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Pass Element For Ldo

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9 Threads found on edaboard.com: Pass Element For Ldo
The final determining factor current capability for a ldo is the pass element whether its a BJT or MOSFET.
Please help me! I need to design a ldo by cmos process, but its pass element is an offchip bjt. Please give me some suggestion or some paper of same type ldo. thanks.
Dear all, I am trying to design an ldo but I still did not understand why I should use a "pass element" like PMOS .....I think that even with an opamp and 2 resistor I can have the same behaviour...What do you think about?Why I should use this pass element?
*for transient : You can imagine the pass-element for very fast changes seen as a current source (as before EA catch-up the EA output voltage is constant ) & so varying the load can be seen by two points of views : 1) Varied resistance :for ex. load resistance varied from high resistance to (...)
what is the region of operation of pass element in ldo
Very Interesting. I am designing a ldo, & facing somehow similar problem in the error amplifier; the load is the pass-element whose gate node has an equivalent capacitance in the range of 60pF(may be more) & I need it to be fast in order not to get large spikes & dips & to have a gain not less than 40dB(for 1stage (...)
Here I have a dobut, when you design for the pass element what should be the nominal DC voltage or Vgs at the gate of the pass element i.e. PMOS in order to start the design ? TIA Raduga
If you embeded the PMOS on your chip , You must have margin for your design , The pass componet , Like PMOS must have 200mA ~300mA cability .
I want to use P-LDMOS for pass element of ldo because the on-resistance is lower than PMOS transistor. But the model of LDMOS for circuit simulation is a setback. who can help me? Thanks in advance. Just curious, why P-LDMOS has lower on-resistance compared with PMOS? Scottie