• State
  • Locked Locked
  • Replies 4 replies
  • Subscribers 62 subscribers
  • Views 891 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS61200 leakage quiescent current

Bishan Singh
Prodigy 185 points
Other Parts Discussed in Thread: TPS61200, TPS60400

Hi,

I am using TPS61200 boost converter to boost voltage from 3.7V li-ion cell to 5V. I have pull down down PS pin to preserve power.

In off state (when EN pin is low), the quiescent current is 5uA and when the EN pin is high everything turns on and I get my 5V.

Now Problem, If after TPS61200 I use TPS60400 for -5V then even at off state the current increases to 250uA. 

Why this behavior when EN pin is LOW i.e. in off state.

Regards

Bishan Preet Singh 

  • 0
    TI__Intellectual 2270 points

    Hi

    I suppose it's caused by the quiescent current of TPS60400. here is my thought, for tps61200, it's not a true shutdown device, that means even though EN pin is pulled low, the backgate diode of high side MOS will conduct when Vout drops below Vin-Vdio(about3.7V-0.7V=3V). so the power supply for TPS60400 will be 3V. on tps60400 D/S page 6, it's quiescent current will be about 200uA. please check the input of the tps60400(ie. output of tps61200) to confirm it. 

    thanks

    Charles from Boost Converter Solutions

  • 0
    TI__Intellectual 2270 points

    sorry, i treat tps61200 as a non true shutdown device by mistake. actually it's a true shutdown device. so the output will be 0V, can u help check the Vout of tps61200 ? thanks

  • 0 in reply to Charles Wong1
    Prodigy 185 points

    Mr charles,

    Thanks, I appreciate your prompt reply.

    I think you were right earlier, the TPS61200 is not a true shutdown device. I am getting 0.7V at the output after directly pulling down the EN pin,  Can you confirm that at your end too ?

    Yes I removed the TPS60400 but the leakage current remains the same.

    The 5V volt was connected to ground with 1K and 3K resistor, providing the gain for opamp. When I removed that the leakage current was half. I guess the TPS61200 is not turning off completely even after connecting EN pin to ground directly.

    Can you suggest me something ?

    Regards

    Bishan Preet Singh

  • 0 in reply to Bishan Singh
    TI__Intellectual 2270 points

    Hi Brishan,

    sorry for my late reply.

    tps61200 is a true shutdown device. it's cinfirmed on EVM, we can get 0V after EN is pulled low. it's hard to guess why Vout is 0.7V when EN is low at your end. can u replace with a new part to double check this issue?

    if still the same, can u share the schematic of the system and capture the tps61200 EN VOUT VAUX waveforms?