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TPS65070: Powering up TPS65070

Part Number: TPS65070
Other Parts Discussed in Thread: TPS3823,

Hello,

Can you pls. clarify how to start up the TPS65070 to achieve the following things:

Note: I don`t use a possibility of turning TPS65070 on and off using a button.

My application is such that should not require an ON-key but shall power-up automatically once supply voltage is applied.

The device must do the following things:

1. Turn ON from USB/AC when there are USB/AC supply and LiPo Battery charging.

2. Turn ON from Li-Ion battery when there is no USB/AC supply.

3. Should Work until battery will be discharged (VBAT < VUVLO)  when there is no USB/AC supply.

4. Should automatically turn ON the system(Load) when AC/USB again get plugged while charging the battery on one hand.

How should be the PB_IN# and POWER_ON hardware and software configuration??

Please let me know what should be done to make the above function done?? How should be the hardware connection?? How can we make it possible without using any external hardware other than Microcontroller which has to be powered from the TPS65070 only?

I have gone through this thread, did it work??: 

Thanks in advance.

  • Hi,

    I have assigned this to the responsible engineer. They will get back to you shortly.

    Thanks,
    Nastasha
  • Madhu,

    In your previous thread, you decided on using the TPS65070 for your design.

    Do you have a schematic yet of the design?

    Please confirm what type of battery you are using, LiPo or Li-Ion. You mention both above.

  • Brian Berner,

    Do you have a schematic yet of the design?

    Reply: Yes, Please look into the schematics and answer the previous thread.

    Please confirm what type of battery you are using, LiPo or Li-Ion. You mention both above.

    Reply: Both will be used - Li-Po or Li-Ion Cells.

    In addition to Queries asked in the Previous thread, Please clarify the following also:

    Query:

    I want to use Case C in the TI document provided(http://www.ti.com/lit/an/slva512/slva512.pdf). But here in the Case C, it is not mentioned about the scenario where if there is battery also connected and getting charged as long as there is AC or USB which is providing supply to load, then soon after the AC or USB disconnected Will the battery come into the picture and provide supply to the Load without the need of pulling the PB_IN# to LOW????  

    Could you please explain the Case C by considering that Battery is also connected to PMIC battery terminals??

    I came across other few possibilities to made it work, please check if any of the following will work:

    - Using OR Gate at PB_IN# of the PMIC 

    OR gate A terminal OR gate B terminal PB_IN#
    1 0 HIGH
    0 0 LOW

    - Using TPS3823 Voltage Monitor With Watchdog Timer

    This was discussed in this thread: https://e2e.ti.com/support/power_management/pmu/f/200/t/153041?tisearch=e2e-quicksearch&keymatch=battery%20discharged

    Regards,

    Madhuwesly.

  • Hello Brian,

    Did you get a chance to look into this? We need this confirmation to proceed with our design.

    Thanks,

    Avinash Dara

  • Avinash,

    I am still reviewing you use case.

    In the meantime, there is a lot of material on the TPS65070 in the FAQ section of e2e: e2e.ti.com/.../2903.tps6507x-faqs

    These FAQs may assist in answering a lot of your questions here while I review your proposed design.
  • Hello Brian,

    Thanks, will go through it.
  • Went through the material, it gave some more insights on the PMIC. But, we couldn't find a reference to the current issue we're discussing here.

    To restate the question in simple terms, we want to use the PMIC[with battery and AC supply] without an application processor. We just want to ensure that PMIC powers up in all cases automatically without any need for external intervention.

    We went through the datasheet and application notes on how to power up, any help on how to configure it in above mode is appreciated.

    Thanks,
    Avinash Dara
  • Madhu,

    It is impossible to have the TPS65070 power-up from the "Power OFF" state to the "ON" state without PB_IN toggling (Hi-->Lo-->Hi) when BAT power is the only available power supply.

    You can read Section 10.3.11.3 and refer to Figure 34. State Machine on page 35 of the TPS65070 datasheet.

    Keep in mind that PB_IN cannot simply be shorted to GND either, as you have done in your design, because the text says "...there is a 15-s timer [on PB_IN] which will drive PGOOD=LOW for 0.5 ms when 15 s are expired. The 15- s timer is enabled again when PB_IN is released HIGH."  The simplest way to make the PB_IN signal work correctly is to connect it to a physical push-button. 

    Madhu Wesly said:
    battery also connected and getting charged as long as there is AC or USB which is providing supply to load, then soon after the AC or USB disconnected Will the battery come into the picture and provide supply to the Load without the need of pulling the PB_IN# to LOW????  

    Answering this question depends on the order of events.

    This order of events will work seamlessly without pressing the Push-Button (PB_IN)

    1. AC or USB connected
    2. AC or USB supplies current to SYS (as long as POWER_ON == 1, DCDC and LDO will start-up and stay on) 
    3. Battery connected
    4. Battery starts charging
    5. AC or USB removed
    6. Battery supplies current to SYS

    This order of events will not work without pressing the Push-Button (PB_IN)

    1. Battery connected
    2. BAT cannot supply current to SYS without PB_IN toggle
    3. AC or USB connected
    4. AC or USB supplies current to SYS (as long as POWER_ON == 1, DCDC and LDO will start-up and stay on) 
    5. Battery starts charging
    6. AC or USB removed
    7. Battery supplies current to SYS

    Your system will depend 100% on AC or USB being applied to turn on the system. After AC or USB is applied everything will work correctly, but is it OK for you that the system cannot power-on from OFF state if only the BAT is applied without AC or USB? It is possible this is OK, but only you can answer this question.

    From my point of view, logic circuitry can be used to imitate a physical push-button but it needs to be tested and validated in your system. The only way to guarantee the circuit works 100% of the time is to connect a physical push-button to the PB_IN pin.

  • It is possible to pull up POWER_ON to SYS in order to keep the system power on, because SYS will be supplied by AC or USB immediately and SYS is supplied by BAT as soon as PB_IN is toggled.

    The datasheet says: "Pulling POWER-ON to a supply voltage would significantly reduce the time PB_IN has to be asserted LOW"

    This will prevent the need for a GPIO to control this pin.
  • Hello Brian,

    Thanks for the confirmation.

    Note: In my scenario POWER_ON will always be pulled-up to SYS.

    My scenario will be Case 1. I just want to confirm one more thing in Case 1 that, will Event 6(Battery supplies current to SYS) turn ON/start-up DCDCs and LDOs and keep them stay on? Will this ON-OFF-ON occur while switching the load from Event 5 to 6 or will the converters stay ON continuously even if during the switching from event 5 to 6??  

    Regards,

    MadhuWesly.

  • Madhu Wesly said:
    The converters stay ON continuously even if during the switching from event 5 to 6

    This is the true statement, as long as POWER_ON stays high during the switching event.

    In my test setup on the TPS65070EVM-430, I used AC = 5V and BAT = 3.5-4.2 and toggled AC repeatedly by turning this supply ON/OFF/ON manually at a slow rate (every 3-4 seconds).

    SYS is always supplied by AC when it is available and automatically switches over to BAT when AC is removed. When BAT < 4.2V, AC tries to charge the battery at 500mA. When BAT = 4.2V, charging stops. In either case, BAT supplies SYS when AC is removed.

    The only time the PB_IN is needed is when AC does not exist and BAT is applied first as the only power supply. After the initial power-on event, SYS will continuously be supplied by AC, USB, or BAT as long as at least 1 stable supply is available and >UVLO.