1N4007 Reverse Blocking Sweep

Application

This circuit shows how a 1N4007 rectifier behaves as reverse voltage is swept through the blocking region and into breakdown. It is useful for understanding reverse leakage, breakdown voltage, and why high-voltage diode circuits need current limiting.

Design Context

VREV drives the diode cathode through RLIM while the anode is tied to the return node. The simulation is a DC sweep of VREV from 0 V to 1500 V in 10 V steps, so the chart plots reverse current as the applied reverse voltage increases. RLIM is 1 MOhm and limits current once the diode approaches breakdown.

Expected Behavior

At lower reverse voltages, Irev should remain very small because the 1N4007 is blocking. As the sweep approaches the model breakdown region near 1 kV, Irev should rise sharply. Above breakdown, most of the additional source voltage is dropped across RLIM, limiting the current instead of allowing an uncontrolled short.

Key Values

• VREV sweep: 0 V to 1500 V in 10 V steps.
• RLIM: 1 MOhm current limiter.
• Irev: measured diode reverse current.
• 1N4007 model breakdown voltage: 1 kV.

Suggested Experiments

• Narrow the sweep around 900 V to 1100 V to inspect the breakdown knee more closely.
• Increase or decrease RLIM to see how the limiting resistor controls breakdown current.
• Compare this circuit with a lower-voltage diode model to see how breakdown rating changes the curve.

Featured Component

The 1N4007 is the rectifier diode under test. In this schematic its cathode is driven positive relative to its grounded anode, showing the reverse-blocking behavior and transition into breakdown that define its high-voltage rectifier role.