{"license":"Free for any use with attribution link to rfid-datasheet.com","citation":"RFID-Datasheet.com Chip Database — Roxtron","source":"https://rfid-datasheet.com/chip/em4550","methodology":"https://rfid-datasheet.com/methodology","data_notes":"Includes automated enrichment. Null means unknown; last_checked is link availability, not technical review. Manufacturer documents govern specifications.","generated_at":"2026-10-28T10:39:36.967Z","chip":{"id":"875c5f12-e18e-41de-845d-e5efa33eb791","slug":"em4550","name":"EM4550","manufacturer":"EM Microelectronic","frequency_category":"LF 125 kHz","short_description":"Read/write 125 kHz RFID IC with 1 Kbit EEPROM organized in 32 blocks for access control and identification","manufacturer_url":"https://www.emmicroelectronic.com/product/125khz-read-write-ics/em4550","frequency":"125 kHz","protocol":"EM Microelectronic proprietary LF protocol","memory":"1024 bits (128 bytes) EEPROM organized in 32 blocks of 32 bits each","interface":"RF (contactless)","temp_range":"-25°C to +85°C","form_factor":"Die (wafer)","security":"Password protection for read/write operations","use_cases":["access-control","asset-tracking","automotive-immobilizer"],"engineering_brief":"The EM4550 is a 125 kHz read/write RFID transponder IC featuring 1 Kbit of EEPROM memory organized into 32 blocks of 32 bits each. It supports password-protected read and write operations for secure data storage and retrieval in access control applications. The chip operates in the low-frequency band with contactless RF interface and is typically supplied as bare die for integration into various form factors including cards, key fobs, and tags.","enriched":true,"url_status":"ok","link_status":"invalid","last_checked":"2026-10-28T03:31:34.317+00:00","last_status_code":206,"last_content_type":"text/html; charset=UTF-8","created_at":"2026-07-11T03:00:26.165582+00:00","manufacturer_id":"64ce2a57-06a6-425b-84dc-f4bd9eec0c36","chip_type":"tag_ic","dual_interface":false,"is_family_hub":false,"meta_description":"EM4550: 125 kHz read/write RFID transponder IC with 1024-bit EEPROM, password protection, and 32-block organization for access control applications.","faq":[{"a":"The EM4550 features 1024 bits (128 bytes) of EEPROM memory organized into 32 blocks of 32 bits each. This memory is read/write capable with password protection for both read and write operations.","q":"What is the memory capacity of the EM4550 RFID chip?"},{"a":"The EM4550 operates at 125 kHz in the low-frequency (LF) RFID band using EM Microelectronic's proprietary protocol for contactless data communication.","q":"What frequency does the EM4550 operate at?"},{"a":"Yes, the EM4550 provides password protection for both read and write operations, enabling secure data storage and retrieval in access control and identification applications.","q":"Does the EM4550 support password protection?"},{"a":"The 1024-bit EEPROM is organized into 32 blocks, with each block containing 32 bits. This block structure allows for flexible data management and selective access to different memory regions.","q":"How is the EM4550 memory organized?"},{"a":"Both are 125 kHz read/write transponders from EM Microelectronic, but the EM4550 typically offers 1024 bits of memory with 32-block organization, while the EM4450 is a related device in the same family with similar read/write functionality.","q":"What is the difference between EM4550 and EM4450?"},{"a":"Yes, the EM4550 is typically supplied as bare die and can be integrated into various form factors including cards, key fobs, tags, and other access control devices.","q":"Can the EM4550 be used in card or key fob form factors?"}],"standards":["proprietary"],"alternatives":["9afbda6f-c632-4c8e-a25a-8a4c0134ee56","6fbf8d09-eab5-4645-a4ff-d46e5193497f","3d5557e0-57db-43d5-81b6-19e1b2a93cab","e825236d-3369-4e7d-a644-7a7373d5c023","a9e71908-817a-43b2-a0ce-0d180be72f27","de787ff0-5b24-47b3-b28b-3d404e2eda36","c322b9c5-6191-4fbf-a65e-2a4b8065da01","76109825-1a84-479b-b7e6-292856f3f4d9"],"no_direct_competitor":false,"long_form_html":null,"og_image_url":null,"canonical_url":"https://rfid-datasheet.com/chip/em4550"}}