Abstract: An illustrative controller embodiment includes: a transmitter that causes reverberation of a piezoelectric transducer; and a linear damping module that measures characteristics of the reverberation and tunes at least one of a shunt resistance and a shunt reactance for the piezoelectric transducer based on said characteristics. An illustrative sensor embodiment includes: a piezoelectric transducer; and a transducer controller coupled to the piezoelectric transducer to transmit pulses and receive echoes for measuring distances. The controller includes a linear damping module with: a shunt resistance; a shunt inductance; and an optional switch that couples the shunt resistance and shunt inductance in parallel to the piezoelectric transducer to damp reverberation of the piezoelectric transducer after said transmit pulses. The controller measures at least one characteristic of said reverberation and responsively tunes the shunt resistance or the shunt inductance.

Abstract: A power converter has a power transistor and inductor coupled in a conduction path with the power transistor. A switching frequency of the power transistor is reduced during a light load condition. A pulse width of a drive signal to the power transistor is controlled to select a current through the inductor and power transistor corresponding to the switching frequency to maintain a fixed output power of the power converter, and further to vary the current through the inductor and power transistor to maintain the fixed output power of the power converter over a range of switching frequencies. A first number of pulses of the drive signal to the power transistor during a first time period sets the fixed output power of the power converter. No pulses of the drive signal are provided during a second time period after the first time period.

Abstract: A power converter has a power transistor and inductor coupled in a conduction path with the power transistor. A switching frequency of the power transistor is reduced during a light load condition. A pulse width of a drive signal to the power transistor is controlled to select a current through the inductor and power transistor corresponding to the switching frequency to maintain a fixed output power of the power converter, and further to vary the current through the inductor and power transistor to maintain the fixed output power of the power converter over a range of switching frequencies. A first number of pulses of the drive signal to the power transistor during a first time period sets the fixed output power of the power converter. No pulses of the drive signal are provided during a second time period after the first time period.