Rev 2 - W24

Owner: @Rayyan Mahmood @Yuchen Lin

Purpose: Revision number 2 for the localization board is a board inspired by revision 1 which was designed 4 years ago. But now being designed from the ground up, and with a new team of designers, we plan to make the best possible localization and positioning system, replacing our current OTS alternative.

Block Diagram of localization board comprised of the bare minimum requirements needed for this board to function as intended

Evaluation Boards:

https://soldered.com/product/gnss-gps-l86-m33-breakout-with-easyc/

https://www.top-electronics.com/en/evaluation-kit-for-gps-l86-module#gallery

Component Selection:

Component Needed	Component Selected	Price	Comments	Stock

Component Needed	Component Selected	Price	Comments	Stock
MCU (STM32F446RET6)	https://www.digikey.ca/en/products/detail/stmicroelectronics/STM32F446RET6/5175962	$15.56		✅
GNSS Receiver IC	Datasheet: https://www.mouser.ca/datasheet/2/1052/QWSC_S_A0007269014_1-2576162.pdf	$19.11	Overall best option in market with versatility and price Can potentially leave the external antenna components as empty place holders on the board and determine values later Operates at 3.3V L80 wouldn’t be a bad GNSS Receiver IC to consider	✅
9 DOF IMU		$13.38	Operates at 1.8V	✅
Bidirectional Level Shifter		$1.27	Required to allow 1.8V IMU and 3.3V GNSS reciever IC to commuincate	✅
LDO (Voltage Regulator)	Still need to find one	N/A	Needed for dropping 3.3V input to 1.8V	N/A
Female Antenna Connector	Still need to find one	N/A	My thoughts were to use an SMA connector since that’s what one of the eval boards I found used. But a bit more research should be done before selecting Female Antenna	N/A
Male Antenna	N/A	N/A	I was geared towards using something like a Taoglas TG.10.0113. But more research should be done before selecting Male Antenna	N/A

Notes:

Need to figure out how to implement External Active Antenna. Section of datasheet providing info is added below.

LDO Selection:

After consideration, NCV8114ASN180T1G is the best choice because it has a lower dropout voltage than others. Also, the EN voltage is lower since the lowest is 0.9V so we can directly use the voltage input for the enable voltage. Also, the input and voltage range is valid at a reasonable price.

ICs	Component selected	Price	Comment	Stock

ICs	Component selected	Price	Comment	Stock
MIC5219YM5-TR	https://www.digikey.ca/en/products/detail/microchip-technology/MIC5219YM5-TR/771751	$1.84	Input Voltage Range: 2.5V to 12V 1 output voltage Output Voltage Range: Unknown Dropout Voltage (Max): 0.6V @ 500mA Number of pins: 5 Similar QFP	✅
AP7331-18WG-7	https://www.digikey.ca/en/products/detail/diodes-incorporated/AP7331-18WG-7/2182601	$0.50	Input Voltage Range: 2V to 6V Output Voltage Range: 0.8V to 5.0V 1 output voltage Dropout Voltage (Max): 0.3V @ 300mA Number of pins: 5 Similar QFP	✅
TLV73325PDBVR	https://www.digikey.ca/en/products/detail/texas-instruments/TLV73325PDBVR/5022376	$0.54	Input Voltage Range: 1.4V to 5.5V Output Voltage Range: 1.0V to 3.3V 1 output voltage Dropout Voltage (Max): 0.29V @ 300mA Number of pins: 5 Similar QFP	✅
NCV8114ASN180T1G	https://www.digikey.ca/en/products/detail/onsemi/NCV8114ASN180T1G/7066765	$0.76	Input Voltage Range: 1.7V to 5.5V Output Voltage Range: -0.3V to 6V 1 output voltage Dropout Voltage (Max): 135mV @ 300mA Number of pins: 5 Similar QFP	✅
TPS78428QDBVRQ1	https://www.digikey.ca/en/products/detail/texas-instruments/TPS78428QDBVRQ1/13562990	$1.02	Input Voltage Range: 1.65V to 6.0V Output Voltage Range: 0.65 V to 5.0 V 1 output voltage Dropout Voltage (Max): 115mV@ 300mA Number of pins: 5 Similar QFP	✅