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- device : CYUSB3064.
- IO voltag 3.3V
- PMODE[2:0]:0F1
- CX3 internal Pull-up 50KΩ. Internal Pull-down 10KΩ.
- Cypress reommends:
- Electrical Charateristic
VIH : 1.4V , VIL : 0.45V
- Figure1.
- Figure2.
- Question
1. In Figure1, PMODE0 drops to 1.2V.
1.2V is lower than VIH(1.4V).
Is this OK?
2. In Figure2, PMODE0 drops to 1.7V.
This is higher than VIH.
For stable status, should I use 1Kohm Pull-up(PMODE0)/ 0ohm Pull-down(PMODE2) ?
jaehyuk choi 님이 메시지를 편집했습니다.
Solved! Go to Solution.
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Hello,
The dip and spike that you see are expected. After Reset, we enable a weak pull up followed by pull down internally in the PMODE pins to check whether the PMODE Pin is in High-Z, High or Low state. Initially, a weak pull up is enabled and we wait for about 6us during which the state of the pin is sampled. Then we enable a pull down and wait for 6us.
Because of this, you find a 0.25V spike first for 6us and then a dip to 1.2V for 6us. This is an expected behaviour. This will not affect the functionality.
Best Regards,
Jayakrishna
Jayakrishna