Here is a quick overview of the capacitive touch-sensing solution (CapSense) available in the PSoC 6 device family. Cypress’ PSoC 6 device family features the 4th generation CapSense solution along with enhanced performance and flexibility for system integration.
The key features are:
- Supports both self-cap and mutual-cap sensing methods on a single chip.
- Self-cap sensing based designs are simpler, lower in cost, and work on a single layer (PCB) sensor stack-up.
- Self-cap sensing provides faster refresh rates and long distance field projections, enabling sensing through thick overlays and various glove materials, and can help implement hover effects.
- Self-cap sensing is ideal for proximity sensing, enabling system-level ultra-low-power designs. For example, the system can remain in an extremely low-power state with only a proximity sensor activated to wake the system from a low-power state when a user is near to or approaching the system.
- Mutual-cap sensing is ideal for sensor designs with higher parasitic capacitances such as sensors on a large front panel or on a flex PCB, where multiple PCB layers are stacked very near to each other.
- Mutual-cap sensing provides superior touch accuracy and enables multi-touch sensing.
- Cypress’ CapSense solution provides APIs to quickly and dynamically switch between self-cap and mutual-cap sensing methods in the same application, enabling you to exploit the best of both the worlds.
- Self-cap and mutual-cap sensing on a single chip greatly benefits optimizing system-level power and enhances robust system performance, superior noise-immunity, rejecting spurious conditions, and implementing wet finger tracking, liquid tolerance, etc.
- Purpose built
- The PSoC 6 device family offers best-in-class CapSense for user interfaces, ultra-low-power LCD drive for displays, world class BLE for connectivity and CRYPTO for embedded security on a single chip – an attractive solution for IoT, wearables, and industrial products.
- A Single-chip solution provides advantages for solving system integration issues such as interference between CapSense and BLE or LCD drives.
- CapSense can perform scanning without either of the CPUs (CM0+ and CM4 cores) and can work in parallel with all other peripherals on the chip.
- Noise reduction techniques such as multi-frequency scanning and spread spectrum clocking do not affect system clocks and other peripherals that require precision timing.
- A 10-bit ADC is also available within the CapSense hardware block, enabling measurement of slow-changing signals, such as battery voltages.
- A linear-feedback shift register based spread spectrum clock offers superior immunity against external noise sources and reduced radiated emission levels.
- In addition to all the above, the industry leading Cypress CapSense solution offers superior SNR > 300:1, which delivers robust noise immunity, liquid tolerance, and proximity detection.
- CapSense solution is also capable of measuring capacitance ranging from femto-farads to pico-farads for any of your custom designs.