Hi!
The datasheet of the DS90UB947-Q1 has changed quite a bit in March this year.
I inquire about this.
1. In the figure below(Mode Sel), it is shown that the value of R4 in mode sel 0 # 1 is less than 100k ohms, whatever it is. Is that right?
If so, is R3 being open and R4 being less than 100K ohm like # 1, is the measured VR4 voltage 0V?
Is it a complete pull down?
And if mode # 1 # 8 is a full pull up operation? Is the measured VR4 voltage 1.8V correct?
If possible, can you show me the internal circuitry of this pin for clarity?
2. In the figure below, in case of # 1 in the IDX setting, R1 is set to a value smaller than 100k ohms, and R2 is set to a fixed value of 40.2k ohms.
But how can the VR2 voltage be 0V? Calculating R1 at 99K ohms, the VR2 / Vdd18 ratio is 0.288 and Ideal VR2 is 0.519V.
If R1 is 82.73K and R2 is 40.2k ohms, the VR2 / Vdd18 ratio will be 0.327 which is the same as # 3.
Is this the coming of the datasheet or is the resistance setting of this # 1 correct?
If R1 is open and internal pull down, then this is going to make sense.
Please Check it.
Thank you
Best Regards
From Anthony.
