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Questions tagged [depletion-mode]

Anything related to depletion-mode devices (e.g. depletion MOSFETs, JFETs), i.e those semiconductor devices (largely FETs) whose output current (e.g. \$I_D\$) may be non-zero when the controlling signal (e.g. \$V_{GS}\$) is zero.

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How do I successfully drive this MOSFET for a dump load resistor with a wind turbine?

I am constructing an AC-DC Rectifier with dump load control for a wind turbine (see Schematic for info). The following use cases are required: Rectifier rectifies AC into DC and provides energy to ...
Jasper's user avatar
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5 votes
2 answers
221 views

Has anyone ever obtained a P-Channel Depletion mode power mosfet? [closed]

I cannot find any P-Channel Depletion mode mosfets at any supplier. I see this question from 10+ years ago: Where are the depletion PMOS transistors? But has ANYONE been able to source a P-Channel ...
NULL pointer's user avatar
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Tetrode versus Common Gate Depletion mode MOSFET

I've been looking at all the specification sheets for N-channel tetrodes. What is of particular interest is the old 3N213 by GE. Are all Tetrodes nothing more than dual gate (common gate) N-channel ...
user3078097's user avatar
1 vote
0 answers
54 views

Unicorn Mode PMOS For Hurricane Flooded Golf Cart Controllers

We have saltwater flooded golf carts after hurricane Ian. Their old 0-5k Ohm throttle pots are shot, and replacing them is very expensive. The new throttle systems can be fitted more cheaply, but ...
Elkrat's user avatar
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1 answer
111 views

How turn a transistor ON when the control signal is OFF

I am creating a light control circuit with a low-power tilt switch (>0.1A) to automatically turn lights on and off when the switch is tilted. When the switch is level, it is open, and I want the ...
Raddy's user avatar
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3 votes
1 answer
287 views

Alternative to depletion mode P-channel MOSFET based voltage limiter?

I find this voltage limiter circuit very simple and useful: simulate this circuit – Schematic created using CircuitLab To my surprise, neither Mouser nor Digikey have P-Channel Depletion Mode ...
HannesW's user avatar
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1 vote
1 answer
87 views

Are there any substitutions for depletion PMOS transistors?

I am currently building a low-voltage cut-off circuit. When the battery is under 10 V, the microcontroller should pull the battery power to ground which will blow the fuse with high current and cut ...
Terry's user avatar
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1 vote
1 answer
63 views

MOSFET depletion region

I was reading the answer from placeholder and re-posting his excerpts from an answer. I didn't understand the following points well: the channel has p-dopants in it which when the voltage is applied ...
Singh's user avatar
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1 answer
122 views

Can I bias a depletion mode FET with a diode?

I'm trying to work out how to bias a dual gate MOSFET that I'm working with. Its behavior is halfway between depletion and enhancement modes. That is, its ideal VG range is about -1.5V up to about 0....
Toby Eggitt's user avatar
3 votes
1 answer
185 views

Identifying / distinguishing between PIN photodiode and avalanche photodiode

Is there any way to determine whether an unidentified photodiode is a regular PIN photodiode or is an avalanche diode? The photodiode is part of a small scintillation detector unit.
Eric Slighton's user avatar
1 vote
0 answers
211 views

LED Driver IC to charge batteries

I would like to use the ZXLD1350 LED driver IC to provide constant current to some NiMH batteries to charge them. However the negative terminal of the LEDs go to an inductor instead of ground. My aim ...
JC123's user avatar
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Advice for P-Channel Mosfet in Depletion Mode

i want to be able turn off a led with a mosfet and a pushbutton. In order to do this i want the led to be in off state when voltage is applied to the gate of the mosfet. After researching for a while ...
abdussamed17's user avatar
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1 answer
74 views

MOSFET-enhancemement-depletion-n type-p type [closed]

Can someone please explain me the difference of n-channel enhancement, n-channel depletion and p-channel enhancement, p-channel depletion because I am confused. Correct me if I am wrong but the n-...
pj33's user avatar
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1 vote
1 answer
1k views

Normally closed mosfet circuit

I'm designing a battery charging circuit for a portable device. Conceptually it looks lik so: simulate this circuit – Schematic created using CircuitLab As a safety function, the circuit can ...
Sergi MF's user avatar
2 votes
1 answer
237 views

Schematic for input protection with NMOS? Does this really work?

I was reading an old schematic and found this and sketched it up; (see box in image "Some kind of protection") The closest thing to this schematic that I've been able to find, that could have briefly ...
user103776's user avatar
1 vote
1 answer
169 views

Universal voltage input using depletion mode N-FET - Advice

In an attempt to idiot proof a device I am designing that needs both 24V DC and 120V AC inputs for logic, I set out to create an input system that could handle either voltage going to a simple 3.3V ...
MadHatter's user avatar
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0 votes
1 answer
75 views

Switching power to a slave module without wasting power

I've got two circuit modules, let's call them master and slave. The master controls whether the slave is powered (5V and 3V3 rails). Both modules share the same power supply. The slave will be ...
BenAdamson's user avatar
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1 answer
511 views

Depletion Mosfet working as enhancement NMOS

The depletion mosfet can also operate in enhancement mode when the gate voltage is positive (say for depletion type NMOS). My question is : Will the Shockley equation be still valid in the ...
Ashik Anuvar's user avatar
-2 votes
1 answer
469 views

Need a P channel depletion MOSFET with continuous current of 2400mA [closed]

Can you guys recommend me some PFETs for Q2 in this circuit 1 (figure 2) that I can use to get continuous current flow of 2400mA? My segment current is 300mA, so I'm looking at 300mA X 8 = 2400mA for ...
MIWMIB's user avatar
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1 vote
1 answer
312 views

Capacitor problem using an NMOS inverter with depletion load

When Vin is low the enhancement type NMOS is off. That means the drain current of both transistor is zero, isn't it? If it is, then how will the parasitic capacitor charge? I'm not understanding! And ...
Enthusiast's user avatar
1 vote
1 answer
2k views

Depletion-mode P-channel MOSFET availability? [duplicate]

I need a P-channel depletion-mode MOSFET for a circuit I'm building. However, there is no model available in LTspice that I have found, nor is there any available that I have found to buy online. ...
Allenph's user avatar
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3 votes
1 answer
76 views

In depletion MOSFETs, what is the drain current value when \$V_{GS}\$ is zero?

When \$V_{GS}\$ is very negative \$I_D=0\$, whereas it conducts a little current when \$V_{GS}\$ is a little negative. What is the value of \$I_D\$ when \$V_{GS}=0\$?
ema's user avatar
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