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AD9237-40 power consumption

Terumasa
on Sep 8, 2014

Hello

We check power consumption of AD9237-40 both power scaling enable and disable .
Datasheet figure 43 and 44 describle only power consumption by 10MSPS at power scaling disable and enable.
Please let me knoe about power consumption when we use  AD9237-40 at 6MSPS.


Question 1
We think that power consumption of AD9237-40 (6MSPS) is about 90mW from figure 43.
Is it correct ?


Question 2
In Figure 44,slope of power consumption is varied by product name (samplng rate)

If we use AD9237-40 at 6MSPS, should we look not slope of AD9237-40 but slope of AD9237-20 at figure 44?

Could you give me advice about power consumption when we use below condtion ?

If we use slope of AD9237-40, we think that  power consumption is about 50~60mW from figure 44.
If we use slope of AD9237-20, we think that  powe consumption is about 65~70mW from figure 44.
Is is correct ?

Operated Condition
Power supply: 3V
MODE2 pin = 2/3 AVDD (Span factor:1, Power scaling: enabled) or MODE2 pin =AVDD (Span factor:1, Power scaling: disbled)
6MSPS

If there is any question, please let me know it.

Regards,

Terumasa

  • 0
    •  Analog Employees 
    on Nov 10, 2014 8:52 PM

    Thank you for your inquiry. Someone from 's team will assist you.

  • 0
    •  Analog Employees 
    on Nov 11, 2014 3:45 AM

    Dear Terumasa-san,

    I apologize for the late reply. There is a problem with our message delivery system.

    Because I do not have an evaluation setup ready to try on the bench, I can only give you an estimate based on information in the datasheet.

    QUESTION 1: Power of AD9237-40 (6MSPS)?
    For analog power:
    Figure 43 is for analog power even though the caption says “Total Power”. I used datasheet Figure 43 for AD9237-40 and backwards extrapolated down to 6MSPS. This gives an analog power value of about 95mW at 6MSPS

    For driver power:
    I used the IDRVDD value from the AD9237-65 and AD9237-20 to create a linear IDRVDD vs. Sample Rate relationship. I believe this will give a higher current (pessimistic) at 6MSPS than real, because the true IDRVDD vs. Sample Rate is not linear. Anyway, this yields an estimated value of IDRVDD = 2.2mA at 6MSPS, which means the power due to DRVDD = 2.2mA x 2.5V = 5.5mW at 6MSPS.

    So, the estimated typical AD9237-40 total power with Power Scaling off, at 6MSPS is 95mW + 5.5mW = 100.5mW. This is with sine wave input and nominal supply voltages.

    QUESTION2: Power of AD9237-40 (6MSPS) with Power Scaling. Which Power Slope to Use?
    For analog power:
    Below 20Msps, we must use the slope for AD9237-20. So, at 6Msps I agree with you that the power will be just below 70mW (let’s say 69mW). Again this is analog power.

    For driver power:
    The driver power is not affected by Power Scaling mode, so at 6Msps the driver power will still be about 5.5mW.

    So, the estimated typical AD9237-40 total power with Power Scaling on, at 6MSPS is 69mW + 5.5mW = 74.5mW. This is with sine wave input and nominal supply voltages.

    Again, I'm sorry for the late reply.

    Please take care,

    Doug