The iconic 1N4001 is a small semiconductor diode designed for AC to DC conversion in a power supply. These small 1 A diodes (average forward current) are designed for rectifier service in 50 and 60 Hz systems. A single diode may be used for a half-bridge rectifier while four independent diodes may be used in a full-bridge rectifier as shown in Figure 1. The family includes the 1N4001, 1N4002, 1N4003, 1N4004, 1N4005, 1N4006, and 1N4007. These diodes have a reverse voltage rating of 50, 100, 200, 400, 600, 800, and 1000 VDC respectively.
The 1N4001 family is over 60 years old. It’s a design staple and is often one of the first diodes used in an education setting. In fact, the term “full-bridge rectifier” and 1N4001 are nearly inseparable.
This brief article explores the past, present, and future of the diode family. It also includes a set of frequently asked questions.
Figure 1: Image of a 1N4004 full-bridge rectifier circuit as used in an older wall mount power supply.
Tech Tip: The 1N4001 family is designed for relatively low frequency operation. It is useful for 50 and 60 Hz line operated equipment, but unsuitable for modern switched mode power supplies that often operate at frequencies in the 50 kHz range.
History of the 1N4001 family
The 1N4001 family has roots back to the late 1950s and early 1960s. This was an extraordinary period of development in physics and material science when high performance silicon semiconductors replaced the short-lived Germanium devices. Groundbreaking manufacturing processes, including physicist Jean Hoerni’s diffusion and masking allowed diode and transistor structures to be grown on one side of a silicon wafer. This set the stage for the integrated circuit and powerful processors used today.
Sadly, the 1N4001 diode family history appears lost in the whirlwind of innovation. The marketing focus is placed on the glamorous transistors that were developed in the same era such as the high-speed double diffused epitaxial star 2N2222.
We can say that the 1N4001 family burst upon the scene in the early to mid-1960s. For example, it is unceremoniously listed in Motorola’s 1965 Semiconductor Manual. This was an interesting time as the literature shows vacuum tube design side by side with transistor equipment. The rectifiers are shifting from selenium to silicon.
Future of the 1N4001 family
Today the humble 1N4001 family is a cornerstone of electronics design. This fact is reflected in DigiKey stock as there are millions available for immediate shipment. They truly are as common as jellybeans in a jar. They are readily available with cost as low as $0.10 each when ordered in quantities of 100.
Recent trends favor the use of switch mode power supplies. Elimination of the large power transformer (Figure 1) reduces weight, initial material consumption, and long-term energy consumption. This has displaced the conventional wall mount power supply featured in Figure 1.
Miniaturization trends have also reduced the number of 1N4001 diodes. Discrete diodes are often replaced with a bridge diode containing four diodes in a common package. For example, the bridge DF1506S may be preferred to four independent 1N4005 diodes.
While there has been a decline in use, we can expect the 1N4001 family to be available for many years into the future. Recall that they may be used for other applications including flyback voltage for relays.
1N4001 family FAQs
This section contains the frequently asked questions for the 1N4001 family. Please leave your questions below if you would like to expand this list.
How can 1N4001 family members be identified within DigiKey?
By definition, jellybean semiconductors are common components available from multiple vendors with competitive cost points. They often include variants reflecting the change in technology from the original lead solder devices to ROHS-compliant and the latest surface mount devices.
The best way to search for 1N4001 family member is to use two keywords. For example, “4004 diode” returns the original DO-41 axial parts along with a variety of modern surface mount components including the SMA.
What is 1N4001 used for?
The 1N4001 family is primarily used for rectification of AC into DC. A typical example is a low power converter where a transformer is first used to step down the 120 VAC (American) 250 VAC (European) voltage. A pair of rectifiers is then used to convert the AC to DC followed by a filter capacitor or inductors. Figure 1 shows a capacitor used as the filter capacitor.
Another common application is flyback voltage suppression. A diode is installed in parallel with a relay coil. When the coil is deactivated, the diode conducts preventing what would have been a high voltage spike.
What is the difference between 1N4001 and 1N4007?
Members of the 1N4001 family are all rated to deliver 1A. Family members differ in their ability to withstand a voltage in the reverse bias condition. The 1N4001 is the least capable member with a 50 V blocking voltage, while the 1N4007 is the most capable with a 1000 VDC blocking voltage.
Can I use 1N4148 instead of 1N4001?
The 1N4148 (related to the 1N914) and 1N4001 serve different purposes. The 1N4148 is a small signal diode designed for moderate speed switching while the 1N4001 family are designed for rectification.
While the 1N4148 and 1N4002 have the same reverse voltage rating, the current and power ratings are different. The 1N4002 has a larger die capable of surviving a single cycle surge of 30A. Also, the heavy gauge wire associated with the 1N4002 is better able to dissipate heat. While the substitute may work in the short terms, long term reliability is likely to suffer.
The 1N4002 is unlikely to work in a 1N4148 application as the 1N4002 rectifier is relatively slow.
Can I replace the 1N4001 with a 1N4007?
Yes, higher numbered family members may be substituted for lower numbered family members. Consequently, a 1N4007 (1000 VDC reverse) may be substituted for a 1N4001 (50 VDC reverse) diode.
Substitutions in the opposite direction are not allowed. A 1N4001 used in place of a 1N4007 will result in unreliable equipment operation. While the equipment may operate for a short period of time, the diode(s) will likely experience a high voltage breakdown with destructive results. This could include tripping a circuit breaker, opening a thermal fuse, or even destruction of the transformer.
What is the rating of 1N4001?
The rectifiers may be classified across three dimensions:
-
All members of the 1N4001 family share a 1A current capacity with the ability to withstand a non-repetitive current of approximately 30 A.
-
The 1N4001, 1N4002, 1N4003, 1N4004, 1N4005, 1N4006, and 1N4007 have a design maximum reverse voltage of 50, 100, 200, 400, 600, 800, and 1000 VDC respectively.
-
The maximum power dissipation may be estimated as the product of maximum current and forward voltage. For example, at a low temperature, the diode’s forward voltage may be 1 VDC for a 1 VDC current. The maximum power dissipation is therefore about 1 W.
Consult the datasheet for additional metrics such as speed and capacitance. As a rule, these other parameters are not critical for a slow rectification system.
Parting thoughts
The 1N4001 family is a strong member of the Jellybean semiconductor club. It’s still popular after 60 years of service. While there has been a decline in the linear wall-mount power supply once dominated by the 1N4001 family, they remain relevant for legacy designs, education, and relay flyback voltage suppression.
How many of these diodes were included in your first circuit design?
Please share your experience with this popular device.
Best wishes,
APDahlen
Related Information
Please follow these links to related and useful information:
About this author
Aaron Dahlen, LCDR USCG (Ret.), serves as an application engineer at DigiKey. He has a unique electronics and automation foundation built over a 27-year military career as a technician and engineer which was further enhanced by 12 years of teaching (interwoven). With an MSEE degree from Minnesota State University, Mankato, Dahlen has taught in an ABET-accredited EE program, served as the program coordinator for an EET program, and taught component-level repair to military electronics technicians. Dahlen has returned to his Northern Minnesota home and thoroughly enjoys researching and writing articles such as this.