ADRV9002
Recommended for New Designs
The ADRV9002 is a highly integrated RF transceiver that has dual-channel transmitters, dual-channel receivers, integrated synthesizers, and digital signal...
Datasheet
ADRV9002 on Analog.com
ADRF5717
Recommended for New Designs
The ADRF5717 is a silicon, 2-bit digital attenuator with 48 dB
attenuation range in 16 dB steps supporting glitch-free operation.
The ADRF5717 operates...
Datasheet
ADRF5717 on Analog.com
Hi,
I have questions about External LNA Gain Control with the following hardware setup:
- ADRV9002 on BytePipe x9002 module (Zynq UltraScale+ host)
- ADRF5717 variable attenuator in front of RX1 (channel 1 only)
- Attenuator control: 3-bit parallel, LE tied to VDD, D5 -> AGPIO_8, D6 -> AGPIO_9. Accessible states: 0 / 16 / 32 / 48 dB
- TES version 0.29.0
I have read UG-1828 (p.180) states that "N + M + L should not exceed 29 dB" per LNA.
A previous EZ thread answered confirms that the AGC actually supports up to 87 dB of external attenuation via the same 2 AGPIO pins, and that the user guide is in the process of being updated:
(https://ez.analog.com/rf/wide-band-rf-transceivers/design-support-adrv9001-adrv9007/f/q-a/579723/external-lna-with-agc)
There is also the EZ article "Implement an External LNA in TES":
(https://ez.analog.com/rf/wide-band-rf-transceivers/tes-gui-software-support-adrv9001-adrv9007/w/documents/32216/implement-an-external-lna-in-tes)
The ADRF5717 has physical 16 dB steps:
N = 16, M = 16, L = 16 -> 48 dB total external attenuation
Given the 87 dB limit confirmed in the previous thread, 48 dB should fit comfortably. Still, I have some open questions:
1. Based on the 87 dB total external attenuation feature mentioned in the previous thread, is it possible to configure a single external attenuator (one physical chip, 4 states, 2 AGPIO control bits) with N=M=L=16 dB summing to 48 dB total? Or does the 87 dB feature require multiple external LNA devices in cascade?
2. TES gain table generation issue (TES 0.29.0):
When I enable External LNA in the RX configuration of TES with numberLnaGainSteps = 3 and lnaGainSteps_mdB = [16000, 16000, 16000] and try to export the RX gain table, TES does not produce the table.The internal-only gain table exports normally. No clear error message is shown. Could that be the reason the gain table is not generated?
Thanks in advance,
Leo
