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ADRV9008-1 digital gain & AGC

Category: Hardware
Product Number: ADRV9008-1

We are trying to configure the AGC with an ADRV9008-1.

We have a custom gain table that uses 3dB on the gain compensation block.

According to Figure 75 on UG-1295 the gain compensation is done after the APD, HB1 and HB2 power measurements.

So if we want to get -12dBFS on the IQ data, do we have to configure the AGC for: -12dBFs - digital gain (-15dBFs for a digital gain of 3)?

Are there any additional gain/losses in the other blocks that need to be accounted for (i.e. RFIR, DC CORR, DDCHB) to set the target dBFs level on the AGC?

Top Replies

  • According to Figure 75 on UG-1295 the gain compensation is done after the APD, HB1 and HB2 power measurements.

    These are the measurement blocks that compare the programmed thresholds level with the actual value which was seen by the above components (like APD, HB1, & HB2) and apply the gain attack/recovery based on set values.

    So if we want to get -12dBFS on the IQ data, do we have to configure the AGC for: -12dBFs - digital gain (-15dBFs for a digital gain of 3)?

    Can you please more details about this, where do you want to get -12 dBFS IQ data, and is the 3 dB gain added before the APD block?

  • I am aware of the use of the use of APD, HB1 and HB2 as measurements blocks used by the AGC. My question is that since these measurement blocks are before the "digital gain block" (internal to the ADRV as indicated in the figure below and with a value specified on the gain table), will the AGC automatically compensate for the "digital gain" or do we have to enter an AGC threshold that accounts for the digital gain? 

    So, for example, lets assume that I have a gain table where all rows have the "Signed Digital Gain" set to +3dB. Then, If I want the IQ data I get through the JESD to be limited at ~-12dBFs. Do I set the AGC thresholds to -12dBFs (AGC will automatically compensate for the digital gain) or do I set the AGC thresholds to -15dBFs (manually compensate for the 3dB digital gain)?

    Also, will the other blocks (i.e. RFIR, DC CORR, DDCHB) need to be accounted when setting the threshold levels in the AGC?

  • No need to account the digital gain for the AGC threshold, ADRV AGC automatically compensates.

    Also, will the other blocks (i.e. RFIR, DC CORR, DDCHB) need to be accounted when setting the threshold levels in the AGC?

    Not required to account when setting the AGC threshold.