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mcp1703 voltage regulator

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devil6600

Full Member level 5
hi
can any one tell me how to calculate capacitance for mcp1703 voltage regulator?
i have tried reading datasheet (page 13-14) but unable to understand how its calculated. i need output to be 3V from a 6v battery.
thanks

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Data sheet says
• Stable with 1.0 μF to 22 μF output capacitance

If you use battery as source there is no ripple voltage.

Input C = 4.7µF
Output C = 4.7µF

if load current >100mA use output C 10µF
if load current < 20mA use 1...2.2µF

if load is higher frequency circuit f > 100kHz, connect 100nF capacitor ( f > 1MHz 10nF )
parallel to output capacitor.

Last edited:
devil6600

devil6600

Points: 2
thanks kak111
can you please tell me how do you calculated 4.7uF

Here is some calculation models
but they are for rectified power source.
In your case source is battery ie no ripple.

Power Supply Design

Power Supply Integrity

Most important function in this circuit is that capacitors make the power source
circuit act like short circuit for all ac-currents supplied to load circuit.
( from f = 0.......needed fmax. )
If load circuit see power source as Z= 0 ohms, in all load situations
output voltage gonna be stable.

devil6600

Points: 2