Exar - Integrated step-down COT regulators for point-of-load supplies (XR76203/5/8)

The Exar XR76203 / 5/8 synchronous buck constant on-time (COT) regulator combines the controller, driver, bootstrap diode and MOSFET in one package to provide point-of-load power. The rated load currents of these devices are 3A (XR76203), 5A (XR76205) and 8A (XR76208), respectively. The device has a wide input voltage range of 5V to 40V, allowing single power supply from industry standard 24V ± 10%, 18V-36V and rectified 18VAC and 24VAC power rails. With a proprietary simulated current mode COT control scheme, they use ceramic output capacitors to provide extremely fast line and load transient response. The device does not require loop compensation, which simplifies circuit implementation and reduces the total number of components. A series of protection functions, including overcurrent, overheat, short circuit and UVLO, help to achieve safe operation under abnormal operating conditions.