Detection method for varactor diode

Detection method for varactor diode

1. Discrimination between positive and negative poles: Some varactor diodes have a black mark on one end, which is the negative pole, and the other end is the positive pole. Some varactor diodes have yellow and red rings painted on both ends of their casing, with one end of the red ring being the positive electrode and the other end of the yellow ring being the negative electrode.diode

You can also use the diode mode of a digital multimeter to determine the positive and negative polarity of a varactor diode by measuring its forward and reverse voltage drops. When measuring the forward voltage drop of a normal varactor diode, the reading on the meter is 0.58~0.65V; when measuring the reverse voltage drop, the reading on the meter displays the overflow symbol "1". When measuring the forward voltage drop, the red probe is connected to the positive terminal of the varactor diode, and the black probe is connected to the negative terminal of the varactor diode.

2. To determine the performance, measure the forward and reverse resistance values of the varactor diode using the R × 10k range of a pointer multimeter. A normal varactor diode has both forward and reverse resistance values of ∞ (infinity). If both the forward and reverse resistance values of the tested varactor diode have a certain resistance value or are both 0, it is due to leakage or breakdown damage of the diode.