Monolithic active pixel detectors for tracking and calorimetry at e+e- colliders

The future Higgs Factory collider will provide unprecedented precision to significantly sharpen measurements and understanding of the Higgs boson. An attractive capability could come from using monolithic active pixel sensors (MAPS), which motivates our NAPA (Nanosecond timing Pixel for large Area sensors) detector development program for tracking and electromagnetic calorimetry.  We will report on test results of the prototypes and simulation studies of full detector performance.  The first, NAPA‑p1, was fabricated in 65 nm CMOS with a 1.5 mm × 1.5 mm footprint and 25 µm pitch. A second new design of NAPA‑p2 has been developed. To achieve an improvement in timing resolution and power efficiency over the current state-of-the-art, we are developing a compact, low-power Time-to-Digital Converter (TDC) and are working to integrate the full TDC into a MAPS pixel design, addressing the tight area, routing, and power constraints. The system level issues being addressed include cooling and power dissipation, power pulsing, multiple thresholds, bit depth, stitching, and mechanical design.