SLVT246 April 2026
This reference design is a tiny three channel isolated bias supply based on Flyback topology. Providing the voltage supply for isolated gate drivers is a typically use case. The design integrates three 21V, 2W isolated outputs and one 7V non-isolated auxiliary output. The design uses a planar transformer integrated into the printed circuit board (PCB) to reduce the board height and system cost. The LM5158-Q1 converter supports primary-side regulation (PSR) by using an auxiliary winding on the primary side. The maximum efficiency is 88%.