CDCM6208 / about power up and configuration

Toshiyuki

Other Parts Discussed in Thread: CDCM6208, CDCM6208V1

Hi,

Customer will control CDCM6208 by using I2C mode.In normal operation, could we use SYSNCN bit to able the outputs during SYNCN pin is low? Is the bit overwritten?

They are considering pins setting as below.

・RESETN pin = open (High)

・SYNCN pin = pull down it to ground to disable the outputs

・PDN pin = open (High)

After setting initial condition with I2C, we will write SYNC bit high to able the outputs.

Best Regards,

Kato

over 10 years ago

0 Arvind Sridhar over 10 years ago

TI__Mastermind 24205 points

Hi Kato-San,

The SYNC pin overrides the register setting.

Regards

Arvind Sridhar

0 Toshiyuki over 10 years ago in reply to Arvind Sridhar

Mastermind 7075 points

Hi Arvind - san,

Thank you for the reply. Would you give us some more details? Could we set output enable by using SYNCN bit register while SYNCN pin is low?

Customer has to fix RESETN, SYSNCN and PDN pins because their CPU don't have enough signal.

Best Regards,

Kato

0 Arvind Sridhar over 10 years ago in reply to Toshiyuki

TI__Mastermind 24205 points

Hi Kato-San,

SYNCN pin held low disables all the outputs regardless of what the polarity of the SYNCN register bit.

Regards

Arvind Sridhar

0 Toshiyuki over 10 years ago in reply to Arvind Sridhar

Mastermind 7075 points

Hi Arvind -san,

If customer set as below, what frequency will be output before they program with I2C?

・input frequency : 19.2MHz

・RESETN pin = open (High)

・SYNCN pin = open (High)

・PDN pin = open (High)

Best Regards,

Kato

0 Arvind Sridhar over 10 years ago in reply to Toshiyuki

TI__Mastermind 24205 points

Hi Kato-San,

The I2C default state for CDCM6208V1 is shown below. The selected reference is a 25 MHz Crystal with the VCO and output frequencies as shown in the figure below.

Regards

Arvind Sridhar

0 Toshiyuki over 10 years ago in reply to Arvind Sridhar

Mastermind 7075 points

Hi Arvind -san,

Customer is planning to input 19.2MHz. In this case, what frequency will be output?

In addition, If they stop input frequency, are all output ports high or low fixed?

Best Regards,

Kato

0 Toshiyuki over 10 years ago in reply to Toshiyuki

Mastermind 7075 points

Hi Arvind -san,

Customer's configuration is shown below.

・PRI_REFP -> 19.2MHz/CMOS2.5V

・PRI_REFN,SEC_REFP,SEC_REFN　pins = open

・VDD_SEC_REF = GND (Register 4 Bit 5 = 0),

・RESETN pin = open (High)

・SYNCN pin = open (High)

・PDN pin = open (High)

・REF_SEL pin = open (High)

In this case, I understand all outputs is mute because Secondary input is selected. Is my understanding correct?

Regards,

Kato

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CDCM6208 / about power up and configuration