Tool/software:
Hi,
May I ask what the internal pull-down resistor value is for the LMKDB1204 vCLKIN_SEL_tri pin? What is the internal structure of this pin? Does the pull-up resistance vary with different VDD levels?
We plan to drive the CLKIN_SEL_tri pin with 3V3 / 1V8 / GND to select among the three modes when VDD = 3.3 V. However, we found that using a 10 kΩ pull-up to 3V3 causes the voltage to drop below VIH, so we’d like to confirm the IC’s internal resistance.
Below are the EVB validation results—please help confirm whether they are reasonable. Thank you.
EVB Test:
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VDD = 3V3, 10 kΩ pull-up to 3V3 → vCLKIN_SEL_tri = 1.53 V
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VDD = 1V8, 10 kΩ pull-up to 1V8 → vCLKIN_SEL_tri = 1.21 V
Thanks!
Jeff
