XL7005A vs XL7005

[budm]

Re: XL7005A vs XL7005

"V drops on the load is also about 2x the supply Voltage." very good!

PS: Ive traced the circuits, it like twins, two MOSFETs put together to increase current, and it only has two driver signals (Lo and Hi) (full bridge needs 4 driver signals.).



My home work.

provides characterization data of its half−bridge driver to show the maximum negative voltage the driver can safely operate with. To prevent the negative injection, it is the designer duty to verify that the amount of negative voltage pertinent to his/her application does not exceed the
characterization curve we provide, including some safety margin.

Confirm zero-voltage switching during all operating conditions
http://www.powerguru.org/the-half-br...cuit-revealed/

Half Bridge vs Full Bridge
https://cdn.badcaps-static.com/pdfs/...aa877cf64a.pdf

They sure do it in the cheapest way by cutting corner, no guarantee that the paralleled MOSFETs will conduct evenly, it needs to be done properly.


http://www.microsemi.com/document-po...rallel-mosfets
https://cdn.badcaps-static.com/pdfs/...14e4cae676.pdf
https://cdn.badcaps-static.com/pdfs/...e6d704a017.pdf
https://cdn.badcaps-static.com/pdfs/...239dca6d29.pdf

[capwizard]

Re: XL7005A vs XL7005

Ha ...Ha.... they did it like 1 plus 1 equal 2, Gate to gate, Drain to drain, Source to source, I thought it was a new design to save resistors.................

[capwizard]

Re: XL7005A vs XL7005

Should I buy STM32 Nucleo or the STM32F072 Discovery kit to read this firmware?..............

C'mon, STI, I know, you know the answer!

[sam_sam_sam]

Re: XL7005A vs XL7005

They sure do it in the cheapest way by cutting corner, no guarantee that the paralleled MOSFETs will conduct evenly, it needs to be done properly

What would a better way to use the MOSFETs to have a 10 amp load for long periods of time

[budm]

Re: XL7005A vs XL7005

What would a better way to use the MOSFETs to have a 10 amp load for long periods of time

You will have to study those links I gave, it may be simple to change the existing design, you may be able to get away by mounting the proper MOSFETs off the board on a proper heatsink and not paralleling them.
That board was made to keep the size and the cost down, that was their priority. I wonder how well it really handles the heavy load, just have to scarify one to find out, and probably need the accurate schematic too before doing modification.

[capwizard]

Re: XL7005A vs XL7005

"just have to scarify one to find out" .............. Do mine first..........

First preheat the PCB to 150 C, use 852D+ at 398F take out the four MOSFETs

PS: I use the popcorn heater as this Compaq Rework Station bottom part heater....

[budm]

Re: XL7005A vs XL7005

https://www.badcaps.net/forum/attach...2&d=1485442759
So the GATE DRIVE resistor R017 is 0 Ohms, the D7 Gate discharge diode is not use due to 0 Ohms resistor being used for one set of the MOSFET, there should be another set up for the other set of MOSFETs also..
See fig 17.
https://cdn.badcaps-static.com/pdfs/...bb5162a5d8.pdf

[capwizard]

Re: XL7005A vs XL7005

Over here! the other set of MOSFETs both Gates are connected with 10 ohm resistor then go to the IC(U02) pin(10).

[budm]

Re: XL7005A vs XL7005

That is strange, so they put 10 Ohms but also no diode for one MOSFET, 0 Ohm for another MOSFET. I wonder may be they put in the wrong resistor where it should be 10 Ohms not 0 Ohm. I would go with the application circuit of the IC data sheet instead of the maker of this board.

[capwizard]

Re: XL7005A vs XL7005

Yes, Isnt it unbalanced to drive MOSFETs?

[budm]

Re: XL7005A vs XL7005

It is supposed to be symmetrical. See the spec sheet of the IC post 27.

GATE resistor:
https://cdn.badcaps-static.com/pdfs/...daad08146b.pdf
http://irf.custhelp.com/app/answers/detail/a_id/215

[capwizard]

Re: XL7005A vs XL7005

Thank you, budm's information: MOSFET and IGBTS there is a parasitic capacitance between the gate and source/emitter and between gate and drain/collector. When a switch on voltage is applied to the gate, the gate to source/emitter capacitance will commence to charge up and the device will not start to switch until the gate threshold voltage is reached. As conduction starts then the gate to drain/collector capacitance starts to charge.series resistor values in the range 10 to 500 Ohms are typical.

a high dissipation mode, i.e while there is a significant voltage across their outputs there is also significant current flow. With higher drain/collector currents, particularly when switching inductive loads, there is a conflict in the requirement to switch the parts as quickly as possible but to not introduce unacceptably high levels of di/dt induced voltage spiking that could impede the switch on or off and in extreme conditions generate spikes that could irrepairably damage the HEXFET® MOSFET or IGBTS, particularly their gate insulations.

[budm]

Re: XL7005A vs XL7005

And that diode in parallel with the GATE resistor for GATE discharge should also be in place the GATE drive goes low.

[budm]

Re: XL7005A vs XL7005

BTW, so now you know why you just do not sub the MOSFET or IGBT without looking at the detail spec beside the Voltage and current rating.
Remember the Plasma TV that you sub the IGBT?

[capwizard]

Re: XL7005A vs XL7005

Look at this PRO. He posted at 2014

PS: No source code pretty much A dead meat. It is easier to write your own code (program).