Exhibit 99.1 Allegro MicroSystems Reports First Quarter 2027 Results First Quarter Sales Increased by 27% Year-over-Year to $259 Million Manchester, NH, July 30, 2026 – Allegro MicroSystems, Inc. ("Allegro" or the "Company") (Nasdaq: ALGM), a global leader in power and sensing semiconductor solutions for motion control and energy efficient systems, today announced financial results for its first quarter ended June 26, 2026. "We began fiscal 2027 with strong momentum, delivering our sixth consecutive quarter ...