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# High Side Driver 100 Duty Cycle

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share|improve this answer edited Jun 9 '16 at 13:39 answered Jun 9 '16 at 13:14 Oleksandr R. 1,374514 1 There is also a minimum off-time, because the boot capacitor needs Connect with us All About Circuits Home Forums > Circuits and Projects > The Projects Forum > External Charge Pump For High Side MOSFET Driver Reply to Thread Discussion in 'The Consider first the case where the input PWM signal is steady low, at 0 V above ground potential. Just before turn-off, approximately 1 mA is flowing through L120 to supply the current needed to drop 2 V across R121, placing Q121 gate at its 1.6-V threshold plus about 0.4 http://tuiconverter.com/high-side/high-side-and-low-side-mosfet-drivers.php

If so this won't work. 17th September 2004,20:58 17th September 2004,21:01 #4 flatulent View Forum Posts Private Message View Blog Entries View Articles Advanced Member level 5 Join Date application notes at web sites such as international rectifier or fairchildsemi. Can run full duty all day. Why is it harder to compute nonce for a hash with a certain number zero prefixes than it is for any other hash? https://forum.allaboutcircuits.com/threads/external-charge-pump-for-high-side-mosfet-driver.29009/

## High Side Mosfet Driver With Charge Pump

Plain textNo HTML tags allowed.Web I wonder are there any other ways, which is "clean", to replace bootstrap. 20th September 2004,11:13 #12 wky View Forum Posts Private Message View Blog Entries View Articles Member level 2 The load I used on the output consists of about 6 feet (2 m) of wire going to a circuit-breaker panel and then another 6 feet of wire going to a

What's the logic behind it and how will be the circuit? This variation does not depend so heavily on a long “off” time to prepare for the next “on” transition. Analyze MOSFET Parameter Shifts Near Maximum Operating Temperature Informed Analysis Picks Better 555 Timer To Drive Power MOSFET I needed a good, fast, and cheap way to drive the high-side MOSFET 555 Timer Charge Pump Circuit When PWM voltage drops to ground, Q122 turns off crisply.

In practice the power dissipation is very low. High Side Mosfet Driver Internal Charge Pump Might look at zenering the +V of the 555 so I can up the voltage of the circuit, but first I'll sort out noise and back-emf protection. Probably just a wrong connection, but I replaced the circuit with my original voltage doubler but modified it to resemble DT92-4 (see attachment). now you need a lot of charge in the cap, and are given no time in which to replenish..

Ken, I don't know if this will help you but I found it researching my own problem. Floating Charge Pump Ic In turn, this requires the gate to swing from 0 V to well above the input voltage. Need to know if Vishnu, Shiva or Indra stopped Vishnuwanth's Tapasaya How plausible is a 'tilted axis' planet with a "south pole" constantly facing toward its star? Since the turn-on threshold of Q121 is about 1.6 V, this condition will occur with about 1.6 V across R121.

## High Side Mosfet Driver Internal Charge Pump

Hope it helps you.Click to expand... It is worth checking, of course, but will not pose a real problem in many application. –Oleksandr R. High Side Mosfet Driver With Charge Pump Figure 3 shows the turn-on waveform of the final circuit. High Side N Channel Mosfet Driver Circuit Once Q120 gate rises within a volt or two of VIn, the rise is relatively slow, but we don’t care about that because Q120 is already in cutoff, as its gate

more stack exchange communities company blog Stack Exchange Inbox Reputation and Badges sign up log in tour help Tour Start here for a quick overview of the site Help Center Detailed http://tuiconverter.com/high-side/high-side-low-side-gate-drivers.php So, the gate needs to swing only from the input voltage to about 10 V below the input. It turns on once, transfers charge to the FET gate at the transition, and then is only discharged by leakage current in the FET gate and self discharge of the capacitor. Ken Attached Files: Control Box - Ver 1.4B - Power.gif File size: 63.7 KB Views: 544 Last edited: Oct 28, 2009 #9 Like Reply Show Ignored Content 1Next > Loading... Bootstrap Circuit For High Side Driver

We can actually trade off a slightly slower turn-off (600 versus 400 ns) for a slight decrease in bill of materials (BOM) cost and parts count (L120 and D120), depending upon I found the attached circuit in a datasheet for a different FET Driver. http://www.irf.com/technical-info/designtp/dt92-4.pdf It's a charge pump circuit that allows continuous on time from a gate driver. my review here I guess what I am wanting to know is if I apply my original circuit, even just as a safeguard, is it the correct way to recharge the Bootstrap Cap (will

That much power is going to get pretty toasty very quickly, even with a decent heatsink. (Did you ever try to unscrew a 100-W incandescent light bulb while it’s on? Mosfet Charge Pump Circuit Starting with Q122 off and C122 discharged, we raise Q122’s gate to 3.6 V. There are many dedicated available MOSFET gate drivers, but I shun proprietary or single-source solutions.

## High-side and low-side FETs off) or will it only charge when the low-side FET is on (ie.When brake is applied)?

Steven P. In that case you would maybe drive to 12V gate to source, and your gate can drop until the flat on that curve at ~2.5V before the FET starts to turn cheap and easy. High Side Gate Driver Circuit In the “off” case, we have zero current and thus zero power dissipation.

Moises Altamirano Apple to Enter the Automotive Game as Siri Begins to Lag in Personal Assistant AI Is Apple going to go up against Waymo and Tesla in the autonomous car No, create an account now. Is it acceptable to ask a waiter to pay if a customer leaves without paying? get redirected here You won't really be able to recharge the bootstrap cap while your top FET is gated, not without another converter anyway.

Thanks, Ken IRF3711 MOSFET: http://pdf1.alldatasheet.com/datasheet-pdf/view/68150/IRF/IRF3711.htmlClick to expand... Recalling that an ampere is a coulomb per second, 10 mA requires 20 µs to add or remove 200 nC. Q122 then sinks 10 mA through its drain. This circuit provides a stable dc gate level squarely between the turn-on threshold and the absolute maximum of Q120 while dissipating only 10 mA in the quiescent condition.

therefore, good for DC/DC converters, but not good for motor drives. All rights reserved. PublishLog in or register to comment Home page Save RelatedInformed Analysis Picks Better 555 Timer To Drive Power MOSFETDec 04, 2013Analyze MOSFET Parameter Shifts Near Maximum Operating Temperature Mar 17, 2014What’s He is also active in Boy Scouts and other volunteer activities.

i could be wrong, but i think microchip dot com also has some app notes on this subject. At the instant of turn-off, Q121 turns fully on at 10 Ω with 10 V across it, so 1 A quickly drains off the Q120 gate charge to below the 6-V If there is a breakdown problem on the MOS Vgs, put a Zener or resistor between the gate and the NPN so that when the NPN is on, the Vgs is Looking at the partial schematic of my first attempt, we can examine the static conditions (Fig. 1).

Thanks for the ideas and tips guys. Register Remember Me? Removing L120 and replacing it with a short results in the waveform of Figure 6. 6. Mr.Cube 18th September 2004,01:34 #6 Mr.Cool View Forum Posts Private Message View Blog Entries View Articles Advanced Member level 2 Join Date Jun 2001 Posts 664 Helped 94 / 94 Points

they have no idea how to do, but they go out and do it anyways. :) some things to keep in mind about bootstraping is that it is a "cheap and In practice, you may need to measure \$V_\mathrm{GS}\$ using an oscilloscope (obviously, exercise due care and use high-voltage probes if you are working at 500V) and experiment to determine the parameters, Remarkable coincidence, of course: that happens about the time we have removed 200 nC of charge from Q120’s gate. The upper trace is the 3.6-V PWM signal.