Exhibit 99.1 Power Integrations Reports First-Quarter Financial Results Quarterly revenues were $91.7 million; GAAP earnings were $0.07 per diluted share; non-GAAP earnings were $0.18 per diluted share SAN JOSE, CALIF. – May 7, 2024 – Power Integrations (NASDAQ: POWI) today announced financial results for the quarter ended March 31, 2024. Net revenues for the first quarter were $91.7 million, up two percent from the prior quarter and down 14 percent from the first quarter of 2023. GAAP net income for the fi ...