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TPS62082: DC-DC step down 5V to 3.3V 0.3A for wireless connectivity solutions

Emilija Zukauskaite
Expert 1100 points
Part Number: TPS62082
Other Parts Discussed in Thread: LM3281, TPS62821, TPS62172, TPS62561, TPS62170, TPS62230, TPS62056

Hi,

I'm looking for LM3281 replacement that converts 5V to 3.3V. I cant solder BGA packages and LM3281 is BGA. QFN or any other will be fine. I need the part that is low noise and suitable for the wireless application. One post suggested TPS62082 but it doesn't say that its good for wireless. 

Thank you.

Emilija

  • 0
    TI__Expert 3645 points
    Hello,
    I can suggest TPS62821 for mobile computing and network cards with Iout= 1A and QFN package. If you want you can look for also other suitable devices for your application at this page: www.ti.com/.../overview.html
  • 0 in reply to Alfonso Furio
    Expert 1100 points
    HI Alfonso,

    Is TPS62821 the best for wireless?
    I searched for DC-DC converters and there are many options but I dont know which one is good for wireless. We are using Lora, Bluetooth and 2.4GH Wi-Fi.

    Thank you and Regards,
    Emilija
  • 0 in reply to Emilija Zukauskaite
    TI__Expert 3645 points
    Hello,
    I looked again in our portfolio, and I found another solution that can fit your specs, especially in terms of output current rate. You can have a look at the D/S of TPS62237: www.ti.com/.../tps62230.pdf
    The previous solution is also suitable but has a higher output current.
  • 0 in reply to Alfonso Furio
    Expert 1100 points

    Hi Alfonso,

    TPS62237 looks like a good solution! But the USON package still has pads underneath, almost like BGA and I dont think I could solder it by myself. I tried searching and I found this part TPS62172 in QFN package. What do you think of this part for wireless? Do you have any more suggestions?

    Thank you.

    Regards,

    Emilija

  • 0 in reply to Emilija Zukauskaite
    Expert 1100 points

    Hi Alfonso,

    I realised that TPS62172 part might not be the best solution because it goes to a power save mode at light loads. I think I need a fixed frequency dc-dc for a wireless application. Maybe part TPS62561 would be better?

    I couldn't find an IC that has a high switching frequency, force pwm mode and that can take a higher input voltage. I'm looking for a solution that could accept 3.5V to 9V and outputs 3.3V. I'm using TPS630701 part already which can do that. Do you have any simpler solutions?

    Thank you.

    Regards,
    Emilija

  • 0 in reply to Emilija Zukauskaite
    TI__Expert 3645 points
    Hello Emilija,
    can you summarize which specs do you need? I understood that you need something for a wireless, but it could be helping to know other details related to your application (i.e., is it a battery powered application? etc…).
  • 0 in reply to Alfonso Furio
    Expert 1100 points
    Hi Alfonso,

    Vin is 3.5-4.2V lithium battery. But it might be powered by 8V.
    Vout 3.3V fixed to provide power to IoT module which uses Wi-Fi 2.4 GHz and Lora. Output current is maximum 0.5A.

    Thank you.

    Regards,
    Emilija
  • 0 in reply to Emilija Zukauskaite
    TI__Expert 3645 points
    Hello,
    if you require a fixed-frequency device, I can suggest TPS62811 (pre-samples of TPS62812 (2A) are available to start with some measure). If fixed-frequency is not strictly required (because not mentioned in the last post) you can have a look of TPS62237 with forced PWM (you set from Mode pin); the DCS control topology is suitable for very low noise application. Finally, if the input voltage goes up to 8V, have a look into TPS62170/2.
  • 0 in reply to Alfonso Furio
    Expert 1100 points

    Hi Alfonso,

    TPS62230 has a package with pads underneath so I dont think I will be able to solder it by myself.

    TPS62170 doesn't have a forced PWM. It looks like that TPS630701 is the only option that can take 8V and can force PWM. Do you have any other solutions?

    Thanks and Regards,

    Emilija

    TPS62230

  • 0 in reply to Emilija Zukauskaite
    TI__Expert 3645 points
    Hello,
    please have a look into this device TPS62056, especially if your input is up to 8V. You should be able to solder this package and it has forced PWM.
  • 0 in reply to Alfonso Furio
    Expert 1100 points

    Hi Alfonso,

    TPS62056 looks good but it has a low switching frequency of 850 kHz. I think I need at least 2 MHz switching frequency for wireless application. What do you think? Should I stick to TPS630701?

    Thank you.

    Regards.

    Emilija

  • 0 in reply to Emilija Zukauskaite
    TI__Expert 3645 points
    Hello,
    Unfortunately I don't have other device with similar specs and higher frequency in my portfolio. I don't support the TPS630701, but I will submit this thread to the right person.
  • 0 in reply to Alfonso Furio
    TI__Guru 58215 points
    Hello Alfonso,
    Thank you for looping me in.

    Hello Emilija,

    Let me summarize the requirements again, that I did not overlook anything:
    VIN = 3.5V to 8V
    VOUT = 3.3V
    IOUT = 500mA max.
    f >= 2MHz
    forced PWM

    With these requirements I recommend TPS63701 from our buck-boost portfolio which you are already using.

    I have 2 more questions to your design:
    1. What is the maximum VIN? You mention a 8V power supply, but I expect that it can go higher, correct?
    2. You mention a single LiIon battery and 3.5V as minimum VIN. Why are you discharging only to 3.5V?
  • 0 in reply to Brigitte
    Expert 1100 points
    Hi Brigitte,

    Yes, the requirements are correct.

    Vin max of 8V should be okay. We are using 6V solar panel and wouldn't expect the voltage to go higher than 8V.

    We are using 4.2V battery and it usually dies around 3.6V-3.5V so we want to cut off the supply and wait for the battery to charge rather than keep trying to power the device up.

    Originally I was looking for a similar part to LM3281 but bigger package so I could solder it. QFN is fine but not BGA. But the requirement for Vin max changed now to a higher voltage than 5V and LM3281 wouldn't work as it only accept Vin max of 5.5V.

    Thank you.

    Regards,
    Emilija
  • 0 in reply to Emilija Zukauskaite
    TI__Guru 58215 points
    Hello Emilija,

    Thank you for the information. From the buck-boost portfolio, TPS630701. If you need to discharge the output TPS630702 is doing this, but needs a resistor divider to set the output voltage.

    But please keep in mind to drive the EN pin actively if you want to shut down at 3.5V.
  • 0 in reply to Brigitte
    Expert 1100 points

    Hi Brigitte,

    It doesn't have to be a buck-boost converter it can just be a buck converter but I can't find any suitable IC for my application. Do you know any buck ICs that could work?

    Thank you.

    Regards,

    Emilija

  • 0 in reply to Emilija Zukauskaite
    TI__Guru 58215 points

    Hello Emilija,

    As I do not know the buck portfolio in detail, I cannot answer your question personally. But it seems that you already discussed with the appropriate team before the discussion with the buck-boost solution was started.

    As far as I understood the discussion, the problem is that with 3.5V input and 3.3V output buck converters normally do not switch anymore and as you need a fixed frequency, the buck converters seem not to fit. But to be 100% sure, I will again assign this thread to the buck team.

  • 0 in reply to Brigitte
    TI__Expert 3645 points

    Hello Emilija,


    I think we already discussed the suitable devices in our portfolio. We previously found a device matching your specs (TPS62056). I invite you to re-think about your requirements in terms of switching frequency. I will recheck my portfolio to support you, but which is the Vin that you need? (5V or 8 V)
    Can you also give me some info about your application and volume?

  • 0 in reply to Alfonso Furio
    Expert 1100 points

    Hi Brigitte and Alfonso,

    Thank you for your support.

    I will stick to TPS630701 as I'm already using it for 5V output and it works well. I will change it to 3.3V output.

    Vin could be from 3.5V to 4.2V from the lithium battery or 6-8V from the solar panel.

    The DC-DC application is to provide power to ESP32 module which includes Wi-Fi 2.4GHz, Bluetooth and Lora. At the moment we use Lopy4 which has LM3281 inside and ESP32 which has 6 MHz switching frequency but Vin max is too low and I can't solder BGA.

    Regards,

    Emilija

  • 0 in reply to Emilija Zukauskaite
    TI__Expert 3645 points
    Hello,
    I am going to close this post since it seems you will use TPS630701. If you need further support, you can open a new thread.