Antiparallel (electronics)

This article has multiple issues. Please help improve it or discuss these issues on the talk page. (Learn how and when to remove these messages) You can help expand this article with text translated from the corresponding article in Spanish. (July 2019) Click [show] for important translation instructions. Machine translation, like DeepL or Google Translate, is a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Consider adding a topic to this template: there are already 1,006 articles in the main category, and specifying|topic= will aid in categorization. Do not translate text that appears unreliable or low-quality. If possible, verify the text with references provided in the foreign-language article. You must provide copyright attribution in the edit summary accompanying your translation by providing an interlanguage link to the source of your translation. A model attribution edit summary is Content in this edit is translated from the existing Spanish Wikipedia article at [[:es:Antiparalelo]]; see its history for attribution. You may also add the template {{Translated|es|Antiparalelo}} to the talk page. For more guidance, see Wikipedia:Translation. This section is missing information about anti-serial circuits in electronics, ideally put in a separate article.. Please expand the section to include this information. Further details may exist on the talk page. (July 2019) This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Antiparallel" electronics – news · newspapers · books · scholar · JSTOR (July 2019) (Learn how and when to remove this message) (Learn how and when to remove this message)

In electronics, two anti-parallel or inverse-parallel devices are connected in parallel but with their polarities reversed.

One example is the TRIAC, which is comparable to two thyristors connected back-to-back (in other words, reverse parallel), but on a single piece of silicon.

Two LEDs can be paired this way, so that each protects the other from reverse voltage. A series string of such pairs can be connected to AC or DC power, with an appropriate resistor. Some two-color LEDs are constructed this way, with the 2 dies connected anti-parallel in one chip package. With AC, the LEDs in each pair take turns emitting light, on alternate half-cycles of supply power, greatly reducing the strobing effect to below the normal flicker fusion threshold of the human eye, and making the lights brighter. On DC, polarity can be switched back and forth so as to change the color of the lights, such as in Christmas lights that can be either white or colored.

Battery-powered lights, which are wired in parallel, can also create a simulated "chasing" effect by alternating the polarity for each LED attached to the string, and controlling the positive and negative parts of the cycle separately. This creates two "virtual circuits", with odd-numbered LEDs lighting on positive polarity and even-numbered ones on negative polarity, for example. By eliminating the need for extra wires, this reduces costs for the manufacturer, and makes the cords less bulky and obvious for the consumer to string on decorative items. On cheaper sets, this causes strobing and prevents any of the LEDs from getting to full brightness, since both polarities share the same wire pair and cannot be active at the same time, meaning each can only be on during its own half of the cycle. Better lights can adjust the duty cycle so that any unused "off" time on one polarity can be used by the other, reducing the strobing effect and making it easier to create color blends (such as orange, amber, and yellow from a red/green LED).

Antiparallel diodes are often used for ESD protection in ICs. Different ground or supply domains at the same potential or voltage may be wired separately for isolation reasons. However, during an ESD event across the domains, one would want a path for the high current to traverse. Without the antiparallel diodes in place, the voltage induced by the ESD event may result in the current following an unknown path that often leads to damage of the device. With the diodes in place the current can travel in either direction.

• Bidirectional LED
• Charlieplexing

• https://www.researchgate.net/post/Why_are_diodes_connected_anti-parallel_across_the_MOSFET_or_IGBT_in_Inverter_Module
• https://www.utdallas.edu/~torlak/courses/ee3311/lectures/lecture3.pdf
• https://ieeexplore.ieee.org/document/4159554/
• https://www.scientific.net/AMR.328-330.32