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TPS2544EVM-064 not working with Motorola Droid RAZRs

Other Parts Discussed in Thread: TPS2544EVM-064, TPS2546, TPS2544

We are using the TPS2544EVM-064 to test charging on several phones (about 7 or so). It looked good until we plugged in a Motorola Droid RAZR-M & RAZR-MAX. For both of those phones, there was no current draw. Any idea what may be going on?

We can interchange phones at will. Whenever the 2 Motorola RAZRs are attached, they draw no current whatsoever. Old phones draw about 50mA, and the newest Samsung phone draws about 700 mA. An HTC phone (about 2 years old) draws 400 mA. We can cycle repeatedly, always get the same results.

  • Tom, we are studying the device compatibility list to see if the RAZR's have been tested. Are these Motorola devices new to the market?

  • These were released in September 2012.

    http://en.wikipedia.org/wiki/Droid_Razr_M

  • Tom Saluzzo said:

    We are using the TPS2544EVM-064 to test charging on several phones (about 7 or so). It looked good until we plugged in a Motorola Droid RAZR-M & RAZR-MAX. For both of those phones, there was no current draw. Any idea what may be going on?

    We can interchange phones at will. Whenever the 2 Motorola RAZRs are attached, they draw no current whatsoever. Old phones draw about 50mA, and the newest Samsung phone draws about 700 mA. An HTC phone (about 2 years old) draws 400 mA. We can cycle repeatedly, always get the same results.

    Hello,

    I checked online, seems that phone only release to Verizon. So it will be a little hard for us (China Team) to find that phone for test. So could you please upload the waveform when plugin? D-, D+, and VBUS are needed for analysis.

  • Customer is wating for their scope to arrive to gather the data you requested.

    I connected the TPS2546 eval module to the Motorola RAZR phone and got the same result – zero charging current. All other phones charged at various levels – with newer phones pulling around 400-500 mA. This test setup was using a +5 VDC power supply that has a built-in current monitor – so we could see how much current we were supplying to the phone. 

    As a last ditch effort, instead of using a power supply, I connected the eval module to a PC USB port, and then to the RAZR. The phone started to charge – although I couldn’t tell how much current was being supplied – but because it’s a PC, I bet it was limited to <= 500 mA.

     I looked at the eval module schematic. It should not make a difference if I use a + 5 VDC power supply or a USB port to provide power – but the USB port also had DP and DM (the comm lines), and the power supply only had power & ground.

     Then I tried the TPS2544 eval module with a PC USB port. It also charged the phone.

    Why does the TPS2544 & TPS2546 need a USB port on the input side in order to charge a RAZR, but doesn’t need it for the Samsung & HTC smartphones?

    On a competitive module, all phones were instantly charging. But more than that, when we plugged in a Samsung phone, which has the largest battery, the competitive solution provided 800-900 mA of charging, while the TI solution only provided 400-500 mA. Why does the TI part provide about half of the charging current as the competitive solution?

  • Hello Tom,

    We are looking into the issue right now.

     

     

    Best regards,

     

    Max

  • Tom,

    During the test, TPS2544 is set at CDP 1111 mode, right?

    In CDP or SDP, TPS2544 D+/D- is by-pass between USB Host and portable devices, (CDP adds in CDP handshake).

    If you a PC, whcih can do data communication with Moto phone, it can do charging and data at same time.

    With a Host, just use TPS2544 in CDP mode, which means the port has no data communication ability, it depends on phones how they behave. Moto may choose not to charge, while HTC or Samsung would choose to charge anyway.

    It can explain why Moto phone can charge when you use PC for test, while can't charge without PC.

    If set TPS2544 in Dedicated Charging Port (0111), which is charging only, no data; then no host is needed, TPS2544 can support most of popular devices fast charging.

    Hope it can help!