PMP7993.2: ±5 @ 100mA, ±15V @ 50mA, 7 ~ 32V in

This Flybuck reference design uses the LM5017 buck regulator to generate four isolated outputs: ±15V@50mA and ±5V@100mA. The regulation is done on the primary side, and thus no opto-coupler is needed. The overall load/line regulation for each output is within +/-5%. The input voltage range is from 17V to 32V. It's suitable for applications requiring multiple positive and negative bias voltage rails.

The LM5017 is a 100 V, 600 mA synchronous step- down regulator with integrated high side and low side MOSFETs. The constant-on-time (COT) control scheme employed in the LM5017 requires no loop compensation, provides excellent transient response, and enables very low step-down ratios. The on-time varies inversely with the input voltage resulting in nearly constant frequency over the input voltage range. A high voltage startup regulator provides bias power for internal operation of the IC and for integrated gate drivers.