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PSoC™ 5, 3 & 1 Forum Discussions

eeEn_4618901
Level 4
Level 4
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Hi, I want to modulate FSK with PSoC.I found 2 studies. 1)https://www.cypress.com/documentation/application-notes/an60594-psoc-3-and-psoc-5lp-low-frequency-fs... 2) https://www.cypress.com/documentation/application-notes/an76458-psoc-5lp-high-voltage-120-240-vac-po... Can I only use the FSK modulation block in  (2)  ? How much can I increase the frequency in these 2 studies?

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odissey1
Level 9
Level 9
First comment on KBA 1000 replies posted 750 replies posted

eeEn,

What carrier frequency you need?

The IDAC8 utilized in the FSK modulator component can be tweaked to produce somewhat decent sine output up to approx 1.5 MHz. The AN #1 states that 0.5 Mhz with IDAC8 is OK. Please note that PSoC5 Opamps have GBP cutoff at ~1 MHz, so you probably have to use external opamps.

/odissey1

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Dear Bota, Frequency :300Mhz or 433MHz Need to make an output circuit? Best regards

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No, no! PSoC5 max bus frequency is only 80MHz, you need external modem to handle 300MHz.

/odissey1

eeEn,

For FSK with carriers in the 300 to 433 MHz range, there are dedicated ICs designed to handle this frequency range.  They are designed to handle higher internal frequencies.

It sounds like you're trying to support frequencies often used by automotive for the Key FOB and TPM sensors.

The PSoC5's modulation capabilities are limited by the maximum frequency supported by the silicon geometries.

Len

Len
"Engineering is an Art. The Art of Compromise."
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