Hi everyone
just a little question for Fredos
with no load, the amp has sometimes trouble to start...
maybe because of the feedback loop : loudspeaker is part of the output filter ;-)
I think it's normal (amp with no load isn't a usual way to do !!)
just a little question for Fredos
with no load, the amp has sometimes trouble to start...
maybe because of the feedback loop : loudspeaker is part of the output filter ;-)
I think it's normal (amp with no load isn't a usual way to do !!)
How do you take care of the gate voltage supply for the high side FET? Maybe your schematic requires grounding through the load in order to transfer charge to this supply.
Hi Zilog,
Supply of the upper fet is made by bootstrap diode and capacitor through the load you're right !
Supply of the upper fet is made by bootstrap diode and capacitor through the load you're right !
Hi
Isn't 4Vpp at 250kHz a bit too much? Is this because of series resistance of filter cap in output filter?
Isn't 4Vpp at 250kHz a bit too much? Is this because of series resistance of filter cap in output filter?
Hi luka,
filter corner frequency is around 25kHz, and triangle wave is 250kHz
so one decade away...
LC filter is second order so 40dB/decade attenuation
So fundamental amplitude of output pre filter square wave is divided by 100 (40 dB)
so it should be around 2Vpp (instead of 4vpp).
DC bus voltage is +/-82V at idle
and +/- 74V at max power 4 ohms load
filter corner frequency is around 25kHz, and triangle wave is 250kHz
so one decade away...
LC filter is second order so 40dB/decade attenuation
So fundamental amplitude of output pre filter square wave is divided by 100 (40 dB)
so it should be around 2Vpp (instead of 4vpp).
DC bus voltage is +/-82V at idle
and +/- 74V at max power 4 ohms load
Hi alexclaire
- Can you also tell me why is D8 (mur120) placed between pin2 and 5 of IR
- Are pin3 and 4 of 4070 floating?
And could you point me to thread where I could read about 555 current limiter cos I didn't find anything but just mentioning it
- Can you also tell me why is D8 (mur120) placed between pin2 and 5 of IR
- Are pin3 and 4 of 4070 floating?
And could you point me to thread where I could read about 555 current limiter cos I didn't find anything but just mentioning it
Hi Luka,
D8 (MUR120) is just here to prtotect the mosfet driver (IR2113)
it acts when Vs tends to become lower than -Vcc (in case of capacitive load)
yes pin 3 and 4 of 4070 are not connected...
D8 (MUR120) is just here to prtotect the mosfet driver (IR2113)
it acts when Vs tends to become lower than -Vcc (in case of capacitive load)
yes pin 3 and 4 of 4070 are not connected...
hi luka
don't think are necessary
gonna change output stage:
gonna put diodes in serie with mosfet and one anti parallel to prevent bodydiode current flow
mosfet die when high dv/dt or di/dt because body diodes are too slow
don't think are necessary
gonna change output stage:
gonna put diodes in serie with mosfet and one anti parallel to prevent bodydiode current flow
mosfet die when high dv/dt or di/dt because body diodes are too slow
Hi alexclaire
Do you really think diods in series is necessary, coz you would need big diods, put them on heatsink. If it without for you now and without destruction of fets I won't them in.
Do you really think diods in series is necessary, coz you would need big diods, put them on heatsink. If it without for you now and without destruction of fets I won't them in.
alexclaire said:like this
Crest CD3000 schematics distributed by me are now seems to be everywhere ....😉
A much more promising device
Check This Out
www.microsemi.com/datasheets/APTM20AM10STG-Rev3.pdf
Series Schottky Silicon Carbide Diode + Anti Parallel Fast Recovery Diode + NTC+ 200V 100A Mosfet in HalfBridge all in one isolated package and also low EMI radiation
makes this device an ideal for high power Class-D Audio amps...I am going to order these for sample evaluation....
Kanwar
Check This Out
www.microsemi.com/datasheets/APTM20AM10STG-Rev3.pdf
Series Schottky Silicon Carbide Diode + Anti Parallel Fast Recovery Diode + NTC+ 200V 100A Mosfet in HalfBridge all in one isolated package and also low EMI radiation
makes this device an ideal for high power Class-D Audio amps...I am going to order these for sample evaluation....
Kanwar
Attachments
Hi,
Hmmm... I wouldn't say ideal.
Check capacitances (input capacitance: 14nF) and the diodes characteristics...
Not really suitable output device for class-d amp.
I'd rather use simple high power mosfets. There are many good devices on the market.
The choice is yours!
All the best,
PS.: I'm really courius about the amplifiers that manufactured by your company, I prefer studying hi-power technology. Shall you give us the web-address of your audio company?
makes this device an ideal for high power Class-D Audio amps
Hmmm... I wouldn't say ideal.
Check capacitances (input capacitance: 14nF) and the diodes characteristics...
Not really suitable output device for class-d amp.
I'd rather use simple high power mosfets. There are many good devices on the market.
The choice is yours!
All the best,
PS.: I'm really courius about the amplifiers that manufactured by your company, I prefer studying hi-power technology. Shall you give us the web-address of your audio company?
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