------Question for 74HC4051D Please Put your question below------
For the Toshiba 74HC4051D (SOP-16), we measured the impedance of pin 5 to GND and found it to be normal. When this pin is pulled up to VCC through a 20 kΩ resistor, the voltage continuously fluctuates between 2.3 and 2.7 VDC, whereas under normal conditions it should be 3.5 VDC.
Why did this happen?
The '4051 is an analog multiplexer, designed to connect a common pin to one of 8 others under control of several logic inputs. Pin 5 being one of the selectable input/output pins, its expected behavior would depend on the state of the control inputs, which is not mentioned in the question.
Additional information detailing the test setup, measurement conditions, and reason(s) for the stated expectations would be necessary to offer further comment.
