Exhibit 99.1 Power Integrations Reports First-Quarter Financial Results Revenues increased 15 percent year-over-year to $105.5 million; GAAP earnings were$0.15 per diluted share; non-GAAP earnings were $0.31 per diluted share New$50M share-repurchase authorization follows completion of prior $50M buyback SAN JOSE, CALIF. – May 12, 2025 – Power Integrations (NASDAQ: POWI) today announced financial results for the quarter ended March 31, 2025. Net revenues for the first quarter were$105.5 million, up sligh ...