I have 2 issues with the TSC2007:
1. After a couple of minutes, the SCL line gets stuck in low. I tried several things to solve this issue: I reduced the SCL clock frequency to about 74kHz, so there is no need for the TSC2007 to stretch the clock ever. I also tried a couple of different configurations, like power down between cycles and ADC converters always on, but the SCL line still gets stuck low. What can cause the TSC2007 to exhibit such a behavior?
2. I am sometimes getting erroneous readings, meaning too large numbers. I am expecting numbers in the range of about 400 when I am reading the X coordinate, but sporadically I am getting numbers in the range of 3000 thrown into the data stream. This happens also when I keep my finger pressed on the touch screen and just watch the numbers the TSC2007 spits out. I could not correlate anything to this behavior.
A little bit about my setup: I am communicating with the TSC2007 through a PCA9665A. VDD is 3.3V, decoupled with a 1µF capacitor and a 10µF Tantalium capacitor very close to the TSC2007. The SCL and SDA lines are pulled to 3.3V with 1.2kOhm resistors. The TSC2007 sits right next to the PCA9665A, so the SCL and SDA traces are only about 3/4" long. For diagnostic purposes I cut the SCL line, put a jumper in and added another (weak) pullup resistor. So I can disconnect the SCL line from the PCA9665A. Thus I was able to find out that the TSC2007 is keeping the SCL line low, not the PCA9665A. The PCA9665A supports clock stretching.
Any help is appreciated. I am already stuck with this issue for several days.