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TPS61099: High efficiency boost converter device for IoT application

Fabio Leitao
Prodigy 150 points
Part Number: TPS61099
Other Parts Discussed in Thread: TPS61299, , TPS610985, TPS61299A

Tool/software:

Hi TI team,

We are designing an application with the following design configuration.

Basically, the design includes 2x batteries Li/SOCl2 using an ORing configuration, a MCU and a radio and a Sensor IC that requires a minimum voltage of 3V and a maximum operation current of 2mA.

In this case we think that a boost converter configuration would fit our design best.

Maybe we could get your help to find something that suits us.

Maybe the TPS61099 or the TPS610993 Vout = 3V, for better efficiency. The TPS61299 seems to be recent/improved but we are not sure about the efficiency for the same voltage configuration because only the Vout=5V is described in the datasheet.

The TPS610985 also seems very interesting in terms of efficiency.

Also some other device could be recommended.

However, it would be important to consider the following points:

  • When the Vin > Vout, Vout should follow Vin and show a low quiescent current.
  • It starts operating with seamless transition when the input voltage decreases approaching the configured 3V output.
  • High efficiency current under a light load considering that the current of the sensor IC in idle mode is ~5.25uA. So, something in this range is expected.
  • High efficiency when operating assuming that the sensor IC has a maximum current of 5mA.

Please let me know if some additional clarification is required.

Thank you for your support

  • 0
    TI__Expert 8965 points

    Hi 

    in normal operation, could I think of it as that the Vin of boost is 3.6V, in most case, the boost works in pass through mode. Then TPS61299A might suit as well. For the efficiency, you could refer to 3.3V output as reference. In pass through mode, the efficiency is about 98%~99%.

  • 0 in reply to Nini Zhong
    Prodigy 150 points

    Hi,

    Thank you for your suggestion.
    Considering the TPS61299A, Vin = 2V and configured to Vout = 3.2V, what would be the expected efficiency or input current assuming an output current of 1uA? and 5uA?

  • 0 in reply to Fabio Leitao
    TI__Expert 8965 points

    Hi 

    The efficiency is about 70%+. 

  • 0 in reply to Nini Zhong
    Prodigy 150 points

    I was looking for the TPS612993A but it is mentioned as product preview.

    So the availability doesn't seem good so we could do some testing.


    Is there any similar device / partnumber with similar efficiency as described before and "Force pass through" when disabled?

    Thanks

  • 0 in reply to Fabio Leitao
    TI__Expert 8965 points

    Hi Fabiao,

    Sorry that there is no such device with same high efficiency under uA level load, and the pass through when disabled. What is the volume of this project? We could provide samples of TPS612993A if needed. It is available for sample and if the customer request, there is chance to RTMed it.

  • 0 in reply to Nini Zhong
    Prodigy 150 points

    Hi Nini,

    Thank you for your reply.

    As a preliminary solution, we noticed that the TPS612994 (TPS612994YBHR) could be ordered for some initial testing. However, the TPS612994A (also mentioned as product preview)  with Force pass through and slightly higher input current limit, seems to meet better the requirements for our application.

    Therefore, considering the TPS612994A in DSBGA package, we would be interested in 60 samples for testing
    Then it would be planned an order of 250 parts still in July and 500 parts in September.
    Is there any specific contact that should be provided for further communication?

    In the meantime we plan to do some efficiency tests using the TPS612994.

    Just an additional question, what is the meaning of RTMed? :)

    Thank you for your attention.

  • 0 in reply to Fabio Leitao
    TI__Expert 8965 points

    Hi Fabio,

    TP612994A is 100mA, input current limit the same with TPS612994. tps612993a is 50mA. Could you give me the e-mail, we should know the customer's account name volume if you need samples.

  • 0 in reply to Nini Zhong
    TI__Expert 8965 points

    My e-mail is nini-zhong@ti.com

  • 0 in reply to Nini Zhong
    Prodigy 150 points

    Thank you for the information.
    We will get in contact soon regarding the volume data and samples request.

    Could you please clarify the following: 
    In the datasheet, it is mentioned a "EN pin pulldown resistor" of 800kohm.. is this an internal pulldown where the device is disabled by default?

  • 0 in reply to Fabio Leitao
    TI__Expert 8965 points

    It means just recommend to use a 800khoms resistor to pull down to gnd. It is outside the device.

  • 0 in reply to Nini Zhong
    Prodigy 150 points

    -Could you provide a bit more information about the purpose of this resistor? 
    Because this will add an extra uA current when EN is set to HIGH state. Or an additional circuit needs to be added to keep high efficiency.


    -Could this be disabled/enabled if tied to GND or VIN ( > 0.84V, assuming VIN >= 2V), what could be the disadvantage compared to the previous?
    -Could we use for example, a resistor divider (800kohm + 800kohm) as long we keep the voltage >0.84V? what is the leakage current that should be considered?

    Thank you for your support. 

  • 0 in reply to Fabio Leitao
    TI__Expert 8965 points

    Hi 

    the 800kohms resistor is just for anti-noise function. You could use other resistor as well. 

    The leakage current of EN is 1nA typically and max 50nA, other than uA level, I don't think it will add too much loss to the system.

    For 0.84V high , the Vin should be larger than 1.05V, but if Vin is lower than 1.05V, the EN high should be 0.56V.

    Actually personally there is no much advantage compared to just pull the EN high.

  • 0 in reply to Nini Zhong
    Prodigy 150 points

    Hi,

    Thank you for the clarification.
    We will perform some testing and contact you regarding the samples / volume.
    I think we can close the topic.

    Thank you very much for your support.

    Best regards,

    Fabio.

  • 0 in reply to Fabio Leitao
    TI__Expert 8965 points

    You are welcome.