IWRL6432AOP Reference Design

Table of Contents

Introduction

This reference design showcases BOM (Bill of Materials) optimizations and a small form factor antenna. The 1.2V supply rail is derived internally, saving cost at the system level. It’s also possible to modify the design to a single rail 1.8V I/O design, further reducing system cost. Reference designs use the Antenna on Package(AOP) IWRL6432AOP mmWave sensor device.

Design Azimuth FOV (deg) Elevation FOV (deg) Azimuth Angular Resolution(deg) Elevation Angular Resolution (deg) Max Distance for Person (m) Board Dimensions (mm) Interface Type
IWRL6432AOP +/-70 +/-70 28 58 15 7 x 37 UART, SPI, GPIO

A comparison table of all reference designs can be found on the reference designs overview page.

📝 NOTE: Design Files
Design files (Assembly, Gerbers, CAD, PCB) are available with Radar Toolbox download. Files related to this reference design can be found at <RADAR_TOOLBOX_INSTALL_DIR>/hardware_docs/reference_designs/IWRL6432AOP/

IWRL6432AOP Reference Design

Antenna Picture & Dimensions

PCB Stackup

Please refer to below PCB stackup details for IWRL6432AOP Reference Design.

A detailed layout of this reference design with stackup is available in the Radar Toolbox.

Simulated Radiation Patterns

Simulated radiation patterns of IWRL6432AOP Reference Design for Azimuth and Elevation can be seen below.

Normalized Loopback Gain

In the pictures above, the X axis represents the angle (in degrees) and Y axis represents the gain (in dB).

Connection Details

Pin Descriptions

See pin descriptions for the reference design connector below. Please refer to the schematic for more information.

Pin Function Pin Function
1 5V IN 2 SPI_MISO
3 RS232_TX 4 GPIO_2
5 SPI_CS 6 SOP0
7 SPI_CLK 8 SPI_MOSI
9 RS232_RX 10 nRST
11 GND 12 GPIO_5

Interfacing with PC

The reference design uses a 1mm pitch 12-pin connector. In order to make the connection of the reference design and the USB to UART bridge easier, a DR100D254P12 pitch converter can be used. It has 1mm pitch female connector on one side where the reference design connector can mate and 2.54mm pitch male connector on the other side where connection to the USB to UART bridge can be placed.

A USB to UART bridge is required for connecting the AOP reference design with a PC. An example connection diagram is shown below.

*The UART bridge shown here is FT232RL USB to TTL 3.3V, 5V serial adapter

MSP-EXP432E401Y can be used as an alternate USB to UART bridge. It has XDS110 connectivity.

📝 NOTE: Operational Modes
The figure above shows the required connections for device operation in Functional Mode. To set the device in Flashing mode, SOP0 must be pulled to GND at power on.

📝 NOTE: Visualizer
On the PC side, the Industrial Visualizer should be used to connect with the device. This is because the SDK Visualizer, through SDK version 5.4, has a dependency on the XDS110 which is not present in this reference design.

Running the Out-of-Box Demo

  1. Connect the EVM to the PC via USB.
  2. Open the mmWave Visualizer inside mmWave-L-SDK tool and select the device. Check the SOP settings for Functional Mode.
  3. Navigate to Configuration Dashboard tab of the visualizer. Wait for AUTO detection of COM ports (else press refresh). Alternatively, manually select device COM port (if not already selected). Select preset configuration under Configuration Selection drop-down.
  4. Click on Send Config to Device.
  5. After configurations are successfully sent, the Plots tab displays range plot via radar point cloud information.

Schematic

Simple single page schematic is shown below. Note, schematic and additional design files are available with Radar Toolbox download.

Manufacturing Guidelines

The details on manufacturing this antenna can be found in the TI mmWave Radar Sensor RF PCB Design, Manufacturing and Validation Guide

Board Manufacturer

TTM Technologies - https://www.ttm.com/en

Material Details

Isola Group - https://www.isola-group.com/