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Questions tagged [body-diode]

The diode between drain and source in MOSFETs, formed by the PN junction between source and drain. This intrinsic diode is the reason MOSFETs can block current in only one direction.

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MOSFETs longevity & efficiency: On-state + act of turning on VS body diode. Which state impacts lifetime/longevity more? Which is more efficient?

So if you have a back to back MOSFET pair (drain touching drain or source touching source) in series, and you want to conduct current in one direction. You have two options starting from a state where ...
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Is m called the grading coefficient and equals to 1/2 or 1/3 in the following question?

The following is an example from Digital Integrated Circuit. Consider the following silicon junction diode: \$C_{j0}= 2 \times 10^{-3} F/m^2\$, \$A_D = 0.5 {\mu m}^2\$, and \$ \phi_0 =0.64 V \$ A ...
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Can you use a diode to cancel the body diode of a MOSFET?

From what I understand, MOSFETs inherently have a diode between the source and drain known as a body diode. If I were to use an nMOSFET as a low side switch, would it be bad to have a diode between ...
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Role of the body diode in a solid state relay

The solid state relay with MOSFETs connected back-to-back (source-to-source) is claimed to work by the mutual action of the body diode according to this website, and this TI paper. However, I had been ...
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VSD to ISD graph of MOSFET

I want to compare two graphs provided in datasheets of two MOSFETs. Could anyone please explain what we can conclude if we compare both graphs? Which device has the better forward voltage drop of the ...
Alison's user avatar
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What is a "Body dragger" in this load switch IC?

I am studying a white paper from Intersil/Renesas for a load switch IC ISL7x061SEH PMOS and SL7x062SEH NMOS. In the chips block diagram I see a block called "body dragger" that I don't ...
ztan's user avatar
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Does body diode reduce MOSFET switching loss in a power converter?

In power converters, it is common that MOSFETs are fed a PWM signal to have cyclic switching. Part of the power is lost in the process. Does the body diode reduce this loss? It seems most power ...
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Can I use MOSFETs as diodes in a battery backup circuit? [duplicate]

I'm trying to design a UPS circuit and I came across this: (source: idyl.io) It's a great idea, but I don't like the voltage drop due to the diodes. Can I use this reverse voltage protection circuit ...
GameFan's user avatar
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Pull negative battery to ground with MOSFET

I have an input signal that goes from +10 V to ground and I want use it to pull the node "A" to ground. The current will flow towards node "A" I was thinking using a NMOS, with in ...
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MOSFET body diode and inductive load

I want to open a solenoid electromagnetic lock using an IRFR024NPbF MOSFET. Datasheet: https://datasheet.lcsc.com/lcsc/1809062114_Infineon-Technologies-IRFR024NTRPBF_C2583.pdf Generally speaking, I do ...
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Can a MOSFET be used to switch between two supply voltages?

My goal is to programmatically switch between supply voltages (3.3V and ~2.6V) for a load. The 2.6V level doesn't need to be exact, +/- 0.2V is OK. I created the following circuit, which uses my MCU's ...
kirtan-shah's user avatar
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MOSFET - Body Diode protection

I want to build the cricuit like on the image below: V1 - Is a 14S LiPo battery(there would be fuse in real life between positive battery terminal and "BATTERY+" M1 - PMOS acting as a load ...
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MOSFET as bypass diodes in series of solar cells

I am building a small solar system of 5 solar cells in series (each about 5V 500mA in full load, total 25V 500mA) and want to maximize efficiency in case one cell is shaded. Traditionally there are ...
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Why do some analog circuits use a FET with shorted drain and source?

Why do some analog circuits use a FET with shorted drain and source? Depending of the type of FET, it may either act as a capacitor or a diode? It each case, why not just use a cap or a diode? Below ...
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Bidirectional level translator using N channel MOSFET

I'm using a n channel MOSFETa bidirectional level translator. The case when the body diode conducts the source end will be literally 0V or forward voltage of body diode, so the difference in voltage ...
Vignesh C's user avatar
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Freewheeling diode position [duplicate]

I have a pneumatic solenoid valve switching from IRF830 MOSFET. Solenoid valve connected to MOSFET by 2-3 feet long wire. It's necessary to use a freewheeling diode for this? What is the most ...
user_fs10's user avatar
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Forward diode characteristics not starting from zero Ampere

Why the current is not starting from zero, whats the diode characteristic when current is near zero? Reading the datasheet for N-channel 60V MOSFET, I encountered this source-drain characteristic of ...
Vaso's user avatar
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NMOS bidirectional variable resistor: How to increase body diode barrier potential?

I want to use an NMOS as a variable input resistor to an inverting amplifier. The source is connected to virtual ground and the drain is connected to the input. I need to accomodate both positive and ...
ElecNoob's user avatar
21 votes
3 answers
26k views

How should I understand the intrinsic body diode inside a MOSFET?

I know there is an intrinsic body diode inside all the MOSFETs, but I'm confused about the reason why it's there. I've searched the articles but can't find a good explanation for it. Can anyone use ...
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ORing mosfet controller with ability to switch off the load

My system is powered from a wall adapter and backup SLA battery. simulate this circuit – Schematic created using CircuitLab Since the voltage of the wall adapter is higher than the SLA, I have ...
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How can I map Body Diode datasheet params to simulink N-MOSFET model?

I would be interested on including the body diode effect of a NMOS transistor into the N-Mosfet that Simspace includes for electronics. However, the parameters that the Body diode in Matlab requires ...
ndarkness's user avatar
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Turning an NMOS with substrate terminal into a PMOS

Some NMOS's come with a substrate/bulk/body terminal so the "Source Voltage" referred to in literature then Substrate Voltage. Say then we short the gate to the drain and have the substrate take the ...
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I need some help understanding overshoot and ringing in MOSFET half bridges

From FDA75N28 datasheet: What I am having difficulty understanding are the reasons behind overshoot and ringing in V_DS. Now, to what I already know: The current that passes in an inductor cannot ...
rmarques's user avatar
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3 answers
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Where does the MOSFET body diode come from?

Where does the body diode in a MOSFET come from? I understand that its built in and an intrinsic part of the MOSFET. All illustrations of a MOSFET that I've seen depict the structure as two diodes ...
vini_i's user avatar
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8 votes
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MOSFET with *actual pin* for body

I have always thought that MOSFETs have four pins [see wikipedia], one of them connected to the body (i.e. substrate). However, when trying to order some, I have been completely unable to find any ...
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Extra Shottky Flyback Diodes on FET-based BLDC Motor Driver? [duplicate]

TL;DR: I have a FET-based BLDC motor driver design, and I need to decide whether to add discrete Shottky diodes in parallel with each FET for reliable and long-lived operation in an automotive-like ...
PKL's user avatar
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1 answer
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Body Diode of a MOSFET

So for some MOSFETs, specially with Power MOSFETs, the body diode is a flyback diode that (as far as aI can tell) can be conveniently added to the MOSFET's bulk as there already PN junctions (correct ...
Dehbop's user avatar
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Substrate Connection when driving a Bi-Directional Switch

I am very confused about the way the below circuit functions. Below is an excerpt from a research paper which shows two NMOS transistors connected such that the body diodes face each other back to ...
ashare's user avatar
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Use of MOSFETs body diode

I have an N-MOSFET array IC and I don't need to use all of them, but I do need to use a diode. Is it OK to use the body diode of one of the MOSFETs as a regular diode to decrease component count and ...
Cano64's user avatar
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3 votes
5 answers
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Replacing a Switch and Avoiding body diode conduction

I am trying to design a replacement for a 2:1 switch using FETs, which would be really easy if I didn't have to concern myself with the body diodes that are present on PMOS transistors. My scenario ...
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