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The 1N4007 and the other diodes in the series are described as being a general purpose rectifier with a low forward voltage drop, low leakage current and high forward surge capability.

This device is the one with the highest reverse voltage rating, and therefore it is very widely used.

The 1N4007 is one of the diodes in the 1N400x series and it offers a reverse voltage capability of 1kV. These diodes have been available for many years and are still current devices, being manufactured by many companies, and being stocked by many main-line component distributors.

Applications for these diodes can include: full and half wave rectifiers, prevention of reverse polarity on devices and equipment, in protection circuits, etc.

Key details and performance parameters for the 1N4007 rectifier diode.

Explanation of major diode parameters

These are the main operational amplifier parameters that have been included in our list. There are others, but these help quantify the main elements of the performance of the regulator, but are normally deemed to be less important.

Please note, that the data given is the best estimate we can give within a tabulated summary of this nature. Parameters also vary between manufacturers. Electronics Notes cannot accept any responsibility for errors, inaccuracies, etc, although we do endevaour to ensure the data is as accurate as possible.

Notes and supplementary information

  •   Availability & sources

The 1N4007 is available from a number of stockists and electronic component distributors many of which are given in the table below.

1N4007 Component Distributor, Stock and Pricing

  •   1N4007 reverse voltage parameters

It is very important to understand the reverse voltage ratings for rectifier diodes as it is important not to exceed their maximum reverse voltage, especially where voltages are higher as the results of breakdown can be more catastrophic.

There are several circuits where these diodes are often used, namely a simple half wave rectifier, a split secondary transformer full wave rectifier and a full wave bridge rectifier.

Although other circuits may be used, these are probably the most important.

Half wave rectifier:

Take the case of the simple half wave rectifier. Here the incoming waveform reaches a peak which is 1.414 times or √2 times that of the RMS input waveform.

However the load is likely to have a smoothing capacitor and this will adopt the peak value of the rectified waveform, which is again 1.414 times that of the incoming waveform.

Although there will be some discharge of the capacitor, it is always best to assume this peak value.

This means that the diode will not only have a reverse voltage arising from the blocking of the incoming waveform, but aso that of the voltage from charge held by the circuit.

In other words the whole reverse voltage will be twice 1.414 times or 2.828 times the RMS value of the incoming waveform, i.e. almost three times the value.

The 1N4007 with its 1kV rating will provide sufficient reverse voltage capability for a huge number of circuit designs.

Two diode full wave rectifier:

The two diode version of a full wave rectifier is not so widely used these days as it reduces a centre tapped secondary winding on the transformer, but when used it is important to understand the maximum reverse voltage on the diodes used.

Looking at the circuit, one diode will conduct over one half of the cycle, and the other diode over the other half of the cycle.

Taking the case where the diode D1 is conducting, as the voltage from its half of the secondary starts to rise, so does the voltage in the other half. One diode, in this case will conduct, and the other diode, D2 will be reverse biassed.

The voltage will rise to a voltage Vp, the peak voltage from the transformer which is √2 times the RMS voltage. If a capacitor is placed across the load to act as smoothing, this voltage will be maintained, even if it has a small amount of ripple.

With the peak voltage across the load at the peak of the cycle, the diode D2 will see this potential at one end of the diode, and at the other, it will see the peak voltage in the other sense from its half of the transformer.

In other words it must block twice the peak voltage, i.e. 2 √2 times the RMS output voltage of the transformer.

Full wave bridge rectifier:

It is very important to ensure that the peak inverse voltage of the bridge rectifier, or individual diodes is not exceeded otherwise the diodes, in this case the 1N4007 could break down.

The reverse voltage rating of the diodes in a bridge rectifier is less than that required for the two diode configuration used with a centre tapped transformer, but even so the 1N4007 is an ideal choice for many circuits.

If the diode drop is neglected, the bridge rectifier requires diodes with half the PIV rating of those in a centre-tapped rectifier for the same output voltage. This can be another advantage of using this configuration.

The maximum reverse voltage across the diodes is equal to the peak secondary voltage V_sec because over one half cycle the diodes D1 and D4 are conducting and the diodes D2 and D3 are reverse biassed.

Assuming perfect diodes that have no voltage drop across them - a good assumption for this explanation. Using this, it can be seen that points A and B will have the same potential, as will points C and D. This means that the peak voltage from the transformer will appear across the load. The same voltage also appears across each non-conducting diode.

As these circuits will often be connected to mains of the line power source, there could be transients that are seen on top of expected reverse voltages.

It is therefore wise to select a diode with a high reverse voltage rating like the 1N4007 to provide a good margin. For some applications, diodes with a V_R rating of at least four times the peak voltage from the transformer are chosen.

  Written by Ian Poole .
  Experienced electronics engineer and author.