Synchronous rectification

The characteristic of the synchronous rectifier circuit
is high efficiency.
FP5139 is used to generate a PWM wave.
OSC pin: generates an oscillation frequency through an external RC, corresponding to the frequency of the output PWM.
FB pin: is a comparison terminal, which can be used to adjust the output voltage
EG2104
MOS tube driver chip
It can generate two PWM waves to drive two MOS
chips. Power supply voltage: 2.8V-20V
input signal and output signal. Logic truth table:
synchronous rectification
. The synchronous rectification circuit uses power MOSFET with extremely low on-state resistance to replace the rectifier. Diodes can greatly reduce the loss of the rectifier, improve the efficiency of the DC/DC converter, and meet the needs of low-voltage and high-current rectification.
To put it simply,
MOS is used instead of the rectifier diode.
Since the MOS dynamic resistance is small, the loss on the rectifier diode is reduced.
BOOST is equivalent to the power supply and the inductor having the same polarity, thus achieving the purpose of boosting the voltage. When the MOS is disconnected, the filter capacitor is used to supplement the voltage. Similar to a reservoir (that's how I understand it)