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Original question:

which is best Alternative for LMZ34202

which is best Alternative for LMZ34202

Natesh kannan S
Intellectual 270 points
Other Parts Discussed in Thread: LMZ34202, LMZM33604, LMZM33606, LM2596, TPS563208, TPS56339

Dear Experts,

Currently working with GPS Tracking for Vehicle i am using lmz34202 for power supply, i want to replace the module with the best regulator

Note: that regulator support 4v to 20v input is enough 

current rating is greater than 3A,

the output voltage is 4.2V

the regulator must give a constant output voltage that doesn't swing or varied output depends on input voltage 

  • 0
    TI__Mastermind 47060 points

    Hi Natesh,

    The power module portfolio only uses internal buck regulators. This means that the input voltage must always be larger than the output voltage else it will enter dropout. Will your application require 4V input to 4.2V output? This may be an issue with using buck regulators in general. The output voltage will scale down linearly when the input voltage drops into dropout condition. 

    You may be interested in looking at the LMZM33604 or LMZM33606 for higher current options that may fit your application design.

    Regards,

    Jimmy 

  • 0 in reply to Jimmy Hua
    Expert 2300 points

    Hi Jimmy,

    thanks for your reply, my device need 4.2V constant output and input voltage range is min 5v to max 20v and the current rating is min 3A, i want to replace the LMZ34202 because that is make my BOM cost is so high that's why i want to change the module to best LDO for my requirements.

  • 0 in reply to surya
    TI__Genius 17905 points

    Natesh, for a min 3A application an LDO is going to be dissipating a lot of power for your input range and output voltage. What is the max current you need to supply?

  • 0 in reply to Kris F
    Expert 2300 points

    Hi  

    i am using GSM, BLE with GPS module, as per the Datasheet of GSM module needs closer to 2A for the GPRS transmission time, that's why i need greater than 2A so i ask 3A LDO for my design because that module has some other sensors. 

  • 0 in reply to surya
    TI__Genius 17905 points

    Surya,

    The approximate power dissipation in an LDO is going to be (Vin-Vout)*Iout. You can read more here. At the max condition of Vin=20V and 3A load that is (20V-4.2V)*3A = 47.4W dissipated in the LDO!

    Are you certain that you do not need a switching converter?

  • 0 in reply to Kris F
    Expert 2300 points

    Hi  

    if i give input power supply is 5V and 3A so here total Power of LDO is 15W so this is ok or not because if i choose Switching regulator like LM2596 that makes anonymous output to boost xl-tlv8544pir board that's why i choose  LDO, then kindly suggest best low-cost Switching regulator or LDO for my GSM/GPS module GSM module needs 4.2v >2A input, my AC(240)-DC adapter (China made) output is 5V 3A

    regards

    kannannatesh

  • 0 in reply to surya
    TI__Genius 17905 points

    Even at 5Vin to 4.2Vout 3A, an LDO will be dissipating about ~2.4W. Assuming a ThetaJA of 33degC/W (based on parts I see in parametric search), the LDO will have a temperature rise of ~80C above ambient. Depending on ambient temperature in your system, this may be too much temperature rise and may push the junction temp of the device above its maximum allowed temp. You may also have a system requirement to keep component temperatures below an allowed limit. So consider these factors when deciding if you can use an LDO. 

    To search for a switching regulator solution that meets your requirements, I suggest trying WEBENCH Power Designer. Enter your input and output requirements and it will show complete solutions with estimated solution cost so you can compare different options.

  • 0 in reply to Kris F
    Expert 2300 points

    Hi  

    thanks for the suggestion and i have to choose TPS563208DDCR buck converter for my requirements, is it correct selection or wrong

     

  • 0 in reply to surya
    TI__Genius 17905 points

    Did you need to support up to 20V input? TPS563208 is max 17V input and Section 9 of its datasheet recommends using only for applications with max duty cycle of 75%. 4.2Vout from 5Vin would exceed this (4.2/5 = 84%).

    In WEBENCH Power Designer, enter the full input voltage range (5 to 20V?), output voltage (4.2V) and maximum current (3A) you need in your application. Entering those requirements in the tool, I see a TPS56339 solution as the lowest estimated BOM cost solution. Take a look and compare different options to see which would work best for you based on estimated cost, efficiency, solution size, etc.

  • 0 in reply to Kris F
    Expert 2300 points

    Hi  

    thanks for Awesome analysis answer and i also design the power supply from ti power designer i have shown in below then i can use 12v adapter for TPS563208 input so kindly clear my doubt about can i use this design for my GSM/GPS based module because of that GSM/GPS module consume related to 2A at transmission time

    regards

    kannannatesh

  • 0 in reply to surya
    TI__Genius 17905 points

    Hi kannannatesh, TPS563208 looks like a good choice to me. -Kris

  • 0 in reply to Kris F
    Expert 2300 points

    Hi  

    thanks for suggestion