SCBS881E January   2010  – October 2018 TMS3705


  1. 1Device Overview
    1. 1.1 Features
    2. 1.2 Applications
    3. 1.3 Description
    4. 1.4 Functional Block Diagram
  2. 2Revision History
  3. 3Device Characteristics
    1. 3.1 Related Products
  4. 4Terminal Configuration and Functions
    1. 4.1 Pin Diagram
    2. 4.2 Signal Descriptions
      1. Table 4-1 Signal Descriptions
  5. 5Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Electrical Characteristics
    5. 5.5 Thermal Resistance Characteristics for D (SOIC) Package
    6. 5.6 Switching Characteristics
    7. 5.7 Timing Diagrams
  6. 6Detailed Description
    1. 6.1  Power Supply
    2. 6.2  Oscillator
    3. 6.3  Predrivers
    4. 6.4  Full Bridge
    5. 6.5  RF Amplifier
    6. 6.6  Band-Pass Filter and Limiter
    7. 6.7  Diagnosis
    8. 6.8  Power-on Reset
    9. 6.9  Frequency Divider
    10. 6.10 Digital Demodulator
    11. 6.11 Transponder Resonance-Frequency Measurement
    12. 6.12 SCI Encoder
    13. 6.13 Control Logic
    14. 6.14 Test Pins
  7. 7Applications, Implementation, and Layout
    1. 7.1 Application Diagram
  8. 8Device and Documentation Support
    1. 8.1 Getting Started and Next Steps
    2. 8.2 Device Nomenclature
    3. 8.3 Tools and Software
    4. 8.4 Documentation Support
    5. 8.5 Community Resources
    6. 8.6 Trademarks
    7. 8.7 Electrostatic Discharge Caution
    8. 8.8 Export Control Notice
    9. 8.9 Glossary
  9. 9Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information


The TMS3705 transponder base station IC is used to drive the antenna of a TI-RFid transponder system, to send data modulated on the antenna signal, and to detect and demodulate the response of the transponder. The response of the transponder is a frequency shift keyed (FSK) signal. The high or low bits are coded in two different high-frequency signals (134.2 kHz for low bits and 123 kHz for high bits, nominal). The transponder induces these signals in the antenna coil according an internally stored code. The energy that the transponder needs to send out the data is stored in a charge capacitor in the transponder. The antenna field charges this capacitor in a preceding charge phase. The IC has an interface to an external microcontroller.

There are two configurations for the clock supply to both the microcontroller and the base station IC:

  1. The microcontroller and base station IC are supplied with a clock signal derived from only one resonator: The resonator is attached to the microcontroller. The base station IC is supplied with a clock signal driven by the digital clock output of the microcontroller. The clock frequency is either 4 MHz or 2 MHz, depending on the selected microcontroller type.
  2. The microcontroller and the base station each have their own resonator.

The base station IC has an on-chip PLL that generates a clock frequency of 16 MHz for internal clock supply only. Only TMS3705DDRQ1 is recommended in combination with AES transponder products (for example, TRPWS21GTEA or RF430F5xxx). TMS3705EDRQ1 is recommended for best performance in combination with DST40, DST80, MPT transponders (for example, TMS37145TEAx, TMS37126xx, TMS37x128xx, TMS37x136xx, TMS37x158xx, RI-TRP-DR2B-xx, RI-TRP-BRHP-xx) and cannot be used in combination with AES transponder products.

Device Information(1)

TMS3705EDRQ1 SOIC (16) 9.9 mm × 3.91 mm
TMS3705DDRQ1 SOIC (16) 9.9 mm × 3.91 mm
For the most current part, package, and ordering information for all available devices, see the Package Option Addendum in Section 9, or see the TI website at
The sizes shown here are approximations. For the package dimensions with tolerances, see the Mechanical Data in Section 9.