D-optimized switching converter

摘要

A switching converter produces an output signal transmitted to a variable load impedance to produce a load voltage V_DD across the load impedance and holds V_DD close to a set point voltage V_SP selected by control data D_REF1 to compensate for variations in the load impedance which tend to drive V_DD away from V_SP. The switching converter includes a pulse-width modulated power converter for producing the output signal of voltage V_OUT in response to an input signal of voltage V_IN, wherein a ratio V_OUT/V_IN is a function of a duty cycle D₁ of a pulse-width modulated signal V_PWM1. A pulse-width modulation circuit generates the V_PWM signal of duty cycle D₁ controlled by a control signal, and a feedback control circuit monitoring the load voltage V_DD adjusts D₁ to keep the load voltage as close as possible to V_SP. A power source supplies the input signal of voltage V_IN to the power converter. Second control data supplied to the power source separately selects the value of V_IN for each possible set point voltage V_SP such that that the pulse-width modulate signal's duty cycle D₁ remains as close a possible to a value for which circuit performance is substantially optimal with respect to a selected combination of performance criteria.