Tank capacitor charging for pulsed load applications
A power system for powering a pulsed load that intermittently delivers current pulses can include: an energy reservoir; a first DC-DC converter having an input that receives an input voltage and an output coupled to the energy reservoir; a second DC-DC converter having an input coupled to the energy reservoir and an output couplable to the pulsed load; and control circuitry that operates the first DC-DC converter to charge the energy reservoir from a minimum or valley voltage to a maximum or peak voltage during a charging window just prior to a current pulse of the pulsed load so that the first DC-DC converter is at or near its maximum output current at a beginning of the current pulse of the pulsed load.
1 . An electronic device power system that powers a pulsed load that intermittently delivers current pulses, the power system comprising:
a tank capacitor for storing energy to deliver the current pulses of the pulsed load;
a boost converter having an input that receives an input voltage and an output coupled to the tank capacitor;
an additional converter having an input coupled to the tank capacitor and an output couplable to the pulsed load; and
control circuitry that operates the boost converter to charge the tank capacitor from a minimum or valley voltage to a maximum or peak voltage during a charging window just prior to a current pulse of the pulsed load so that the boost converter is at or near its maximum output current at a beginning of the current pulse of the pulsed load, the control circuitry comprising:
circuitry responsive to a strobe signal indicating a timing of the current pulse and a control error signal to generate drive signals for one or more switching devices of the boost converter;
circuitry responsive to one or more additional signals to alter timing of the charging window; and
circuitry responsive to one or more additional signals to modulate a setpoint of the maximum or peak voltage of the tank capacitor responsive to the maximum or peak voltage.
2 . The electronic device power system of claim 1 wherein the circuitry responsive to one or more additional signals to alter timing of the charging window includes circuitry that monitors the minimum or valley voltage of the tank capacitor and increases or decreases the length of the charging window in response thereto.
3 . The electronic device power system of claim 2 wherein the circuitry that monitors the minimum or valley voltage of the tank capacitor and increases or decreases the length of the charging window in response thereto includes a hysteretic comparator.
4 . The electronic device power system of claim 1 wherein the circuitry responsive to one or more additional signals to modulate a setpoint of the maximum or peak voltage of the tank capacitor responsive to the maximum or peak voltage includes a hysteretic comparator.
5 . The electronic device power system of claim 1 wherein the circuitry responsive to one or more additional signals to modulate a setpoint of the maximum or peak voltage of the tank capacitor responsive to the maximum or peak voltage includes a linear feedback shift register.
6 . A controller for a power system that powers a pulsed load that intermittently delivers current pulses, the controller comprising control circuitry configured to operate a DC-DC converter to charge an energy reservoir from a minimum or valley voltage to a maximum or peak voltage during a charging window just prior to a current pulse of the pulsed load so that the DC-DC converter is at or near its maximum output current at a beginning of the current pulse of the pulsed load, wherein the control circuitry comprises circuitry responsive to a strobe signal indicating a timing of the current pulse and a control error signal to generate drive signals for one or more switching devices of the DC-DC converter.
7 . The controller of claim 6 wherein the energy reservoir is a tank capacitor, and the DC-DC converter is a boost converter.
8 . The controller of claim 6 further comprising circuitry responsive to one or more additional signals to alter timing of the charging window.
9 . The controller of claim 8 wherein the circuitry responsive to one or more additional signals to alter timing of the charging window includes circuitry that monitors the minimum or valley voltage of the energy reservoir and increases or decreases the length of the charging window in response thereto.
10 . The controller of claim 8 further comprising circuitry responsive to one or more additional signals to modulate a setpoint of the maximum or peak voltage of the energy reservoir responsive to the maximum or peak voltage.
11 . A power system for powering a pulsed load that intermittently delivers current pulses, the power system comprising:
an energy reservoir;
a first DC-DC converter having an input that receives an input voltage and an output coupled to the energy reservoir;
a second DC-DC converter having an input coupled to the energy reservoir and an output couplable to the pulsed load; and
control circuitry that operates the first DC-DC converter to charge the energy reservoir from a minimum or valley voltage to a maximum or peak voltage during a charging window just prior to a current pulse of the pulsed load so that the first DC-DC converter is at or near its maximum output current at a beginning of the current pulse of the pulsed load.
12 . The power system of claim 11 wherein the energy reservoir is a tank capacitor, the first DC-DC converter is a boost converter, and the second DC-DC converter is a buck converter.
13 . The power system of claim 11 wherein the control circuitry comprises circuitry responsive to a strobe signal indicating a timing of the current pulse and a control error signal to generate drive signals for one or more switching devices of the first DC-DC converter.
14 . The power system of claim 13 further comprising circuitry responsive to one or more additional signals to alter timing of the charging window.
15 . The power system of claim 14 wherein the circuitry responsive to one or more additional signals to alter timing of the charging window includes circuitry that monitors the minimum or valley voltage of the energy reservoir and increases or decreases the length of the charging window in response thereto.
16 . The power system of claim 14 wherein the circuitry that monitors the minimum or valley voltage of the energy reservoir and increases or decreases the length of the charging window in response thereto includes a hysteretic comparator.
17 . The power system of claim 13 further comprising circuitry responsive to one or more additional signals to modulate a setpoint of the maximum or peak voltage of the energy reservoir responsive to the maximum or peak voltage.
18 . The power system of claim 17 wherein the circuitry responsive to one or more additional signals to modulate a setpoint of the maximum or peak voltage of the energy reservoir responsive to the maximum or peak voltage includes a hysteretic comparator.
19 . The power system of claim 18 wherein the circuitry responsive to one or more additional signals to modulate a setpoint of the maximum or peak voltage of the energy reservoir responsive to the maximum or peak voltage includes a linear feedback shift register.
20 . The power system of claim 17 wherein the circuitry responsive to one or more additional signals to modulate a setpoint of the maximum or peak voltage of the energy reservoir responsive to the maximum or peak voltage includes a linear feedback shift register.