The devices are designed to provide a wide 5V to 40V input voltage range while providing excellent transient response and output accuracy over the entire voltage range using Exar's emulated current mode Constant On-Time (COT) control loop. These devices deliver power to a wide range of industrial and networking equipment typically powered by well-regulated 24 VDC, classical telecom 18V to 36V, or 24 VAC supplies.
The regulators provide fast line and load transient response using ceramic output capacitors. They require no loop compensation, simplifying circuit implementation and reducing overall component count. The control loop also provides 0.07% load and 0.15% line regulation and maintains constant operating frequency. A selectable power saving mode allows the device to operate in discontinuous mode (DCM) at light current loads, increasing the converter efficiency. Protection features, including overcurrent, over-temperature, short-circuit and UVLO, help achieve safe operation under abnormal operating conditions.
Jon Cronk, Exar’s director of marketing for power products, asserts, "Exar's proprietary emulated current mode architecture sets it apart from competition in terms of load and line regulation and transient response. The common 5 x 5 mm package size allows designers to easily scale across a wide range of power levels."
The XR76203, XR76205 and XR76208 are available in RoHS compliant, green/halogen free, space-saving 30-pin 5 x 5 mm QFN packages. The XR76203, XR76205 and XR76208 are priced at $1.85, $2.30 and $2.90, respectively (1000).