Other Parts Discussed in Thread: ADS7138, TPS22918
The switch device of TPS22918 is used for switching of AVDD power for ADS7138 ADC IC, in the signal measurement block circuit of a control PCBA project, simplified circuit diagram of which is shown below.
The VOUT pin of TPS22918, which is connected to QOD pin and AVDD pin of ADS7138 provides switching for AVDD power for four devices of ADS7138.
One question raised by one of design reviewers.
Is worst case max QOD pin current during RESET state (while QOD is pulled to GND) compatible with the limit for stable operation?
I have calculated worst case max steady state current of QOD pin to find it is lower than 35mA.
Is it OK?
What is limit of QOD current for Ta = -40C to 85C?
AVDD trace has 4uF capacitance (4 IC x 1uF / IC).