TSC2200: Touch controller IC support for performance improvement

Vihang Waze79

Part Number: TSC2200

Hi,

We need a technical support regarding the touch screen controller IC "TSC2200IPW" which we are using in our prototype development. Currently the performance test and rigorous test of our proto is in progress and shortly we will be approaching the manufacturing phase after one month from now.

Application:

Currently we are using this "TSC2200IPW" IC with LCD screen having resistive touch panel (RTP). The "TSC2200IPW" IC is interface with the main controller using the SPI interface along with "PENIRQ" and "DAV" signal as below image shown. We are using the IRQ request for detecting the touch. In our case, we are just using the 'X' and 'Y' co-ordinates data for our touch sensing functionality. In our application we are using fingers and do not have stylus,

Observation and Issue :

With the 'X' and 'Y' co-ordinates data from the touch IC, what we observe is, the touch is not sensitive with the fingers because we have to press two to three times on the touch screen panel and with little extra pressure to get the touch detected. This is affecting the performance criteria of our proto/product from user interface feature point of view.

Is there any method to improve the touch sensitivity through the touch controller IC "TSC2200IPW"? I went through the datasheet of the TSC2200IPW IC where it is mention of the 'Z' co-ordinates used for calculating the pressure of the touch. Will this 'Z' /pressure co-ordinate help in improving the touch sensitivity.

Or is there any calibration method which is standard for touch IC through which we can improve the touch sensitivity?.

Please help us on this. Appreciate your support

Regards,

Vihang Waze

11 months ago

0 Sanjay Dixit 11 months ago

TI__Mastermind 23020 points

As a starting point, can you please send me your schematic?

0 Vihang Waze79 11 months ago in reply to Sanjay Dixit

Prodigy 50 points

Hi Sanjay,

Due to confidentiality, I cannot share the complete design but whatever is related to the Touchscreen IC, I have shared below. I hope this helps you to understand.

Microcontroller section

Touch screen IC section

LCD Touch screen connector

Let me know any queries,

Regards,

Vihang Waze

0 Sanjay Dixit 11 months ago in reply to Vihang Waze79

TI__Mastermind 23020 points

1.Are the inductances in the schematic ferrite beads?

2. Are you using the PENIRQ to initiate operation? Have you seen the PENIRQ waveform when a touch is initiated?

0 Vihang Waze79 11 months ago in reply to Sanjay Dixit

Prodigy 50 points

Hi Sanjay,

1.Are the inductances in the schematic ferrite beads? Yes, the inductance in the schematics are ferrite beads - 742792693 - Descrp: 2.2 kOhms @ 100 MHz Signal Line Ferrite Bead 50mA 800mOhm

2. Are you using the PENIRQ to initiate operation? Yes, we are using PENIRQ to initiate operation.

Have you seen the PENIRQ waveform when a touch is initiated? Yes, we see the waveform when the we touch the resistive touch screen. But to get the waveform we have to apply a considerable amount of pressure on touch screen using finger to get the interrupt.

Regards,

Vihang Waze

0 Sanjay Dixit 11 months ago in reply to Vihang Waze79

TI__Mastermind 23020 points

shall respond in a short while

0 Sanjay Dixit 11 months ago in reply to Sanjay Dixit

TI__Mastermind 23020 points

Can you check waveform on X1 when attempting to activate PENIRQ?

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TSC2200: Touch controller IC support for performance improvement