Part Number: TAS5611A
We are using the TAS5611A (X2 to drive a dual voice coil driver, 2ohms per coil) & we have based the design on TI’s Typical Differential (2N) PBTL application with BD Modulation filters (also please note we now have INPUT_D going directly to ground)
We are finding that the TAS5611A is failing shortly after 5-10min into a 2ohm resistive dummy load & at 100Watts (after fault - 12V VDD line is shorted to ground within the device)
We also have the TI EVM board (TAS5611PHD2EVM) & have noticed that on the schematic page you have in a boxed area a note on “3ohm Load Operation” :
1) Mount Schottky diodes D24, D25, D26, D27
2) Change ROC = 22Kohm (R12)
Throughout the TAS5611A Data-sheet these above changes are not mentioned when “loads of 3ohm” (or is it <= 3ohms) are used. We want to know if we need to fit these Schottky diodes & change the ROC value accordingly to prevent the device from failing?
Can you please also suggest a part for these Schottky diodes if needed?
EVO SUB TAS5611 application.zip
Are you using two separate TAS5611 devices on the same speaker?
For the resistive dummy load case, are you sure the load is maintaining 2Ω at the 100W power level? We use load resistors here too and need to make sure that the resistor can support the power level we are pushing to it. A 100W resistor will often appear as less than it's rated resistance when too much power is pushed to it.
12V VDD shorted: Are you measuring this on board? In other words, could it also be that other nodes connected to "+12_a" are shorted to GND?
Can you send us the model numbers of your Output inductors and 680nF to GND?
I see a Capacitor to GND on INPUT_D to GND, this should be tied to GND directly, any reason for this?
I would suggest using the Schottky diodes and 22k.
In reply to Adam Sidelsky:
In reply to Harry Parsons:
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