress.com/go/automotive psoc.cypress.com/solutions Clocks & Buffers cypress.com/go/clocks PSoC 1 | PSoC 3 | PSoC 4 | PSoC 5LP Interface cypress.com/go/interface Lighting & Power Control cypress.com/go/powerpsoc cypress.com/go/plc Memory cypress.com/go/memory PSoC cypress.com/go/psoc Touch Sensing cypress.com/go/touch USB Controllers cypress.com/go/usb Wireless/RF cypress.com/go/wireless Cypress Developer Community Community | Forums | Blogs | Video | Training Technical Support cypress.com/go/support PSoC is a registered trademark of Cypress Semiconductor Corp. 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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. 001-86840 Rev. *B 5