Design Overview
The ISOvolt isolated dc/dc reference design shown in Figure 1 is a low-cost, robust, isolated dc/dc converter capable of delivering a maximum of 3 W of output power. This isolated power converter enables Silicon Labs’ isolation products to be powered from a single bias supply, eliminating the need for separate supplies on both sides of the isolation device. This design features fold-back current limiting and thermal shutdown protection, low EMI operation, and high (78%) operating efficiency. Input voltage ranges are 3.3 or 4.5 Vdc to 5.5 Vdc and generate isolated output voltages of 3.3, 5.0, 7.0, or 24 V, depending on the transformer and output regulator used. Referring to Figure 1, the ISOvolt reference design is based on push-pull switching topology. The timing generator is a CT600-PX0624GM MCU, which has been factory-programmed to generate primary-side transformer switch timing.