Looking for a DC- DC regulators 5V-4.2V and 2.5 Amps

[gravi]

DC- Dc regulators

hi
Im searching for dc-dc regulator whose characteristics are given below

Input - 5Volts
Output - 4.2Volts
current - 2.5 Amps

Any suggestions?

Thanking you,
Ravi

 

[cyber1]

Re: DC- Dc regulators

sorry wrong upload

 

[max0412]

Re: DC- Dc regulators

I'm assuming you need good accuracy ( a series diode wont cut it),in which case you should look at LDO's.

Heres just one example.

http://www.micrel.com/_PDF/mic69502.pdf

 

[wichayen]

DC- Dc regulators

You can use combinition of transistor and zener diode to solve this problem. By using common emitter circuit and use Zener diode to bias Base of transistor. Output voltage = Vz-Vbe(sat)

--------------- >--------------
R \_/
l l
Input --------- Output
Z
l
-----------------------------------

 

[nguyennam]

Re: DC- Dc regulators

max0412 is right, this case, the LDO voltage regulator with high current capability is the most wanted - simple and efficient.

In case you do not need an exact 4.2V output, you can use a high power rectifier (maybe Schottky with lower drop-out than a standard) in series with the load.

wichaen - your solution is useless, how can you choose the zener and its resistor for this circuit? On the other hand, choosing the right series transistor is not easy.

nguyennam