Several leading pen ODMs serving tier-1 PC OEMs are utilizing the CSAA2001 SoC to build active capacitive stylus based on USI and other protocols.
Cirel Systems’ stylus controller CSAA2001 for universal stylus initiative has seen strong market adoption, with several leading pen ODMs serving tier-1 PC OEMs utilizing the CSAA2001 SoC to build active capacitive stylus based on Universal Stylus Initiative (USI) and other protocols.
The IC draws on Cirel’s expertise in diverse domains ranging from power management ICs, signal processing, low-power sensor front ends, deep understanding of the USI specification, and stylus manufacturing flow, including pressure sensor calibration, all of which helped fast adoption of the IC.
“USI two-way communication between device and stylus requires due attention to the stylus receiver design to work well especially in noisy environments. Cirel’s novel receiver solution deploys advanced signal processing to make the pen receiver immune to noise,” commented Leela Madhav, Cirel’s Director of IC Design.
In addition, especially for the education market, it is important that super cap powered pens last for the duration of a class (about an hour) on a short 15s charge. This calls for ultra-low power solution, which has been a key differentiator for Cirel’s offering in this domain.
Vikas Agarwal, Director for Validation and Applications at Cirel, added, “Another challenge was supporting a myriad of designs with the same controller IC. While the IC was designed for supporting various power sources like Lithium ion battery, super capacitor or alkaline battery, seeing the concept through and working out all the details along with customers needed real time debug and close work with the customer’s engineering teams. Despite travel restrictions due to Covid, our applications team could work with partners across the world by providing real time support to its customers in Asia.”