TMS320C6674 Designation

user5177935

Other Parts Discussed in Thread: TMS320C6678, MSP430FR6989, TMDSEVM6678, TMS320C6674, TPS54620

Hello.I designed a board,based on the TMS320C6678 EVM board. Now I want to connect it to my PC,but it failed(CCS5.5).

I tested the voltage and found the VCC1V8_AUX turned out 2.1V,how is that coming?

(I used a MSP430FR6989 to control the power-supply sequence , just after I downloaded the program into the MSP430 ,the VCC1V8_AUX changed to 2.1V)

over 6 years ago

0 Yordan Kovachev over 6 years ago

TI__Guru**** 161600 points

Hi,

I tested the voltage and found the VCC1V8_AUX turned out 2.1V,how is that coming?

Can you share the relevant part of the schematic?

Best Regards,
Yordan

0 user5177935 over 6 years ago in reply to Yordan Kovachev

Prodigy 100 points

file.zip

0 Yordan Kovachev over 5 years ago in reply to user5177935

TI__Guru**** 161600 points

Hi,

Are you using 1% resistors in this circuit?

Also can you elaborate on the following:

(I used a MSP430FR6989 to control the power-supply sequence , just after I downloaded the program into the MSP430 ,the VCC1V8_AUX changed to 2.1V)

Isn't your MSP preprogrammed to turn on/off the power supplies? What program are you downloading into it?

Best Regards,
Yordan

0 user5177935 over 5 years ago in reply to Yordan Kovachev

Prodigy 100 points

To control the power-supply sequencing , control cdce6200 to generate the clock signal , reset , turn on/off the 6674 GPIO.

0 user5177935 over 5 years ago in reply to Yordan Kovachev

Prodigy 100 points

Is there any configuration in the 6674 will change the voltage of VCC1V8_AUX?I took off the TXS0108EPWR which is connected with 6674(in the file I sent to you) and found the VCC1V8_AUX returned to normol(1.8V).

0 Yordan Kovachev over 5 years ago in reply to user5177935

TI__Guru**** 161600 points

Hi,

No there shouldn't be a configuration that changes the VCC1V8_AUX...

I took off the TXS0108EPWR which is connected with 6674(in the file I sent to you) and found the VCC1V8_AUX returned to normol(1.8V).

I am not sure what your power supply circuit looks like by this one file you provided. It is connected correctly, as I said the only problem there could be if you use resistors with tolerance different than 1% (which is quite unlikely).

The TI_TXS0108EPWR is a level shifter used to match the signal levels on the JTAG (TCLK, TDI, TDO, TMS, TRST, EMUo & EMU1) and the TSIP0_RX0/1/2/3, TSIP0_TX0/1/2/3, TSIP1_RX0/1/2/3 & TSIP1_TX0/1/2/3...

Let me check what is happening on my TMDSEVM6678, which is the reference board for your device TMS320C6674..

Best Regards,
Yordan

0 Yordan Kovachev over 5 years ago in reply to Yordan Kovachev

TI__Guru**** 161600 points

Okay, I measured TP22 on the TMDSEVM6678:

As you can see this source VCC1V8_AUX is derived, using the TPS73701 ldo, from the VCC3V3_AUX:

As you can see VCC3V3_AUX is coming directly from the 12V DC output, and is being formed by the TPS54620 step-down dc-dc converter, no processor settings here (neither from the TMS320C667x device, nor from the MSP430).

I measured both VCC1V8_AUX & VCC3V3_AUX and they are both as expected:

VCC1V8_AUX: