{"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/em4100","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":"2026-11-01T22:00:29.087Z","chip":{"id":"b5077d66-3dbb-412b-956d-6f7e94a7d3ca","slug":"em4100","name":"EM4100","manufacturer":"EM Microelectronic","frequency_category":"LF 125 kHz","short_description":"Read-only 64-bit transponder, industry standard for access cards","manufacturer_url":"https://docs.rs-online.com/6ee7/0900766b8161beae.pdf","frequency":"100-150 kHz (typical 125 kHz)","protocol":"Proprietary EM4100 format, Manchester/Biphase/PSK encoding","memory":"64 bits total (factory laser-programmed, read-only): 9 header bits + 8 version/customer ID bits + 32 data bits + 10 row parity bits + 4 column parity bits + 1 stop bit","interface":"RF (contactless), no digital interface","temp_range":"-40°C to +85°C","form_factor":"Die (1016 × 1041 μm), CID package (8.5 × 4.0 mm, 2 pins), PCB package (8.0 × 4.0 mm, 2 pins), wafer/sawn wafer/sticky tape","security":"None (read-only, no encryption or authentication)","use_cases":["access-control","asset-tracking","animal-identification"],"engineering_brief":"The EM4100 is a classic 125 kHz read-only RFID transponder IC with 64 bits of factory-programmed memory. It is powered entirely by the reader's RF field (no battery) and uses load modulation to transmit data back at configurable rates (64/32/16 RF periods per bit) with Manchester, Biphase, or PSK encoding. The chip integrates a full-wave rectifier, 74 pF resonance capacitor, 120 pF supply capacitor, and voltage limiter, requiring only an external coil (~21.9 mH at 125 kHz). Its simple architecture, tiny die size, and very low power consumption make it ideal for disposable access cards, asset tags, and legacy RFID systems where unique read-only IDs suffice.","enriched":true,"url_status":"ok","link_status":"valid","last_checked":"2026-11-01T03:31:28.371+00:00","last_status_code":200,"last_content_type":"application/pdf","created_at":"2026-06-14T16:30:56.111445+00:00","manufacturer_id":"64ce2a57-06a6-425b-84dc-f4bd9eec0c36","chip_type":"tag_ic","dual_interface":false,"is_family_hub":false,"meta_description":"EM4100 is a 125 kHz read-only RFID tag IC with 64 bits factory-programmed memory, widely used in legacy access control and asset tracking systems.","faq":[{"a":"The EM4100 operates at 125 kHz (100-150 kHz range), a low-frequency RFID standard commonly used for proximity access control cards and asset tags.","q":"What frequency does the EM4100 RFID chip operate at?"},{"a":"No, the EM4100 is factory laser-programmed and read-only. The 64-bit memory (including 32 data bits and 8-bit customer ID) cannot be modified after manufacturing.","q":"Can the EM4100 memory be reprogrammed or written to?"},{"a":"No, the EM4100 is a fully passive transponder powered entirely by the RF field from the reader. It integrates a rectifier and voltage limiter to harvest energy from the 125 kHz carrier.","q":"Does the EM4100 require a battery?"},{"a":"The EM4100 supports Manchester, Biphase, or PSK encoding with configurable data rates of 64, 32, or 16 RF periods per bit for load modulation communication.","q":"What encoding does the EM4100 use for data transmission?"},{"a":"EM4100 chips are widely used in low-cost proximity access cards, asset tags, animal identification, and legacy RFID systems where simple read-only unique IDs are sufficient.","q":"What are the typical applications for EM4100 chips?"},{"a":"No, the EM4100 has no built-in security, encryption, or authentication. It is a simple read-only tag designed for applications where unique identification rather than security is the priority.","q":"Does the EM4100 support encryption or security features?"}],"standards":["iso-18000-2"],"alternatives":["3d5557e0-57db-43d5-81b6-19e1b2a93cab","a9e71908-817a-43b2-a0ce-0d180be72f27"],"no_direct_competitor":false,"long_form_html":null,"og_image_url":null,"canonical_url":"https://rfid-datasheet.com/chip/em4100"}}