IWRL6432 FCCSP Reference Design
Table of Contents
Introduction
This reference design showcases BOM 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, thus further reducing system cost. Reference designs use single patch per antenna which are rotated by 60 deg. This rotation provides an optimum tradeoff between antenna coupling and azimuth FOV.
| 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 |
|---|---|---|---|---|---|---|---|
| IWRL6432 FCCSP 1D | +/-60 | +/-60 | 19 | N/A | 15 | 16 x 33 | UART, SPI, GPIO |
| IWRL6432 FCCSP 2D | +/-60 | +/-60 | 19 | 58 | 15 | 16 x 33 | 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>/docs/reference_designs/IWRL6432_FCCSP_Reference_Design/design_files
1D Antenna Variant
All TX and RX antenna patches are in line. Max antenna width is 3.5mm.
Antenna Picture & Dimensions
PCB Stackup
Please refer to below PCB stackup details for IWRL6432 FCCSP Reference Design (1D Antenna).
Detailed layout of this reference design with stackup are available with Radar Toolbox download.
Simulated Radiation Patterns
Simulated radiation patterns of IWRL6432 FCCSP Reference Design (1D Antenna) for Azimuth and Elevation can be seen below.
RX Antenna
In the above pictures X axis represents the angle (in degrees) and Y axis represents the gain (in dB).
TX Antenna
In the above pictures X axis represents the angle (in degrees) and Y axis represents the gain (in dB).
2D Antenna Variant
TX2 is offset from TX1.
Antenna Picture & Dimensions
PCB Stackup
Please refer to below PCB stackup details for IWRL6432 FCCSP Reference Design (2D Antenna).
Detailed layout of this reference design with stackup are available with Radar Toolbox download.
Simulated Radiation Patterns
Simulated radiation patterns of IWRL6432 FCCSP Reference Design (2D Antenna) for Azimuth and Elevation can be seen below.
RX Antenna
In the above pictures X axis represents the angle (in degrees) and Y axis represents the gain (in dB).
TX Antenna
In the above pictures 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
A USB to UART bridge is required for connecting the FCCSP 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
📝 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 5.3, has a dependency on the XDS110 which is not present in this reference design.
Running the Out-of-Box Demo
This reference design’s BOM specifies a flash part which differs from that which is used on the IWRL6432BOOST EVM. Because of this, an alternate flashable binary file should be used to run the out-of-box demo. The following appimage, which bypasses the flash device ID check, may be used for this purpose:
- {RADAR_TOOLBOX_INSTALL_DIR}\source\ti\examples\Presence_and_Motion_Detection\prebuilt_binaries\motion_and_presence_detection_demo_flashCheckBypass.Release.appimage
It is also important to note that the antenna patterns on both variants of the reference design do not match the antenna pattern of the IWRL6432BOOST EVM. This means that the anteena geometry configuration settings must be updated for the AoA processing to happen correctly. Existing configurations can be modified to specify the correct antenna geometry using the commands listed below. Alternatively, .cfg files for both antenna variants of this reference design are provided at {RADAR_TOOLBOX_INSTALL_DIR}\docs\reference_designs\IWRL6432_FCCSP_Reference_Design\chirp_configs
| Antenna Variant | CLI Command |
|---|---|
| 1D | antGeometryCfg 0 0 0 1 0 2 0 3 0 4 0 5 2.418 2.418 |
| 2D | antGeometryCfg 1 0 1 1 1 2 0 3 0 4 0 5 2.418 2.418 |
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/