METHOD AND APPARATUS FOR DC-TO-DC CONVERSION

• US 20110316511A1
• Filed: 04/22/2011
• Published: 12/29/2011
• Est. Priority Date: 06/24/2010
• Status: Abandoned Application

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Inventors: Wang, Meng, Jiang, Song
• Application Number:
  US13/092,164
• Publication Number:
  US 20110316511A1
• Time in Patent Office: Days
• US Class Current: 323/285
• CPC Class Codes: H02M 1/0022 the disturbance parameters being input voltage fluctuations
• CPC Class Codes: H02M 3/156 with automatic control of output voltage or current, e.g. switching regulators
• CPC Class Codes: H03K 3/017 Adjustment of width or dutycycle of pulses pulse width modulation H03K7/08 ; to maintain energy constant H03K3/015

Abstract

A direct current-to-direct current (‘DC-DC’) converter generates a pulse-width modulated (‘PWM’) control signal, and generates an output voltage from an input voltage as a function of a duty cycle of the PWM control signal. A feed-forward module controls both the duty cycle and a repetition rate of the PWM control signal as regressive functions of the input voltage so as to tend to compensate for variation in the input voltage.

Claims

1. A direct current-to-direct current (‘

DC-DC’

) converter, comprising;

a control signal generator for generating a pulse-width modulated (‘

PWM’

) control signal; and

an output voltage generator for generating an output voltage from an input voltage as a function of a duty cycle of said PWM control signal,

wherein said control signal generator comprises a feed-forward module for controlling both said duty cycle and a repetition rate of said PWM control signal as regressive functions of said input voltage to compensate for variation in said input voltage.

2. The DC-DC converter of claim 1, wherein said feed-forward module comprises a periodic signal generator for generating a periodic signal whose amplitude is a progressive function of said input voltage and whose repetition rate is a regressive function of said input voltage, and a comparator for comparing said periodic signal with a reference signal and producing a comparator output for controlling said duty cycle to compensate for variation in said input voltage.

3. The DC-DC converter of claim 2, wherein said periodic signal generator comprises a saw-tooth signal generator for generating said periodic signal as a saw-tooth signal whose peak value is a progressive function of said input voltage.

4. The DC-DC converter of claim 3, wherein said saw-tooth signal generator comprises a capacitor, a current source that is a progressive function of said input voltage for charging said capacitor, and a path for periodically discharging said capacitor.

5. The DC-DC converter of claim 2, wherein said periodic signal generator comprises an oscillator whose repetition rate is a regressive function of said input voltage for controlling said repetition rate of said periodic signal.

6. The DC-DC converter of claim 2, wherein said control signal generator includes a feedback module for generating said reference signal as a function of said output voltage to compensate for variation in said output voltage.

7. The DC-DC converter of claim 6, wherein a relationship between said duty cycle and said input voltage is of the form:

8. A direct current-to-direct current (‘

DC-DC’

) converter, comprising;

a control signal generator for generating a pulse-width modulated (‘

PWM’

) control signal; and

an output voltage generator for generating an output voltage from an input voltage as a function of a duty cycle of the PWM control signal,

wherein the control signal generator comprises,

a feed-forward module for controlling both the duty cycle and a repetition rate of the PWM control signal as regressive functions of the input voltage to compensate for variation in the input voltage,

wherein the feed-forward module comprises a periodic signal generator for generating a periodic signal whose amplitude is a progressive function of the input voltage and whose repetition rate is a regressive function of the input voltage, and a comparator for comparing the periodic signal with a reference signal and producing a comparator output for controlling the duty cycle to compensate for variation in the input voltage, and

wherein the periodic signal generator comprises a saw-tooth signal generator for generating the periodic signal as a saw-tooth signal whose peak value is a progressive function of the input voltage.

9. The DC-DC converter of claim 8, wherein said saw-tooth signal generator comprises a capacitor, a current source that is a progressive function of said input voltage for charging said capacitor, and a path for periodically discharging said capacitor.

10. The DC-DC converter of claim 8, wherein said periodic signal generator comprises an oscillator whose repetition rate is a regressive function of said input voltage for controlling said repetition rate of said periodic signal.

11. A method of direct current-to-direct current (‘

DC-DC’

) conversion, comprising;

generating a pulse-width modulated (‘

PWM’

) control signal;

generating an output voltage from an input voltage as a function of a duty cycle of said PWM control signal; and

controlling both said duty cycle and a repetition rate of said PWM control signal using feed-forward control as regressive functions of said input voltage to compensate for variation in said input voltage.

12. The DC-DC conversion method of claim 11, wherein generating said PWM control signal includes generating a periodic signal whose amplitude is a progressive function of said input voltage and whose repetition rate is a regressive function of said input voltage, and controlling said duty cycle includes comparing said periodic signal with a reference signal to compensate for variation in said input voltage.

13. The DC-DC conversion method of claim 12, wherein said periodic signal is a saw-tooth signal whose peak value is a progressive function of said input voltage.

14. The DC-DC conversion method of claim 13, wherein generating said saw-tooth signal comprises charging a capacitor using a current that is a progressive function of said input voltage, and periodically discharging said capacitor.

15. The DC-DC conversion method of claim 12, wherein generating said periodic signal includes using an oscillator to generate a signal whose frequency is a regressive function of said input voltage for controlling said repetition rate of said periodic signal.

16. The DC-DC conversion method of claim 12, wherein the reference signal is generated using feedback control as a function of said output voltage to compensate for variation in said output voltage.

17. The DC-DC conversion method of claim 16, wherein a relationship between said duty cycle and said input voltage is of the form: