High-side transistor driver for power converters

1. A driver, comprising:

a high-side transistor;

a low-side transistor coupled to the high-side transistor;

a floating-ground terminal, connected to a source of said high-side transistor;

a floating-supply terminal, for providing a floating voltage for the high-side transistor driver ;

a charge-pump diode, having a cathode connected to said floating-supply terminal, wherein an anode of said charge-pump diode is supplied with a bias voltage;

a bootstrap capacitor, connected in series with said charge-pump diode, wherein a negative terminal of said bootstrap capacitor is connected to said floating-ground terminal, and wherein a positive terminal of said bootstrap capacitor is connected to said floating-supply terminal;

a p-transistor, having a source connected to said floating-supply terminal, ;

an n-transistor, having a source connected to said floating-ground terminal, wherein a gate of said n-transistor is connected to a gate of said p-transistor, wherein a drain of said n-transistor forms a junction with a drain of said p-transistor, and wherein the voltage at said junction drives a gate of said high-side transistor; and

a current sink, connected from the gate of said n-transistor to said floating-ground terminal, for continuously sinking current;

a control p - transistor, having a source connected to said floating - supply terminal, wherein said control p - transistor has a drain coupled to said gate of said n - transistor;

a first current source connected from said floating - supply terminal to a gate of said control p - transistor;

a first diode, having an anode connected to said floating - ground terminal, wherein said first diode has a cathode connected to said gate of said control p - transistor;

an on/off transistor, for switching said control p - transistor, wherein said on/off transistor has a drain connected to said gate of said control p - transistor, wherein a source of said on/off transistor is connected to the ground reference;

a first inverter, having an input supplied with an input signal, wherein said first inverter has an output connected to a gate of said on/off transistor; and

a speed - up circuit, having an output connected to said gate of said control p - transistor, wherein said input signal is supplied to an input of said speed - up circuit, and wherein said speed - up circuit is used for accelerating the charge - up of a parasitic capacitor of the on/off transistor.

2. The driver as claimed in claim 1 , wherein said bias voltage charges said bootstrap capacitor whenever said low-side transistor is turned on, wherein said bias voltage supplies said floating voltage at the floating-supply terminal whenever said low-side transistor is turned on.

3. The driver as claimed in claim 1 further comprising:

a control p-transistor, having a source connected to said floating-supply terminal, wherein said control p-transistor has a drain coupled to said gate of said n-transistor;

a first current source connected from said floating-supply terminal to a gate of said control p-transistor;

a first diode, having an anode connected to said floating-ground terminal, wherein said first diode having a cathode connected to said gate of said control p-transistor;

an on/off transistor, for switching said control p-transistor, wherein said on/off transistor has a drain connected to said gate of said control p-transistor, wherein a source of said on/off transistor is connected to the ground reference;

a first inverter, having an input supplied with an input signal, wherein said first inverter has an output connected to a gate of said on/off transistor; and

a speed-up circuit, having an output connected to said gate of said control p-transistor, wherein said input signal is supplied to an input of said speed-up circuit, and wherein said speed-up circuit has a capacitive coupling.

4. The driver as claimed in claim 3 1 , wherein said n-transistor is turned on and said high-side transistor is switched off whenever said control p-transistor is turned on.

5. The driver as claimed in claim 3 1 , wherein said current sink is utilized to turn on said p-transistor and switch on the high-side transistor whenever said control p-transistor is turned off.

6. The driver as claimed in claim 3 1 , wherein said first current source is utilized to charge up a parasitic capacitance of said on/off transistor and turn off said control p-transistor.

7. The driver as claimed in claim 3 1 , wherein said on/off transistor is turned off whenever said input signal is high.

8. The driver as claimed in claim 3 1 , wherein said speed-up circuit generates a control signal in response to said input signal, and wherein said control signal accelerates the charge-up of a parasitic capacitance of said on/off transistor and accelerates the turn-on of the high-side transistor.

9. The driver according to claim 3 1 , wherein said speed-up circuit comprises:

an accelerative p-transistor, having a source connected to said floating-supply terminal, wherein said accelerative p-transistor has a drain connected to said output of said speed-up circuit;

a second current source, connected from said floating-supply terminal to a gate of said accelerative p-transistor;

a second diode, having an anode connected to said floating-ground terminal, wherein said second diode has a cathode connected to said gate of said accelerative p-transistor;

a third diode, connected in series with said second diode, wherein said third diode has a cathode connected to said floating-supply terminal, and wherein said third diode has an anode connected to said gate of said accelerative p-transistor;

a capacitor, for switching said accelerative p-transistor; and

a second inverter, having an input connected to said input of said speed-up circuit, wherein said capacitor is connected from an output of said second inverter to said gate of said accelerative p-transistor.

10. The driver according to claim 9 , wherein said accelerative p-transistor charges up a parasitic capacitance of said on/off transistor whenever said accelerative p-transistor is turned on.

11. The driver according to claim 9 , wherein said accelerative p-transistor is turned on within a time-constant, wherein the length of the time-constant is proportional to the product of the amplitude of the current from said second current source and the capacitance of said capacitor.

12. A driver, comprising:

a charge - pump diode, supplied with a bias voltage;

a bootstrap capacitor, coupled to said charge - pump diode via a floating supply terminal, wherein a floating voltage is generated across said bootstrap capacitor in response to said bias voltage;

a drive circuit, coupled to said floating supply terminal, a high - side switch, and a floating - ground terminal, said drive circuit generating a switch signal in response to a control signal, for driving said high - side switch;

a speed - up circuit, comprising:

an accelerative switch, coupled to said floating - supply terminal and said output of said speed - up circuit;

a first current source, coupled to said floating - supply terminal and said accelerative switch;

a second diode, coupled to said floating - ground terminal and said accelerative switch;

a third diode, coupled to said second diode, said floating - supply terminal, said first current source, and said accelerative switch; and

a capacitor, for speeding up the turning on of said high - side switch according to said input signal.

13. The driver as claimed in claim 12 , wherein said driver further comprising a control circuit, said control circuit coupled to the said charge- pump diode, said floating - ground terminal and said drive circuit, wherein said control circuit generating said control signal in response to an input signal.

14. The driver as claimed in claim 13 , said control circuit comprising:

an on/off switch, coupled to a ground reference and said speed - up circuit, wherein said on/off switch generating a on/off signal in response to said input signal;

a second current source, coupled to said floating - supply terminal and said on/off switch;

a fourth diode, coupled to said floating - ground terminal, said second current source, and said on/off switch; and

a control switch, coupled to said second current source and said on/off switch, wherein said control switch generating said control signal in response to said on/off signal,

wherein a parasitic capacitance at a terminal of said on/off switch is charged - up by said speed - up circuit and said second current source.