TAS5630B: what will result in SD active?

Hi,

Please make sure customer's schematic is the same with the reference design on datasheet, and check below points,

1. When pulling the RESET# high, please check the voltage on VREG /VI_CM /C_startup/, and check if there is any switching on OUTx.

2. When pulling the RESET# low, please check voltage on SD#. It should be logic high.

3. If SD status changed with the replacement of a new device, please check if there is any problem with the soldering.

Regards,

Sam

Hi Sam,

thank you!

here is the feedback:

1. when reset high, VREG（~3.2V） /VI_CM （1.94V）/C_startup（3.1V），no output.
2. when IC alert, no matter reset is high or low, SD keep low;
3. customer changed 5 ICs, all appears SD alert after different working time;
4. their load is soundwave motor,  the voltage of motor is -25V~+25V. sine wave.
5. drive signal is 3~100Hz, is that OK for this part?

   thank you!

Yuan

Hi Yuan,

1. VREG/ VI_CM/ C_start voltages are normal.

2. Once Reset# is pulled low, SD will be forced to high. Refer to bottom of page 17 on d/s. If SD# pin is always low, please check if the device is good unit and the soldering.

3. So the device can work normally for some time, right? Under what working condition did the device fall into fault status? Is it delivering high power? 

4. This device is an audio amp that may have some limitations to support frequency as low as 3Hz. At least it won't work with current  How about the loading condition?

Regards,

Sam

Hi Sam,

thanks for your support.

the load is maximum 357W.

and here is the schematics:

Power amplifier board V0.1.pdf

Hi,

The schematic looked good.

1. First of all, please make sure that when RESET# pulled low, SD# was in high level. If it is not, please check the soldering. 

2. You may also refer to Table 1 in datasheet to check what kind of fault it's reporting.

3. What's the load resistance? The device has current limit as 15A, and can support ~350W on at least 3R loading. With lower loading resistance, it may trigger over current fault.

Regards,

Sam

Hi Sam,

7R loading.

when IC works, assert reset low, SD high. but when SD alert, it keeps low whether reset is high or low.

why? does it mean that the IC is broken?

thank you!

Yuan

Hi Yuan,

I can't tell the IC is damaged, but according to the datasheet, asserting reset low should make SD released to high level, independent of faults being present.

BTW, if the loading is 7R, we can't get 375W output. The max output we can support without a voltage clipping, is 50^2/2/7=178W. With 10% THD+N, it can support about 200W.

Regards,

Sam