AN206 Migrating from FM24L256 to FM24V02 Author: Girija Chougala Associated Project: No Associated Part Family: FM24L256, FM24V02 Software Version: None Related Documents: For a complete list, click here AN206 discusses the key differences that need to be considered when migrating from FM24L256 to FM24V02. FM24L256 is now obsolete and this application note explains how FM24V02 is a replacement for FM24L256. Table 1 shows the compatibility chart of FM24L256 and FM24V02. For a detailed comparison, see Table 3. Introduction FM24V02, a 256-Kbit I2C F-RAM™, is a replacement device for FM24L256, which is now obsolete. The two devices are identical in terms of pinout, package composition and dimensions, read/write functionality, Write Protect operation, and address pin functionality. This application note discusses the key differences between the two devices that need to be considered when migrating from FM24L256 to FM24V02. Drop-In Replacement or Not? For most designs, FM24L256 is a drop-in replacement for FM24V02. From a software point of view, the two devices are identical. From a hardware point of view, FM24V02 has higher standby current. The FM24V02 adds many features like operation down to 2.0 V, sleep mode capability and Device ID feature. The FM24V02 incorporates a HS-mode that allows read/write operations up to 3.4 MHz. The sleep mode feature effectively lowers the standby/idle current to 8 µA. Table 1. Compatibility Chart FM24L256 Feature or Spec Is FM24V02 compatible? Package Yes Pinout Yes Temperature Range Yes Operating Voltage Yes Operating Current Yes Standby Current No Read / Write Function Yes Timing / Frequency Yes Data Retention Yes Endurance Yes Ordering Part Numbers Table 2 gives the recommended FM24V02 ordering part numbers that correspond to the now obsolete FM24L256 ordering part numbers. Table 2. Recommended Ordering Part Numbers for Migration FM24L256 Ordering Part Number FM24L256-G FM24V02 Status Obsolete Comments Ordering Part Number FM24V02-G Status In production No hardware or software change is required. System software update is required if you wish to use the FM24L256-GTR FM24V02-GTR additional Device ID feature supported in FM24V02. www.cypress.com Document No. 001-86827 Rev. *B 1 Migrating from FM24L256 to FM24V02 Comparison of FM24L256 and FM24V02 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 Sleep Mode Current Output LOW Voltage (VOL) Read / Write Function Clock Frequency FM24L256 FM24V02 -G -G SOIC-8 SOIC-8 - - Identical –40 ºC to +85 ºC –40 ºC to +85 ºC Identical 2.7 V to 3.6 V 2.0 V to 3.6 V 70 µA @ 100 kHz 175 µA @ 100 kHz 600 µA @ 1 MHz 400 µA @ 1 MHz 12 µA 150 µA - 8 µA FM24V02 offers a sleep mode which can be used to reduce the standby/idle current. During wake-up from sleep mode, the device has a recovery time of 400 µs. 0.4 V @ IOL = 3 mA 0.4 V @ IOL = 2 mA FM24L256 has better output LOW specification - - Identical 2-byte addressing, Identical Slave IDs, Identical device select bits 1 MHz 1 MHz Comments Identical, “green” SOIC Identical outline and board footprint FM24V02 allows operation down to 2.0 V FM24V02 offers lower active current at 1 MHz. FM24V02 has higher standby current Identical 10 years (+85 ºC) Data Retention 10 years (+85 ºC) 38 years (+75 ºC) Identical 151 years (+65 ºC) FM24V02’s endurance is large enough to be considered as unlimited for all practical applications. For a 64-byte loop at 1 MHz, FM24V02’s endurance is 1700 years. Endurance (Write/Read Cycles) Unlimited 1E+14 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 5 ms 0.25 ms FM24V02 is faster to first access HS-mode Clock Frequency - 3.4 MHz FM24V02 supports higher clock frequency of 3.4 MHz through a new command Device ID Feature - Yes Power-up to First Access (tPU) Additional feature in FM25V02 Critical Considerations You should consider all the parameter differences mentioned in Table 3 during the migration to FM24V02. This section discusses the critical differences. System designers should also review the datasheet when migrating to the new part. Standby Current / Sleep Mode Current The FM24V02 has higher standby current of 150 µA compared to 12 µA of FM24L256. But FM24V02 offers an additional sleep mode feature which can be used to reduce the standby/idle current. The sleep mode current is as low as 8 µA. Note that during wake-up from sleep mode, the device needs a recovery time of 400 µs. www.cypress.com Document No. 001-86827 Rev. *B 2 Migrating from FM24L256 to FM24V02 New Feature This section discusses the additional Device ID feature supported in FM25V02. System designers should also review the datasheet for more details on the device ID feature. Device ID Feature The FM25V02 incorporates a 9-byte read only Device ID (004200h) to identify the product uniquely. The Device ID allows the host to determine the manufacturer, product density, and product revision. System firmware update is required when you wish to use this feature in FM25V02. Summary AN206 discussed the differences between FM24L256 and FM24V02 that need to be considered during migration to the FM24V02. Related Documents Datasheet FM24V02: 256-Kbit (32 K × 8) Serial (I2C) F-RAM datasheet www.cypress.com Document No. 001-86827 Rev. *B 3 Migrating from FM24L256 to FM24V02 Document History Document Title: Migrating from FM24L256 to FM24V02 - AN206 Document Number: 001-86827 Revision ECN Orig. of Change Submission Date Description of Change ** 3944550 GVCH 03/26/2013 New Spec. *A 4281483 MEDU 03/05/2014 Updated to Cypress Template. Removed VIH(max) specification from Table 2. *B 4498650 GVCH 09/10/2014 Changed title from “Differences between FM24L256 and FM24V02” to “Migrating from FM24L256 to FM24V02.” Updated abstract. Added “Ordering Part Numbers” section. Added title for Table 3. Added “New Feature” section. Added “Related Documents” section. www.cypress.com Document No. 001-86827 Rev. *B 4 Migrating from FM24L256 to FM24V02 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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