USB Power Charging System for Automotive Applications
Christine Halsey posted on June 19, 2014 |
TI's system charges virtually any external infotainment device.

Sometimes it's the little things that convince a buyer to choose your car model. From the 8-track to the tape cassette, to CD's and now infotainment systems; sometimes it's not the drive, the safety, or the mileage. Sometimes it's the frills.

Figure 1 - Car charging
More car models are coming out with USB outlets that allow you to connect or charge your external devices in the car. And if you expect a customer to spend tens of thousands of dollars on your product, the devices better work.

Ensuring the safety of an external device charging in your USB outlet can be a complicated task.  Every device can have a different power requirement. And let's be honest, no one wants to buy a separate car charger for their phones and tablets. Fortunately, TI (Texas Instruments) has developed a smart system that can identify the charging needs of every consumer electronic device that is in the vehicle.

TI's automotive power system will significantly reduce your efforts and time to market when designing an automotive infotainment system.  This stop-start USB power/charging solution will auto-detect:

  • BC1.2 for SDP (Standard Downstream Port), CDP (Charging Downstream Port)  & DCP (Dedicated Charging Port) up to 2Amps
  • Chinese Telecommunications Industry 2.0 Standard YD/T 1591-2009
  • USB 2.0 and 3.0

Once detected, the system will adjust the current to appropriate levels for the appliance. This provides a steady output power source and protection for all gadgets during Start-Stop applications. Additionally, the Q1 designation ensures it is automotive ready and compliant.

Figure 2 - Functional Block diagram TPS43330-Q1


TI started with the TPS43330-Q1.  It has a dual buck converter. Buck A can handle 6v-30v and supplies a steady 5v at 3mA. Buck B can handle 6v-30v and supplies 3.3v at 2mA.  It includes a voltage mode boost controller that ensures stability in case the input goes below 2v.  Check out the beginning of this video for a demonstration:

To connect the TPS43330-Q1 buck converter properly, TI has supplied a feature booklet complete with descriptions, ratings, thermal/electrical information, pin functions, and more.

Though the TPS43330-Q1 is a good power supply for various audio infotainment needs; it doesn't stop at entertainment. As seen in the video below, this chip can be used to power an emergency call system for up to 15 minutes.  Emergency call systems automatically call for assistance in the event of an accident. This ensures the driver and passengers can gain medical attention even when incapacitated.

For happier uses, TI has combined this reliable power supply with the TPS2543-Q1, a USB charging port power switch and controller.  It has an integrated USB 2.0 high-speed data line switch and has been tested on BC1.2 compliant and non-compliant devices.

Figure 3 - Functional Block diagram TPS2543-Q1


To further ensure safety, TI included the TPD2E001-Q1 into their USB charging system. It offers little to no signal distortion due to low input capacitance and ultra-low leakage current. TPD2E001-Q1 adds low-capacitance, 2-channel, ESD protection for:

  • ±15kv Human-Body Model
  • ±8kv Contact Discharge
  • ±15kv Air-Gap Discharge

TI wraps it all together by providing EVMs (Evaluation Modules) and simulation tools to help ease and speed your design and development.  Check out the TPS43330EVM  & TPS2543 USB Charging Port Power Switch & Controller EVM.

Also, check out TI's Automotive Infotainment Guide where you can learn about TI's other lines of automotive products for:

  • Audio
  • Data converters
  • Embedded processors
  • Interface
  • Microcontrollers
  • Power Management
  • Wireless Connectivity

With TI's USB power/charging system you can be confident of the safety and charge of your customer's external devices. Their complete solution will also ensure designs are quick to market for the automotive industry.

Texas Instruments has sponsored promotion of their automotive infotainment solutions on They have no editorial input to this post - all opinions are mine.  Christine Halsey


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