Design of Combined PWM/PFM Controlled Boost Converter for Pulsed Doppler Ultrasound Transmitters

The paper presents a boost converter design for medical ultrasound transmitters, particularly applying to a pulsed Doppler ultrasound system. A dual mode controller is employed for the boost converter to maintain high efficiency over a wide load range. The device operates from a 3.3-V supply, capable of producing a 10V output DC voltage. Simulated results exhibit the capability of the designed boost converter can supply 500 mA maximum current with the peak efficiency over 92%, and achieves more than 75% efficiency with a light load of above 10 mA.