sure,
this indicate that protection is activated for some reason.
First you will have to see if all voltages are ok , because there are some under voltage protections that can activate this lock.
check ,in relation to ground , if you have unless +5 volts an -5 volts at the front end of 2092.If you have less than 4,5 volts,ic protection activate.Then ,check if you have unless 11 volts,in relation to -b at vcc.
supposing all voltages are ok,try using mosfets with less qg,since this ic activates the protection if qg of mosfets are huge.Try irfb4019 or similar.
This ic is very sensitive to layout of pcb.Try to follow ir suggestion.
Pay attention to inductor caracteristics.Dont use any unkwon ferrite at inductor.Only type 2 is ok.Other option has to be carefully studied.You could send some pictures of pcb and the hole project.
this indicate that protection is activated for some reason.
First you will have to see if all voltages are ok , because there are some under voltage protections that can activate this lock.
check ,in relation to ground , if you have unless +5 volts an -5 volts at the front end of 2092.If you have less than 4,5 volts,ic protection activate.Then ,check if you have unless 11 volts,in relation to -b at vcc.
supposing all voltages are ok,try using mosfets with less qg,since this ic activates the protection if qg of mosfets are huge.Try irfb4019 or similar.
This ic is very sensitive to layout of pcb.Try to follow ir suggestion.
Pay attention to inductor caracteristics.Dont use any unkwon ferrite at inductor.Only type 2 is ok.Other option has to be carefully studied.You could send some pictures of pcb and the hole project.
How does qg influence protection activation? Isn't the OCP sensing the voltage across Rds-on?
It's Vds what is sensed, and it includes not only Rds-on drop but also the drop across drain and source lead inductances (4.5nH + 12.5nH respectively for TO-220) and layout inductances. During switching events, when current is rising (negative current falling during body diode reverse recovery), voltage drop on Ls+Ld may exceed 4V (it's proportional to current rise slope) resulting in false trigger if proper blanking is not applied.
When a MOSFET is turned on, Vds does not fall to just Rds-on drop instantaneously, there is a turn-on process with several parts. In the last portion of the process, Vds is already low, below 15V usually, and gate to drain ("miller" or "feedback") capacitance increases dramatically as Vds drops further (see datasheets). As a result, the last part of the turn on process is long, particularly for parts with high gate charges. In these circumstances, Vds sensing may trigger protections erratically if blanking time is not long enough.
When a MOSFET is turned on, Vds does not fall to just Rds-on drop instantaneously, there is a turn-on process with several parts. In the last portion of the process, Vds is already low, below 15V usually, and gate to drain ("miller" or "feedback") capacitance increases dramatically as Vds drops further (see datasheets). As a result, the last part of the turn on process is long, particularly for parts with high gate charges. In these circumstances, Vds sensing may trigger protections erratically if blanking time is not long enough.
Hi,Mr Gu,look my modules ,If you any question ,please connect me,I lived in HangZhou.
Sherly,here some Photo for you.
http://www.diyaudio.com/forums/class-d/155241-class-d-kits-bass-guitar-amp.html
Sherly,here some Photo for you.
http://www.diyaudio.com/forums/class-d/155241-class-d-kits-bass-guitar-amp.html
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