Switching regulator that has a distinct characteristic of generating the output voltage always less than input voltage
Which kind of switching regulator has a distinct characteristic of generating the output voltage always less than input voltage where the variations in output voltage can be undertaken by adjusting duty-cycle of transistor?
a. Step- Up Regulator
b. Step-Down Regulator
c. Inverting Regulator
Correct Answer: b. Step-Down Regulator
The output voltage in step-down regulator mainly depends on input voltage and pulse-width. Pulse width refers to ON time of transistor.
With an increase in ON-time relative to OFF-time, charging capacity of capacitor increases by simultaneously increasing the output voltage & vice-versa.
Hence, a wide range of variation can be observed in output voltage by adjusting the duty-cycle ( the ratio of TON / T ) of the transistor by,
VOUT = Vin (TON / T)
where, the 'T' represents the period of ON-OFF cycle of transistor & has a reciprocal relative significance with the frequency in the form of T = 1 / f
Also, Total T = TON + TOFF & hence the ratio of TON / T is precisely known as 'Duty Cycle'.