I will post for the first time.
I would like to know about the power supply sequence of TMS320C6742.
A power supply sequence circuit was constructed based on the circuit described in the document "TMS320C6742 Power Consunption".
I changed TPS62353YZG to TLV62568ADRLT because I don't want to use BGA of small device on the board. (Peripheral circuit also changed)
I thought it was sequenced by EN, but it was not sequenced according to the waveform shown in "TMS320C6742 Power Consunption".
When observed with an oscilloscope, when the 1.2V_core (TLV62568ADRLT) output rises to about 0.8V, the 1.2V_static (TPS62232DRY) output is 1.2V. (Sequence control by EN is effective)
However, the output voltage of 1.8V_static(TPS62231DRY) and 3.3V_static(Si2333DDS) was not sequenced.
According to the voltage rise of 1.2V_core, the output voltage rises up to about 1.4V.
After that, when the output of 1.2V_static becomes 1.2V, the output of 1.8V_static rises to 1.8V. (Control is not working)
Before the output of 1.2V_core rises, the output voltage of 3.3V_static starts to rise and becomes about 2V.
When the output of 1.2V_core begins to rise, the output voltage of 3.3V_static will fall once and become about 1.6V.
When 1.8V_static becomes 1.4V, the output voltage of 3.3V_static becomes 3.3V.
The voltage is controlled in the order of 3.3V_static→1.2V_static→1.8V_static→1.2V_core.
This period is about 1.2 msec.
The reset is applied to the DSP for 400 usec after all the power supplies have reached the desired values.
Waveform file cannot be uploaded due to security restrictions.
I just changed the converter for 1.2V_core based on the circuit shown in TMS320C6742 Power Consunption. Is there any reason that sequence control is not performed?
It is recommended to provide sequence control at power-on, but what is the purpose of providing a circuit?
Is there a problem with the DSP due to lack of sequence control?
All power supplies are reset until they reach the desired values. Is there a problem outside DSP that cannot be prevented only by resetting the DSP?
If there were no resets, would there be a problem?
Please note that the text may be strange because I am using a translation software.