Quad-channel digital isolator 4DIR1421H in DSO-16 wide-body package The 4DIR1421H (with 3 forward channels) provides robust reinforced isolation for high-voltage applications. Four data channels allow for simplified and high-power density designs and improve system efficiency with low power consumption. With a wide supply voltage range, active-low output enable and default high output state, it is a perfect fit for SPI communication interfaces where reinforced isolation is required