The RT3661ABGQW with Switching Controllers WQFN5x5-40 RoHS is an integrated monolithic multimode boost controller IC manufactured by Richtek. This IC is designed to provide constant Voltage (CV) or Current (CC) mode operation. It can be used for applications such as power supplies, LED lighting, and automotive applications. The RT3661ABGQW Switching Controller is compatible with the existing WQFN5x5-40 RoHS package. It has a low start-up current of 1.5 µA, set-point accuracy of ±2 %, and an allowance for soft-start. It can be used with an external loop compensation circuit for better load regulation and transient response. The RT3661ABGQW also features a wide input voltage range from 3 V to 38 V and a low operating quiescent current of 75 µA. The device is AEC-Q100 qualified for automotive applications and is compliant to RoHS directive 2011/65/EU.