8205A PDF

A are available at Mouser Electronics. Mouser offers inventory, pricing, & datasheets for A. 28 Apr This manual contains new product information. Fortune Semiconductor Corporation reserves the rights to modify the product specification. A Transistor Datasheet, A Equivalent, PDF Data Sheets. MOSFET. Parameters and Characteristics. Electronic Component Catalog.

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To answer your question about what the drain voltage will be relative to ground the battery’s negative terminalthere are a few cases:.

Dual mosfet A – lithium battery protection circuit – Electrical Engineering Stack Exchange

You need to read the datasheet of DWP: Sign up or log in Sign up using Google. Home Questions Tags Users Unanswered. This is assuming you measure in a “forward” direction from the BATT- terminal to the drains. Suggested to correct the circuit for simulation. Over current protection for a 1-cell battery and Remove over-current protection of battery protection circuit. As a few others have mentioned, the drains of that dual MOSFET will be pretty close to the same potential as the negative battery terminal.

When Vgs gets high enough Vds will drop below Vgs-Vth and the mosfet will go into the linear region. Hope this at least clears up how MOSFETs work and why someone would even want to put two back-to-back like in that battery protection circuit. Post as a guest Name. However, M1’s intrinsic diode would still be conducting!

protection ic 8205a

Because both source terminals of the two back-to-back MOSFETs are connected together, it’s really easy to put a positive bias on the gates as we can tie both gates together and drive them as one. Normally, the drain of a mosfet is connected to the positive.


Power MOSFETs have body diodes present within their structure, this is a by-product of how they bare designed and it not always a desired feature this being one of those times. Note that M2 cannot disconnect the battery during normal operation due to it’s internal parasitic body diode, and this is the reason why M1 is required in this orientation to block “forward” flow when off.

Atmega i think you confusion is that the active and saturation regions for a mosfet and bjt are opposite. I still don’t 2805a it. This is a basic lithium battery protection circuit, but looking at the dual mos-fet part of the circuit, It doesn’t make sense to me. It’s a A dual mos-fet, with its drain connected together and each of its source connected to the negative of the input and output.

A MOSFET Datasheet pdf – Equivalent. Cross Reference Search

If you flipped M2, a similar situation exists where the protection circuit loses its ability to protect against over-charging. Now that we’ve gotten some background info out of the way we can get to answering your question. Post Your Answer 8205z By clicking “Post Your Answer”, you acknowledge that you have read our updated terms of serviceprivacy policy and cookie policyand that your continued use of the website is subject to these policies.

The reason we use two back-to-back MOSFETs in this situation is because we want to make sure that we can completely block power from flowing in either direction when necessary which is a bit tricky with those pesky body diodes.

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Sign up using Email and Password. The drain voltage is only 825a when either. Alex 3 6. Another thing to understand is that when Vgs rises Vds falls.

I have read but not comprehend that wiki page many times. In this we may get wrong results. By using our site, you acknowledge that you 82005a read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

So the voltage at the combined drains will be a resistor-divider’s-worth above ground, say perhaps 0. To ensure that the battery can be completely isolated i. Dual mosfet A – lithium battery protection circuit Ask Question.

The circuit given by Alex to simulate appears to be wrong as it connects drain to source, while the device A under discussion has both drains shorted.

You can also read the two questions I asked about the same circuitry: And seeing as MOSFETs don’t care which way power’s flowing when they’re fully ON, this arrangement basically makes something which looks just like a relay. This turned into a much longer ramble than I expected and I may have missed a few things or used a few B-grade analogies. Atmega 1 8 Even if both MOSFETs were turned off, there is still a current path and the battery would continue discharging well past its safe discharge voltage.

With an increasing Vgs the mosfet turns on and as it turns on Vds decreases. Any more in either direction and one of the diodes would start conducting.