CDCE62002 - Power up sequence

Kawai

Guru 19785 points

Other Parts Discussed in Thread: CDCE62002

Hi Team,

Could you please let me ask you about the power up sequence of CDCE62002 ?

I found the datasheet mentions that all supply voltage should be supplied simultaneously.

Our customer uses separate power supply to the analog supply voltage and the other supply voltage.
(Analog supply voltage is applied from LDO and other supply voltage is from DC/DC converter.)

[Question]
What would be the restriction to satisfy Note(2) above in the absolute maximum ratings ?
Please give us your advice.

Thanks and Best Regards,
Kawai

over 11 years ago

0 Alan O over 11 years ago

TI__Mastermind 32575 points

Hi Kawai-san,

I believe the restriction from Note (2) is to satisfy the power-on reset (POR) sequence to initialize the device registers from EEPROM, startup the crystal oscillator, and start the VCO calibration sequence as described in Table 21.

If their supply sequencing does not comply with Note (2), then I suggest they reset the device by toggling the /PD pin (L->H) after the slower power supply rail is above 2.64 V (high-limit of POR trip point).

Regards,
Alan

0 Kawai over 11 years ago in reply to Alan O

Guru 19785 points

Hello Alan-san,

Thanks for your advice.
I will ask customer to toggle /PD pin after all supply rails are stabled to 3.3V.

If the /PD pin is not accessible, I believe the Register2 (Address 0x02) bit7 has the same function, except for EEPROM data loading function.
Is my recognition correct ?

Best Regards,
Kawai

0 Alan O over 11 years ago in reply to Kawai

TI__Mastermind 32575 points

Your understanding is correct.

0 Kawai over 11 years ago in reply to Alan O

Guru 19785 points

Hi Alan-san,

Thanks for your help.

Best Regards,
Kawai

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CDCE62002 - Power up sequence