Regarding CYUSB3314 crystal circuit.

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

cross mob
YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Hello

Below figure is CYUSB3314 crystal circuit.

There is only external caps in CYUSB3314 crystal circuit.

Is it unnecessary for external components other than caps?

pastedImage_6.png

Does CYUSB3314 internally have below resisters(Rf and Rd) for crystal circuit?

pastedImage_8.png

Best Regards.

Yutaka Matsubara

0 Likes
1 Solution
HirotakaT_91
Moderator
Moderator
Moderator
500 replies posted 250 replies posted 100 replies posted

AN91378 described "Do not connect any series resistor to the XTL_OUT and XTL_IN pins of the crystal. Placing a series resistor will add resistance to the crystal ESR, resulting in increased crystal power dissipation and startup time."

So, It is unnecessary for external components other than caps.

You can also refer to FX3. It is also unnecessary to connect external resistor.

Thanks,

Hirotaka Takayama

View solution in original post

0 Likes
3 Replies
HirotakaT_91
Moderator
Moderator
Moderator
500 replies posted 250 replies posted 100 replies posted

AN91378 described "Do not connect any series resistor to the XTL_OUT and XTL_IN pins of the crystal. Placing a series resistor will add resistance to the crystal ESR, resulting in increased crystal power dissipation and startup time."

So, It is unnecessary for external components other than caps.

You can also refer to FX3. It is also unnecessary to connect external resistor.

Thanks,

Hirotaka Takayama

0 Likes
YuMa_1534086
Level 7
Level 7
Distributor - Macnica (Japan)
500 replies posted 250 sign-ins 10 likes received

Hello

I think that crystal circuit requires Rf and Rd.

Does CYUSB3314 internally have two resisters(Rf and Rd) for crystal circuit?

Best Regards.

Yutaka Matsubara

0 Likes

I checked the internal materials.

CYUSB3314 internally have resisters for crystal circuit.

Regards,

Hirotaka Takayama

0 Likes