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AIROC™ Bluetooth Forum Discussions

slowhandGarcia
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Hello Infineon Support Team,

I have used the CYW920719B2Q40EVB-01 eval board to write a simple BLE Beacon application that beacons out my unique UUID at a particular packet frequency.

Currently also working on a CYW20721B2KUMLG module similar to the carrier module on the CYW920719B2Q40EVB-01 Eval board
(shown below for reference).

slowhandGarcia_0-1671832028494.png

Need some things clarified before sending it out to a PCB Manufacturer:

1.  Looking at reference schematic for the CYW920719B2Q40EVB-01 Carrier Module, there is a Band Pass Filter in between Pin 18 (BT_RF) and the antenna/matching network:

slowhandGarcia_1-1671832052886.png

The BLE Beacon application is programmed to only transmit and not receive so I assume that this Band Pass Filter is not required for my design. Is this assumption correct? I see the following note in the design guidelines:

slowhandGarcia_2-1671832155208.png

This means filtering out harmonics from going into the CYW20719 chip or filtering out harmonics being transmitted by the
CYW20719?


2. Our CYW20721B2KUMLG module has 4 breakout pins for the BT UARTS. Would I be able to program my module using the
using the eval board? Looking at the BT/PROG UART LEVEL TRANSLATORS:

slowhandGarcia_3-1671832205906.png

Can I remove the jumpers on the J5 headers and connect my module directly to the 2,4,6,8 pins on that J10 connector
to program sw/fw on my module using ModusToolbox? Assuming I am powering on the CYW20721B2KUMLG module correctly this should work?

 

Thanks in advance,

Charly

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advait_kulkarni
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100 sign-ins 100 replies posted 25 solutions authored

Hi @slowhandGarcia ,

For the band pass filter, it always advised to follow the schematic provided, however, i am checking with the hardware team regarding this specific case and will get back to you as soon as possible.

You can program the module using eval board and PUART lines, although you might not be able to use AIROC HCI protocol. You can surely try and let us know if you are getting any errors.

You can also go for usb-uart converter and use it.

Thanks and regards,

Advait Kulkarni

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advait_kulkarni
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100 sign-ins 100 replies posted 25 solutions authored

Hi @slowhandGarcia ,

For the band pass filter, it always advised to follow the schematic provided, however, i am checking with the hardware team regarding this specific case and will get back to you as soon as possible.

You can program the module using eval board and PUART lines, although you might not be able to use AIROC HCI protocol. You can surely try and let us know if you are getting any errors.

You can also go for usb-uart converter and use it.

Thanks and regards,

Advait Kulkarni

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advait_kulkarni
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100 sign-ins 100 replies posted 25 solutions authored

Hi @slowhandGarcia ,

I have checked with our hardware team and it is necessary to use BPS for tx as well to block harmonic frequencies.

Thanks and regards,

Advait Kulkarni

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Hi Advait,

Thanks for the response.  I will add the Band Pass Filter to my design.  

Another question for the hardware team:

Is there any concerns with using voltage dividers off my main supply voltage (lets say its 3.6V) to achieve the  3.3 V and 1.8 V supplies required for my module? As apposed to using step-down DC/DC converters to achieve the 3.3V and 1.8V?

Thanks in advance,

Charly

 

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advait_kulkarni
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Hi @slowhandGarcia ,

In principle, a voltage divider circuit can be used for low volt signals like in your case. However, it is still an inferior choice compared to buck converters, and there could also be issues with stability of the desired output signal and efficiency in power delivery. Kindly monitor these things to avoid harm to your module.

Thanks and regards,

Advait Kulkarni.

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