ADC12D1800 - RCLK+/- Duty Cycle Specification

Hiroshi Katsunaga

Mastermind 6480 points

Other Parts Discussed in Thread: ADC12D1800

Hello,

My customer has a question about ADC12D1800.

[Q] Could you tell me a specification of RCLK+/- Duty Cycle ?

They are going to use Auto Sync with External RCLKs.

They plan to make External RCLKs from LMK04808B.

Regards,

Hiroshi Katsunaga

over 13 years ago

0 Marjorie Plisch over 13 years ago

TI__Expert 3940 points

Hi Katsunaga-san,

Has the customer seen the Apps Note related to AutoSync? This discusses driving the RCLK externally. Nominally, the RCLK duty cycle should be 50%.

http://www.ti.com/general/docs/lit/getliterature.tsp?literatureNumber=snaa073f&fileType=pdf

Kind regards,

Marjorie

0 Hiroshi Katsunaga over 13 years ago in reply to Marjorie Plisch

Mastermind 6480 points

Hi Marjorie-san,

My customer has seen the Apps Note (SNAA073F).

Does the RCLK duty cycle require accuracy?

Do you have specification of min / max RCLK duty cycle?

Best Regards,

Hiroshi Katsunaga

0 Jim Brinkhurst1 over 13 years ago in reply to Hiroshi Katsunaga

TI__Mastermind 44680 points

Hi Katsunaga-san

As stated earlier we do not have an official specification for the RCLK input duty cycle requirement.

Since the customer is generating both CLK and RCLK for the ADC devices in the system, the RCLK will be created as a divided down version of CLK. I would presume that if RCLK is created by dividing the CLK frequency by 4 the duty cycle should be quite close to 50%.

I would recommend that they keep the RCLK duty cycle to 50% +/-1% or better. If they are generating the RCLK using the method I expect this should not be a problem.

I hope this is helpful.

Best regards,

Jim B

Data converters

Data converters forum

ADC12D1800 - RCLK+/- Duty Cycle Specification