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Texas Instruments TMS3705DDRQ1
- Part No.:
- TMS3705DDRQ1
- Manufacturer:
- Texas Instruments
- Category:
- RFID, RF Access, Monitoring ICs
- Package:
- 16-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
TMS3705DDRQ1.pdf
- Description:
- IC RFID READER 134.2KHZ 16SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,018
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Product details
Overview
TMS3705DDRQ1 from Texas Instruments is a transponder base station IC for TI-RFid™ RF identification systems, driving antenna coils in automotive immobilization and access control applications. It delivers FSK demodulation of 134.2 kHz/123 kHz transponder responses, integrates an on-chip 16 MHz PLL clock generator, and operates from 4.5–5.5 V with sleep-mode current as low as 0.2 mA.
For engineers reviewing the TMS3705DDRQ1 datasheet, TMS3705DDRQ1 pinout, TMS3705DDRQ1 application, or TMS3705DDRQ1 equivalent, this page provides verified functional context, SOIC-16 pin mapping, automotive-grade timing and power specifications, and validated alternative options for AES-compatible transponder systems.
Technical Context
The TMS3705DDRQ1 implements a full-bridge antenna driver with short-circuit protection, a 16-MHz PLL-derived carrier generator (configured via F_SEL), and a digital FSK demodulator that distinguishes high/low bits by frequency shift-not absolute frequency-using counter-based time-period measurement. Its RF amplifier features DC-coupled SENSE input, fixed 5× gain, and ≥2 MHz GBW to support low-pass filtering.
It supports two clock supply configurations: shared microcontroller-derived 2/4 MHz clock (TMS3705DDRQ1 recommended with AES transponders like TRPWS21GTEA), or independent resonator. Diagnosis occurs during charge phase using internal switchable SENSE resistor, and SCI interface outputs demodulated data synchronously or asynchronously to external MCU.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Data rate | Up to 8 kbps - enables fast transponder interrogation in car access and immobilization sequences |
| Carrier frequency | Nominal 134.2 kHz (FSK: 123 kHz / 134.2 kHz) - matches TI-RFid transponder resonance standards |
| Supply voltage | 4.5–5.5 V - compatible with standard automotive 5-V rail and regulator outputs |
| Sleep current | 0.015–0.2 mA - minimizes standby power in battery-powered access readers |
| PLL output | 15.984–16.0166 MHz - stable internal clock source for timing-critical demodulation and bridge control |
| Antenna drive | Full-bridge output with ≤14 Ω total RDS(on) - delivers sufficient current into 100–1000 µH antenna coils |
| Diagnostic threshold | 80–240 µA at SENSE - verifies antenna continuity and coil integrity before transmission |
Pinout & Package
Package: 16-pin SOIC (D), body size 9.9 mm × 3.91 mm, JEDEC-standard footprint with thermal resistance RθJA = 130 °C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 SENSE | Analog input | DC-coupled RF amplifier input; used for antenna diagnosis and signal detection |
| 2 SFB | Analog output | RF amplifier output feeding band-pass filter and limiter stage |
| 3 D_TST | Digital output | PLL clock test output; confirms 16 MHz operation during validation |
| 4 A_TST | Analog output | Analog test point for RF amplifier and limiter stages |
| 5 ANT1 / 7 ANT2 | Driver outputs | Full-bridge terminals driving antenna coil; short-circuit protected, ±1.1 A peak |
| 6 VSSA / 8 VDDA | Power rails | Separate analog ground and supply for full-bridge drivers to minimize noise coupling |
| 9 VDD / 12 VSS/VSSB | Power rails | Digital core supply and ground; includes PLL and logic blocks |
| 10 OSC2 / 11 OSC1 | Oscillator I/O | Supports external 4 MHz ceramic resonator or MCU-derived 2/4 MHz clock input |
| 14 SCIO | Digital output | SCI-encoded serial data output to MCU; supports synchronous or asynchronous mode |
| 15 F_SEL | Digital input | Selects PLL multiplication factor (×4 default); determines internal clock generation mode |
| 16 TXCT | Digital input | Transmit control signal from MCU; initiates charge, read, write, and diagnostic phases |
Key Features
| Feature | Design Value |
|---|---|
| Integrated PLL clock generator | Generates precise 16 MHz internal clock from 2/4 MHz external source-eliminates need for separate crystal in AES-compliant designs |
| FSK digital demodulator | Distinguishes transponder bits by frequency shift (not absolute frequency), enabling robust decoding despite ±10% resonance tolerance |
| Full-bridge antenna driver | On-chip N/P-channel MOSFET bridge with ≤14 Ω RDS(on) and <10 µs short-circuit shutdown-reduces BOM count and layout complexity |
| On-the-fly resonance measurement | Measures transponder's 123 kHz low-bit frequency during prebit phase and auto-adjusts carrier divider-ensures optimal coupling across temperature and coil variance |
| Dual-mode SCI interface | Configurable synchronous or asynchronous serial output (SCIO) with programmable bit timing-simplifies MCU firmware integration |
| Integrated diagnosis circuit | Verifies antenna continuity and driver functionality during charge phase using internal switchable SENSE resistor-enables fail-safe system startup |
Applications
| Automotive Immobilization | Car Keyless Entry |
|---|---|
|
Use Scenario: Embedded in vehicle ECU to authenticate encrypted transponder keys during ignition sequence. IC Role / Device Role / Timing Role: Base station IC generating 134.2 kHz magnetic field, demodulating AES-encrypted FSK response, and delivering decoded ID via SCIO to MCU. Use Value: Enables secure, low-power authentication with <0.2 mA sleep current and integrated PLL-no external clock required when paired with AES transponders. |
Use Scenario: Integrated into door handle modules to detect proximity and unlock doors upon valid key presence. IC Role / Device Role / Timing Role: Drives antenna coil, performs real-time resonance tuning, and decodes transponder ID within <3 ms after TXCT assertion. Use Value: Supports fast wake-up (<2.2 ms initialization) and reliable detection at >20 cm range using 100–1000 µH antennas. |
| Building Access Control | Livestock RFID Reader |
|
Use Scenario: Used in wall-mounted access panels to verify employee badges before granting entry. IC Role / Device Role / Timing Role: Provides regulated antenna drive, FSK demodulation, and diagnostic feedback to ARM-based controller over SCIO interface. Use Value: Delivers automotive-grade reliability (–40°C to +85°C) and built-in short-circuit protection-reducing field failure risk in unattended installations. |
Use Scenario: Deployed in handheld livestock readers to identify ear-tag transponders in barn environments. IC Role / Device Role / Timing Role: Supplies charge-phase energy, measures transponder resonance, and outputs decoded ID bytes synchronously to low-power MCU. Use Value: Enables battery-operated operation with 0.2 mA sleep current and robust FSK decoding-even with variable coil coupling and EMI. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar transponder base station applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TMS3705GDRQ1 | Direct replacement per TI documentation; identical SOIC-16 package, same 16 MHz PLL, and AES transponder compatibility | No functional difference; qualified for same AES transponder products (e.g., TRPWS21GTEA, RF430F5xxx) | Select TMS3705GDRQ1 for new designs where long-term availability and latest revision status are prioritized |
| TMS3705FDRQ1 | Optimized for DST40/DST80/MPT transponders; different F_SEL behavior and PLL configuration; not AES-compatible | Designed for legacy transponder families only; incompatible with AES transponders due to timing and modulation constraints | Do not substitute for TMS3705DDRQ1 in AES-based systems-use only if migrating to DST-family transponders |
Compared with TMS3705DDRQ1, TMS3705GDRQ1 offers identical electrical and functional performance with updated manufacturing and qualification, while TMS3705FDRQ1 serves a distinct transponder ecosystem and must not be used interchangeably in AES applications.
Availability
TMS3705DDRQ1 is available at Aetrix Electronics and suitable for automotive immobilization, keyless entry, and building access systems requiring stable component supply, long-lifecycle support, and AEC-Q100-aligned design assurance.
Supply support for TMS3705DDRQ1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor company specializing in analog, embedded processing, and wireless connectivity solutions, with deep expertise in automotive and industrial system-on-chip design.
The TMS3705 product line delivers integrated transponder base station ICs optimized for TI-RFid™ systems-designed specifically for secure, low-power, magnetic-field-based identification in automotive and access control applications.
FAQ
What is the primary function of the TMS3705DDRQ1 in a TI-RFid™ system?
The TMS3705DDRQ1 serves as the transponder base station IC, driving the antenna coil, transmitting modulated data, and detecting/demodulating FSK responses from TI-RFid™ transponders. It integrates a full-bridge driver, RF amplifier, band-pass filter, limiter, digital demodulator, and PLL clock generator-all in a single SOIC-16 package. Its design enables secure, low-power communication with AES transponders such as TRPWS21GTEA and RF430F5xxx.
Why is the TMS3705DDRQ1 specifically recommended for use with AES transponder products?
The TMS3705DDRQ1 is explicitly recommended by Texas Instruments for AES transponder products (e.g., TRPWS21GTEA, RF430F5xxx) because its PLL configuration, timing parameters, and FSK demodulation logic are tuned to meet AES protocol requirements-including precise 134.2 kHz/123 kHz frequency discrimination and secure data handshaking. Other variants like TMS3705FDRQ1 are incompatible due to differing modulation handling and register settings.
Does the TMS3705DDRQ1 require an external crystal or resonator?
No-the TMS3705DDRQ1 does not require an external crystal. It features an on-chip PLL that generates a stable 16 MHz internal clock from either a 4 MHz ceramic resonator (connected between OSC1/OSC2) or a 2/4 MHz digital clock signal driven by an external microcontroller. This eliminates the need for a separate crystal in AES-compliant designs and reduces bill-of-materials cost.
How does the TMS3705DDRQ1 perform antenna diagnosis, and what pins are involved?
The TMS3705DDRQ1 performs antenna diagnosis during the charge phase by switching an internal resistor to ground at the SENSE pin, forming a voltage divider with the external SENSE resistor. If the resulting current exceeds 80–240 µA, the diagnosis passes and the system proceeds. This function uses only SENSE (pin 1), VSSA (pin 6), and VDDA (pin 8), and is fully integrated-requiring no external components or MCU intervention.
What are the key differences between TMS3705DDRQ1 and TMS3705GDRQ1?
TMS3705GDRQ1 is documented by Texas Instruments as the direct replacement for TMS3705DDRQ1, sharing identical electrical specifications, pinout, package (SOIC-16), and AES transponder compatibility. The GDRQ1 variant reflects updated process technology and extended lifecycle support but maintains full functional and mechanical equivalence-making it suitable for drop-in replacement in existing designs and preferred for new projects.
TMS3705DDRQ1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Type:
- RFID Reader
- Frequency:
- 134.2kHz
- Standards:
- -
- Interface:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- Automotive
- Qualification:
- AEC-Q100
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-SOIC
TMS3705DDRQ1 FAQ
1.How can I place an order for TMS3705DDRQ1 through Aetrix?
Please submit a Request for Quotation (RFQ) for TMS3705DDRQ1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for TMS3705DDRQ1 reliable?
The price and inventory of TMS3705DDRQ1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for TMS3705DDRQ1 is usually 5 days.
3.What payment methods are accepted for TMS3705DDRQ1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for TMS3705DDRQ1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for TMS3705DDRQ1?
TMS3705DDRQ1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your TMS3705DDRQ1 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for TMS3705DDRQ1?
For technical support, including TMS3705DDRQ1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your TMS3705DDRQ1 requirements.
6.How does Aetrix verify that TMS3705DDRQ1 is sourced from the original manufacturer or authorized distributors?
All TMS3705DDRQ1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that TMS3705DDRQ1 meets industry standards.
7.What is the process for return or replacement of TMS3705DDRQ1?
All TMS3705DDRQ1 units undergo pre-shipment inspection (PSI). If there is an issue with TMS3705DDRQ1, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The TMS3705DDRQ1 part is unused and in its original packaging.
Return procedure for TMS3705DDRQ1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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