• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 1 answer
  • Subscribers 64 subscribers
  • Views 957 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

LDO for use in car

mahdi shojaei
Intellectual 305 points
Other Parts Discussed in Thread: TPS7A53-Q1

Hi every one ,

i searching TI for type of LDO regulator for power supply of my board that use in car and supply from car's battery .

my board have micro controller and GSM module and 12 v , 3A input power .

we all know power supply of car have lots of noise so any body can suggest me a LDO, circuit and document for design a power circuit that use from car's battery.

thank you

  • 0
    TI__Guru 55940 points
    Hi Mahdi,

    I see that your input voltage is 12 V and it sounds like you will have a load current of up to 3 A. What is the output voltage that you are looking for?

    One thing to keep in mind is that LDOs are power dissipative devices. Due to your high current requirements, you may need to step down the 12 V input to a lower rail before the LDO in order to remain within the operating junction temperature range of an LDO.

    If your output voltage is 5.15 V or below, please consider TPS7A53-Q1. This LDO has high PSRR and low noise; however, you will need to step down your 12 V input before the LDO in order to be within the input voltage range and operating temperature range of this LDO.

    Very Respectfully,
    Ryan
  • 0 in reply to Ryan Eslinger
    TI__Expert 7035 points

    Ryan is correct the recommended LDO would be the TPA7A53-Q1, but you will need to use a buck converter to first regulate the input to 5V (i am assuming that you are regulating a voltage between 3.8V-4.2V). Here is a link to the application i think you are referring to. This link will give some recommendations on what parts are typically being used for the buck converters in these systems.

    Let me know if there is anything else we can help you with.

    Regards,

    Mark

    [Edited to fix link]

  • 0 in reply to Ryan Eslinger
    Intellectual 305 points

    Hi Ryan , thank you for advice 

    my board need 2 type of voltage 6v and 3.3 and sum of current nearly 3A . 

    exactly i think for step down my input voltage to 5 or 6 then use LDO but cost is important for me is possible step down voltage with inexpensive way?

    thank you Ryan .

  • 0 in reply to Mark Sellers
    Intellectual 305 points
    Hi Mark first thank you for advice and document send for me , i think so also reply for Ryan to step down voltage before , you right my need voltage ( if use separate LDO for GSM module i need 6 v ) you said ,
    and could you send me a link again ( that's not exists) ,
    and could you guid me(document, part number of device , ...) to use or design buck converter because i new with it
    thank you so much Mark.
  • 0 in reply to mahdi shojaei
    TI__Guru 55940 points

    Hi Mahdi,

    You will need to keep in mind that LDOs are power dissipative devices.  From my understanding of your system you are looking at a large headroom (Vin - Vout) at high current (3 A).  It is likely that you will need to use a switching regulator to more efficiently step down the voltage before using an LDO such as TPS7A53-Q1.

    Mark updated the link in his post which I have also provided below.  This site contains several resources such as recommended parts, block diagrams, and even reference designs that you can use as you design your application.

    Very Respectfully,

    Ryan