Would you inform us what are threshold voltages(high and low) for single-end inputs(AP and BP)?
Are they Input High Voltage and Input Low Voltage in Electrical Specifications in the data sheet?
Are their value correct?
+/-50mV difference is a safe operation spot for AP-BP or SP-SN. Below that, you might see some SNR degradation.
Input voltage range is Vcc-0.1 to Vcc-0.5 (3.2 to 2.8 for Vcc=3.3) for AP and BP.
You should not exceed Vcc - 2.0 V to Vcc + 0.5 range for input voltages.
Are AP,BP single end input, right?
what do you mean "+/-50mV difference is a safe operation spot for AP-BP" ?
If they are single-end input, do they have threshold voltage for Low/High?
would you teach me when input (AP or BP) is recognized as High or Low?
AP and BP are positive inputs of differential CML interface. These pins can be used single ended also if you terminate AN and BN to Vcc with 50ohms. At equilibrium state, CML input voltages wait idle at 3.1V. When the input (AP or BP) are pulled down to 2.9V, the state goes 0 and when pulled up to 3.3V, the state goes 1