I am implementing the TSC2007 touch screen controller on a 4-wire screen. The part works great until we preform and ESD test. The screen is connected to the chassis and the circuit board ground with the TSC2007 chip is connected to the chassis. Some ESD discharges have no effect on the chip. Some times the TSC2007 chip will assert the interrupt, PENIRQ, and not release it after the I2C bus has read the registers. There is nothing touching the screen. The ESC2007 specification states that the chip has Enhanced ESD protection. The ground pin is connected to the internal circuit board ground plane that is connected to the chassis in mulitple places. The power pin is connected to an internal power plane. There are de-coupling capacitors on the power pin and elsewhere on the circuit board. Adding series resistors to the X+, X-, Y+ and Y- inputs reduces the ESD problem but does not eliminate it. The resistors create a touch calibration challenge as the resistance in the touch screens can very greatly from one screen to the next. Is there a way to reset the chip through the I2C bus? Currently only a power cycle will recover the problem.
The only reset scheme on TSC2007 is the power-on-reset (POR). The TSC may not be able to go back to its default working condition if the POR could not be implemented properly.
During the ESD test, the power supply to the TSC2007 might have big glitches that could lead to unexpected power on/off on the TSC. If so, there may be a POR problem, refer to sbaa161.
Another option is to shift to TSC2017, an upgraded version of the TSC2017 with the fixed on the TSC2007 POR problem.
Thank you for the additional information on the TSC2007. We have implemented some additional ESD shielding to the touch screen. That has resolved the issue. I did look for the TSC2017 at some distributors but there is no stock and lead times are weeks out so that makes it hard to be able to test that solution.
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