1N4148 is a switching diode with withstand voltage of 100V, current of 150mA and fast reverse recovery speed

1N5819 is a Schottky diode with withstand voltage of 40V and current of 1a. The forward voltage is reduced and the reverse recovery time is about 10ns. It is mainly used in high frequency circuits

1N4007 is an ordinary rectifier diode with withstand voltage of 1000V, current of 1a and reverse recovery time of Ms. it can only be used in low-frequency circuits

Difference between 1N4148 and 1N5819:

High frequency, low voltage and high current characteristics are the differences between 1N5819 diode and ordinary diode. It is widely used in switching power supply, frequency converter, driver and other circuits for high frequency, low voltage and high current rectification, freewheeling and protection diode.

1N5819 is characterized by super fast speed (low switching loss) and extremely low voltage drop (low voltage loss), but the withstand voltage is also low, usually less than 60V. It is suitable for low-voltage (< = 12V) switching power supply.

Ordinary diode has fast recovery speed, large voltage drop and high withstand voltage. It is suitable for high voltage (> 12V ~ 1000V) switching power supply.

1N4148 is a point contact small current rectifier with high speed, but the current is only 50mA. Another purpose of 1N5819 diode is voltage stabilization - using reverse characteristics. Therefore, when the withstand voltage is low and the current is not large, it can be considered to use a voltage stabilizing tube instead.

The reverse leakage of 1N5819 tube is a little larger. But the capacitance is small. Fast. But it's not as fast as 1N4148. After all, people's purpose is high-frequency detection, not rectification.

Differences between 1N4148 and 1N4007:

1N4148 and 1N4007 can be replaced with each other in case of ordinary small current (below 100mA, reverse voltage below 100V) and unimportant occasions,

1N4148 is a small current switch tube with 100V withstand voltage,