{"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/tms3705","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":"2026-11-01T19:50:00.751Z","chip":{"id":"1c1b33e3-ae96-4cbc-9b9a-371f64b029a8","slug":"tms3705","name":"TMS3705","manufacturer":"Texas Instruments","frequency_category":"LF 125 kHz","short_description":"HDX LF base station IC, automotive immobilizer","manufacturer_url":"https://www.ti.com/lit/ds/symlink/tms3705.pdf","frequency":"134.2 kHz (nominal); FSK demodulation at 134.2 kHz (low bits) and 123 kHz (high bits)","protocol":"TI-RFid HDX (Half-Duplex), FSK","memory":"N/A (base station/reader IC, not a transponder)","interface":"Antenna driver outputs (ANT1, ANT2 full-bridge), SCI (serial) interface to microcontroller (SCIO output), control inputs (TXCT, F_SEL), oscillator pins (OSC1, OSC2)","temp_range":"-40°C to +85°C","form_factor":"16-pin SOIC (D), 9.9 mm × 3.91 mm","security":"N/A (base station IC; compatible with AES transponders for TMS3705DDRQ1/GDRQ1 variants; TMS3705EDRQ1/FDRQ1 for DST/MPT transponders)","use_cases":["automotive-immobilizer","access-control","asset-tracking"],"engineering_brief":"The TMS3705 is a low-frequency (134.2 kHz) base station/reader IC for TI-RFid HDX transponder systems, designed for automotive and access-control applications. It drives an external antenna via a full-bridge output, sends modulated data to transponders, and demodulates FSK responses (134.2 kHz / 123 kHz). The IC includes an on-chip PLL (4 MHz or 2 MHz crystal input, 16 MHz internal clock), programmable frequency divider, digital demodulator, diagnosis, overcurrent protection, and low-power sleep mode (0.2 mA). It interfaces with an external microcontroller via SCI (asynchronous or synchronous mode) and control pins, and is qualified for automotive use (Q1). Variants TMS3705DDRQ1/GDRQ1 support AES transponders; TMS3705EDRQ1/FDRQ1 are optimized for DST40/80 and MPT transponders.","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":"76dcc3d3-1793-4a32-ae56-ffbffeedd8ee","chip_type":"reader_ic","dual_interface":false,"is_family_hub":false,"meta_description":"Texas Instruments TMS3705 is a 134.2 kHz LF base station/reader IC for TI-RFid HDX transponder systems, designed for automotive immobilizer and access control.","faq":[{"a":"The TMS3705 operates at a nominal frequency of 134.2 kHz and demodulates FSK responses at 134.2 kHz (low bits) and 123 kHz (high bits) from HDX transponders.","q":"What frequency does the TMS3705 reader IC operate at?"},{"a":"The TMS3705 uses an SCI (Serial Communications Interface) with SCIO output pin to communicate with an external microcontroller, supporting both asynchronous and synchronous modes.","q":"What interface does the TMS3705 use to communicate with a microcontroller?"},{"a":"The TMS3705 is a base station/reader IC, not a transponder. It drives an external antenna to power and communicate with passive HDX transponders in TI-RFid systems.","q":"Is the TMS3705 a transponder or a reader IC?"},{"a":"The TMS3705 supports TI-RFid HDX transponders. Variants TMS3705DDRQ1/GDRQ1 support AES-encrypted transponders, while TMS3705EDRQ1/FDRQ1 are optimized for DST40/80 and MPT transponders.","q":"What transponder types does the TMS3705 support?"},{"a":"The TMS3705 has a low-power sleep mode with a current consumption of approximately 0.2 mA, making it suitable for battery-powered or energy-conscious automotive applications.","q":"What is the sleep mode current consumption of the TMS3705?"},{"a":"Yes, the TMS3705 variants with Q1 suffix (e.g., TMS3705DDRQ1) are qualified for automotive applications and meet automotive-grade quality and temperature requirements.","q":"Is the TMS3705 qualified for automotive use?"}],"standards":["iso-11784-11785"],"alternatives":null,"no_direct_competitor":false,"long_form_html":null,"og_image_url":null,"canonical_url":"https://rfid-datasheet.com/chip/tms3705"}}