Description
This product evaluation board is based on STMicroelectronics' PM6644. The device combines a 350 mA valley current limit step-down regulator with a high accuracy 3.3 V voltage reference in a small DFN10 3x3 package. The switching regulator is based on a CoT (constant on time) architecture that assures fast load transient response. The embedded voltage feed-forward provides nearly constant switching frequency operation. Pulse-skipping is employed to increase efficiency at very light load. The switching frequency can be adjusted from 200 kHz to 600 kHz by means of a simple resistor. The switching regulator can be programmed to regulate a fixed value of 3.43 V or it can deliver an adjustable voltage, depending on the FB pin setup. The high precision integrated 3.3 V reference can source up to 5 mA.