Control loop for switching power converters
First Claim
1. A regulation loop for a switching power converter of the type having a pulse width variable or pulse frequency variable modulator operating switches associated with a power source and a bridge filter section, with a power output node feeding a load, the variable parameter of the modulator establishing an amount of regulation and efficiency of the power converter, the bridge filter section having a first transfer function with inherent poles and zeros, the improvement comprising:
- a comparator having a high impedance first input sampling a voltage from the power output node of the switching power converter as a first input signal and having a second input signal from a reference supply representing a target voltage level for the load, the comparator having an output signal on an output line with a high or low signal depending on whether first input signal exceeds the second input signal or not; and
a filter connected to the comparator receiving the comparator output signal and to deliver a filter output signal, the filter having a second order transfer function, the second order transfer function established by a selection of filter components offsetting the poles and zeros of the first transfer function, whereby the filter output signal is smooth, operating the variable parameter of the pulse width variable or pulse frequency variable modulator.
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Accused Products
Abstract
A pulse regulation loop for a clocked switching power converter where the loop is around a bridge converter. The loop features a comparator, a charge pump and a filter in series, feeding a pulse modulator controlling the clock duty cycle of the bridge. Ripple in the bridge converter output is feed to the comparator which causes the charge pump to inject or remove charge from the filter at the clock rate providing control over the modulator that establishes converter efficiency. The charge pump is of the PLL type, having switches responsive to voltage output from the comparator, evaluating the converter ripple relative to a reference voltage.
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Citations
15 Claims
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1. A regulation loop for a switching power converter of the type having a pulse width variable or pulse frequency variable modulator operating switches associated with a power source and a bridge filter section, with a power output node feeding a load, the variable parameter of the modulator establishing an amount of regulation and efficiency of the power converter, the bridge filter section having a first transfer function with inherent poles and zeros, the improvement comprising:
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a comparator having a high impedance first input sampling a voltage from the power output node of the switching power converter as a first input signal and having a second input signal from a reference supply representing a target voltage level for the load, the comparator having an output signal on an output line with a high or low signal depending on whether first input signal exceeds the second input signal or not; and
a filter connected to the comparator receiving the comparator output signal and to deliver a filter output signal, the filter having a second order transfer function, the second order transfer function established by a selection of filter components offsetting the poles and zeros of the first transfer function, whereby the filter output signal is smooth, operating the variable parameter of the pulse width variable or pulse frequency variable modulator. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A regulation loop for a switching power converter of the type having a pulse width variable or pulse frequency variable modulator operating switches associated with a power source and a bridge filter section, with a power output node feeding a load, the variable parameter of the modulator establishing an amount of regulation and efficiency of the power converter, the improvement comprising:
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a comparator having a high impedance first input sampling a voltage from the power output node of the switching power converter as a first input signal and having a second input signal from a reference supply representing a target voltage level for the load, the comparator having an output signal on an output line with a high or low signal depending on whether first input signal exceeds the second input signal or not;
a charge pump connected to receive the output signal from the comparator and either source or sink current in response thereto as a current signal; and
a filter connected to the comparator receiving the current signal and delivering a filter output signal operating a pulse width variable or pulse frequency variable modulator. - View Dependent Claims (10, 11, 12, 13, 14, 15)
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Specification