To begin the design process, determine the following:
- Input voltage range
- Use the supply voltage of the device that is driving the TXS0104E device to determine the input voltage range. For a valid logic high the value must exceed the VIH of the input port. For a valid logic low the value must be less than the VIL of the input port.
- Output voltage range
- Use the supply
voltage of the device that the TXS0104E device is
driving to determine the output voltage range.
- The TXS0104E device has 10-kΩ internal pullup
resistors. External pullup resistors can be added to reduce the
total RC of a signal trace if necessary.
- An external pull down resistor decreases the output VOH and VOL. Use Equation 1 to calculate the VOH as a result of an external pull down resistor.
Equation 1.
where
VCCx is the supply voltage on either VCCA or VCCB
RPD is the value of the external pull down resistor