TIDUFA8
November 2024
1
Description
Resources
Features
Applications
6
1
System Description
1.1
Terminology
1.2
Key System Specifications
2
System Overview
2.1
Block Diagram
2.2
Highlighted Products
2.2.1
IWRL6432
2.3
Design Considerations
2.3.1
Reference Design Features
2.4
IWRL6432 Reference Design Architecture
2.4.1
IWRL6432: BOM Optimized Design
2.4.1.1
Device Power Topology
2.4.2
Power Distribution Network
2.4.3
Internal LDOs
2.4.3.1
Enabling and Disabling Low Power Mode
2.4.3.2
1.4V Power Supplies: APLL and Synthesizer
2.4.3.2.1
APLL 1.4V
2.4.3.2.2
SYNTHESIZER 1.4V
2.4.3.3
1.2V Power Supplies
2.4.3.3.1
RF 1.2V Supply
2.4.3.4
RF 1.0V Power Supply
2.4.4
Component Selection
2.4.4.1
1.8V DC-DC Regulator
2.4.4.1.1
Need for Forced PWM Mode Switching
2.4.4.1.2
Importance of Spread Spectrum Clocking
2.4.4.2
3.3V Low Dropout Regulator
2.4.4.3
FLASH Memory
2.4.4.4
Crystal
3
System Design Theory
3.1
Antenna Specification
3.1.1
Antenna Requirements
3.1.2
Antenna Orientation
3.1.3
Bandwidth and Return Loss
3.1.4
Antenna Gain Plots
3.2
Antenna Array
3.2.1
2D Antenna Array With 3D Detection Capability
3.2.2
1D Antenna Array With 2D Detection Capability
3.3
PCB
3.3.1
Via-in-Pad Elimination
3.3.2
Micro-Via Process Elimination
3.4
Configuration Parameters
3.4.1
Antenna Geometry
3.4.2
Range and Phase Compensation
3.4.3
Chirp Configuration
3.5
Schematic and Layout Design Conditions
3.5.1
Internal LDO Output Decoupling Capacitor and Layout Conditions for BOM Optimized Topology
3.5.1.1
Single-Capacitor Rail
3.5.1.1.1
1.2V Digital LDO
3.5.1.2
Two-Capacitor Rail
3.5.1.2.1
1.2V RF LDO
3.5.1.3
1.2V SRAM LDO
3.5.1.4
1.0V RF LDO
3.5.2
Best and non-Best Layout Practices
3.5.2.1
Decoupling Capacitor Placement
3.5.2.2
Ground Return Path
3.5.2.3
Trace Width of High Current Carrying Traces
3.5.2.4
Ground Plane Split
4
Link Budget
5
Hardware, Software, Testing Requirements and Test Results
5.1
Hardware Requirements
5.1.1
Connection to the USB to UART Bridges
5.1.2
USB Cable to Connect to Host PC
5.1.3
The Rx-Tx Attribution of RS232
5.2
Software Requirements
5.3
Test Scenarios
5.4
Test Results
5.4.1
Human Detection at 15 Meters in Boresight
5.4.2
Antenna Radiation Plots
5.4.3
Angle Estimation Accuracy in Azimuth Plane
5.4.4
Angle Resolution
6
Design and Documentation Support
6.1
Design Files
6.1.1
Schematics
6.1.2
BOM
6.1.3
PCB Layout Recommendations
6.1.3.1
Layout Prints
6.2
Tools and Software
6.3
Documentation Support
6.4
Support Resources
6.5
Trademarks
7
About the Authors
Features
Low-power, low-cost, 57GHz to 64GHz mmWave sensor using the IWRL6432
Design dimensions: 16mm x 33mm.
Single 5V supply with on board power distribution network.
Communication interfaces: UART, SPI, I2C (2-GPIOs and optional debug interface JTAG)
Antenna features:
Single element patch antenna.
120° field of view
Angular resolution of 19° in azimuth plane and 58° (for 2D antenna variant only) in elevation plane
Person detection up to 15 meters
FR4 based 4-layer PCB stack up using only through hole vias for cost optimization.
Simple, easy to integrate, one page schematic.