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TL760M33-Q1: pre-regulator for using linear regulator in high voltage

Part Number: TL760M33-Q1
Other Parts Discussed in Thread: TPS7A78

Hi,I want to use TL760M33-Q1 linear regulator between 10Vac-220Vac.(Variable voltage).I will use full bridge rectifier.How to use a pre regulator circuit?I only need 20ma.

  • Hi Tearlach, 

    After the rectifier, what's the DC voltage? In addition, what's your objective of having the LDO as a pre-regulator? 

    Jason Song

  • Hi Jason,My terminal voltage between (10Vac-220Vac).voltage is (10Vac-220Vac)mines(Bridge,forward voltage),after the rectifier.Example,
    Terminal voltage=200Vac,
    Dc voltage 200-(1,4)=198,4 Vdc (1,4 typical bridge forward voltage).
    I will use linear regulator as power supply for microcontroller and led.I need to take just 20ma from linear regulator.But,I have high voltage for input of linear regulator.To overcome this voltage,I need to pre-regulator.Maybe,I sould keep the linear regulator input constantly at 25 volts with pre-regulator.I need to a strong pre-regulator design.Can you help me?Or is there a pre-regulator circuit designed by TI firm for these works?

    Best Regards

  • Hi Tearach, 

    We actually released an AC LDO that may directly take an AC signal and provide up to 120mA of the load. Do you think this part may help with your situation? The part number is TPS7A78.

    Jason Song