X0306 4 2019-02-22 0 0001038074 SILICON LABORATORIES INC SLAB 0001723770 Piovaccari Alessandro 400 W CESAR CHAVEZ AUSTIN TX 78701 0 1 0 0 Sr VP and CTO Common Stock, $0.0001 par value 2019-02-22 4 A 0 8220 0 A 34072 D Reflects the grant of restricted stock units (RSUs) that will entitle Reporting Person to receive one (1) share of common stock per RSU. One-third of the RSUs will vest on each of February 22, 2020, February 15, 2021, and February 15, 2022 and will be settled pursuant to the terms of the Issuer's 2009 Stock Incentive Plan as amended and restated on April 20, 2017. Saie-Yau Hui for Alessandro Piovaccari 2019-02-25