Use a digital source meter to measure the I-V characteristics of the diode, and analyze the connection method

1. Concept:

A diode is a two-port electronic device that supports the flow of current in one direction (forward voltage) and prevents the current from flowing in the opposite direction (reverse bias). Whether in research laboratories or production lines, I-V testing of packaged devices or diodes on wafers is required.

2. Digital source meter measurement advantages:

Diode I-V characteristic analysis usually requires highly sensitive ammeter, voltmeter, voltage source and current source. Programming, synchronizing and connecting all separate instruments is cumbersome and time-consuming, and requires a lot of rack or test bench space.

S-type digital source meter simplifies testing, reduces rack space, and becomes an ideal choice for diode characteristic analysis because it can provide current and voltage sources and measurements.

Three, diode I-V test

Diode parameter test requires that it can provide current and voltage sources and measurements in a wide range.

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Figure 2 shows the I-V curve of a typical diode, including forward zone, reverse zone and breakdown zone, as well as common test points, forward voltage (VF), leakage current (IR) and breakdown voltage (VR) . The forward voltage (VF) test involves providing a specified forward bias current within the normal operating range of the diode, and then measuring the resulting voltage drop.

Use a digital source meter to measure the I-V characteristics of the diode, and analyze the connection method

Leakage Current (IR) test determines the current level of diode leakage under reverse voltage conditions. The test is to provide a specified reverse voltage source, and then measure the resulting leakage current. In the reverse breakdown voltage (VR) test, you need to provide a specified reverse current bias source, and then measure the resulting diode voltage drop.

Fourth, the connection of the diode and the digital source meter

connection as shown

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Using 4-wire connection, the influence of lead resistance can be eliminated.

When the leads are connected to the diode, please note that the Force HI and Sense HI leads are connected to the anode of the diode, and the Force LO and Sense LO leads are connected to the cathode of the diode. Keep the connection as close to the diode as possible to eliminate the influence of lead resistance on the measurement accuracy.

When measuring low-level current (<1μA), it is recommended to use the triaxial coaxial connector and triaxial coaxial cable on the rear panel instead of the banana jack on the front panel.

The three-axis coaxial cable has a shielding function, which will reduce electromagnetic interference effects, which may interfere with readings. The figure below is a schematic diagram of the connection between the diode and the triaxial coaxial connector on the rear panel of the digital source meter.

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In addition to using triaxial coaxial cables, the diodes should also be placed in a metal shielded box that is protected from light.