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This version (11 Oct 2021 15:45) was approved by Zuedmar Arceo.The Previously approved version (11 Oct 2021 02:21) is available.Diff

EVAL-CN0521-EBZ User Guide

Overview

CN0521 is a small USB-powered RF Low Noise Amplifier that is optimized for 2400 MHz operation. The amplifier typically provides 22 dB of gain through its RF band of operation, boosting signals for various communication protocols such as ISM, MC-GSM, W-CDMA, TD-SCDMA, and LTE . It provides a circuit that includes a high-speed overpower cutoff that protects sensitive downstream equipment connected to the receiver system and automatically turns back on when the RF power level gets back within the acceptable range. It requires a 3.3 V Micro USB supply for normal operation. The input and output, both populated with edge-mounted SMA connectors, are DC blocked and matched to 50 Ω for ease of use. More information on this board can be found at PlutoSDR Amplifier.

 Figure 1. EVAL-CN0521-EBZ Board

The heart of this Circuit Note features ADL5523 which is a high-performance GaAs pHEMT low noise amplifier. It provides a high gain and low noise figure for single down-conversion IF sampling receiver architectures as well as direct down-conversion receivers. It is easy to tune, requiring only a few external components. The device can support operation voltages from 3 V to 5 V, and the current draw can be adjusted with external bias resistors for applications requiring very low power consumption.

The ADL5904 is a dual-function radio frequency (RF) TruPwr detector that operates from DC to 6GHz. It provides RMS power measurement along with a programmable envelope threshold detection function. The RMS power measurement function has a 45 dB detection range, nominally from −30 dBm to +15 dBm. The RMS power measurement function features low power consumption and an intrinsically ripple-free error transfer function.

The EVAL-CN0521-EBZ board connects through SMA and is powered by the bus voltage from the USB port.
 Figure 2. EVAL-CN0521-EBZ Simplified Block Diagram

General Setup

 Figure 3. EVAL-CN0521-EBZ General Setup

LED, DS1 from CN0521, will automatically turn on indicating that the CN0521 is powered and operational. If the LED is off, the CN0521 could still be powered properly, but the RF input power into the amplifier might be activating the automatic shutdown, so try to lower the RF input signal by 10dB and see if the LED turns on.

Connectors

 Figure 4. EVAL-CN0521-EBZ Connectors

SMA Connectors

The SMA connectors are used for the RF Input and output connections.

  • J1 is the RF Input SMA Male Connector that would be connected to an antenna.
  • J2 is the RF Output SMA Female Connector that would be connected to a radio or piece of RF Equipment.

Power Connector

  • P1 is the Micro USB port used to provide 3.3 V power to the board.

Getting Started

Required Equipment

  • Two (2) Micro USB Power Adaptor or Micro USB to USB Cable for powering ADALM-PLUTO and EVAL-CN0521-EBZ
  • One (1) SMA Male to SMA Male Cable
  • One (1) SMA 10 dB RF Attenuator

ADALM-Pluto Preparation

Firmware Loading

  1. Unzip the downloaded file.
  2. Connect Pluto to host PC or laptop using a Micro USB cable in the terminal with a USB symbol.
  3. Open the Pluto mass storage device.
  4. Open the unzipped firmware file.
  5. Copy the file, pluto.frm, to the Pluto mass storage device. Figure 5. Copying Pluto Firmware to the Pluto Mass Storage Device
  6. This will cause LED1 to blink rapidly. This means programming is taking place. Do not remove power (or USB) while the device is blinking rapidly. It does take approximately 4 minutes to properly program the device.
  7. Once the device is done programming, it will re-appear as a mass storage device.
  8. Eject (don't unplug) the Pluto mass storage device. Figure 6. Ejection of Pluto Mass Storage Device
  9. Now the USB cable can now safely disconnect from the PC.

Updating to the AD9364

  1. Connect again the Pluto to host PC using a micro USB cable.
  2. Open any serial terminal application (ex. TeraTerm, Putty) and SSH to 192.168.2.1, the username is root and password is analog. Figure 7. Serial Terminal Configuration
  3. To change parameters to the AD9364 configuration, enter the following commands, line by line:
    # fw_setenv attr_name compatible
    # fw_setenv attr_val ad9364
    # reboot

    Figure 8. AD9364 Configuration

  4. Eject (don't unplug) the Pluto mass storage device.
  5. Now the USB cable can now safely disconnect from the PC.
  6. Connect again Pluto to PC using Micro USB cable and proceed setting up the hardware test setup following the instruction in the next section.

Test Setup

Normal Operation

Figure 9. EVAL-CN0521-EBZ Test Setup

  1. Connect the RF TX of Pluto SDR to J2 of the EVAL-CN0521-EBZ Board
  2. Connect J1 of the EVAL-CN0521-EBZ Board to an RF attenuator to protect the RX of Pluto from exceeding its limits.
  3. Connect P1 (micro USB) connector of the EVAL-CN0521-EBZ Board into a PC USB port or 5V USB charger.
  4. The DS1 LED of CN0521 will automatically turn on indicating the board is powered on and is in operation.
The ADALM-Pluto can be configured using an IIO Oscilloscope, visit the website on IIO Oscilloscope to know more about the tool.

IIO Oscilloscope

Make sure to download/update to the latest version of IIO Oscilloscope found on this linkhttps://github.com/analogdevicesinc/iio-oscilloscope/releases
  1. Once done with the installation or an update of the latest IIO Oscilloscope, open the application. The user needs to supply a URI which will be used in the context creation of the IIO Oscilloscope and the instructions can be seen from the previous section.
  2. Press refresh to display available IIO Devices, once ADALM-Pluto appeared, press connect.

Figure 9. IIO Oscilloscope Configuration

ADALM Pluto Output

The plot shown below is the ADALM Pluto output with the RF TX and RX connected directly producing a -16 dBFS RF power reading:

The plot shown below is the ADALM Pluto output with the RF attenuator connected only producing a -26 dBFS RF power reading:

Normal Operation

To configure the EVAL-CN0521-EBZ with the RF switch CLOSED, replicate configuration on the IIO Oscilloscope Tab as shown below:

The plot is as shown below with -14 dBFS RF power reading:

Auto Shutdown Operation

To configure the EVAL-CN0521-EBZ with the RF switch OPENED, replicate configuration on the IIO Oscilloscope Tab as shown below:

The plot is as shown below with -23 dBFS RF power reading:


WARNING

Connecting the EVAL-CN0521-EBZ Board directly to the input (Rx) of a radio or other piece of RF equipment may exceed the absolute maximum ratings for the RF Input. (which is +2.5 dBm for the ADALM-PLUTO). Doing this may permanently damage the input. Never do this in normal operation.

Schematic, PCB Layout, Bill of Materials

EVAL-CN0521-EBZ Design & Integration Files

  • Schematics
  • PCB Layout
  • Bill of Materials
  • Gerber Files
  • Allegro Board File

End of Document

resources/eval/user-guides/circuits-from-the-lab/cn0521.txt · Last modified: 11 Oct 2021 15:45 by Zuedmar Arceo