Granted Patent B2

US 7,362,147 · App. 11/450,299 · Granted Apr 22, 2008

Abstract

Claims (37)

1. An integrated circuit comprising:

an output stage transistor having a gate electrode;

a gate terminal for applying a drive signal to control a turning on and off of the output stage transistor;

a charge transistor, which, when the output stage transistor is turned on, supplies the gate electrode of the output stage transistor with a charging current;

a discharge transistor, which, when the output stage transistor is turned off, supplies the gate electrode of the output stage transistor with a discharge current; and

a turn-off control unit, which, when the output stage transistor is turned off, supplies the gate electrode with an additional discharge current during a first time interval and turns off the additional discharge current after the first time interval, the turn-off control unit comprising:

a voltage determination unit for determining a voltage at the drain electrode of the output stage transistor, the voltage determination unit emitting a drain voltage signal on the basis of the voltage present at the drain electrode of the output stage transistor;

a turn-off control logic unit, which receives the drive signal and the drain voltage signal and on the basis thereof generates a discharge current control signal;

a transmission gate that is driven by the discharge current control signal; and

a bipolar fast-discharge transistor, whereby the transmission gate is looped in series with the collector-emitter section of the fast-discharge transistor between the gate electrode of the output stage transistor and a reference potential or ground.

2. The integrated circuit according to claim 1 , wherein a turn-on control unit, which, when the output stage transistor is turned on, supplies the gate electrode with an additional charging current during a second time interval and turns off the additional charging current after the second time interval.

3. The integrated circuit according to claim 2 , wherein the turn-on control unit comprises:

a switching state determination unit for determining a switching state of the output stage transistor, the switching state determination unit emitting a switching state signal dependent on the switching state of the output stage transistor;

a turn-on control logic unit, which receives the drive signal and the switching state signal and depending thereon generates a charging current control signal; and

a fast-charge transistor, which is driven by the charging current control signal, for providing the additional charging current, the fast-charge transistor being looped between a supply voltage and the gate electrode of the output stage transistor.

4. The integrated circuit according to claim 3 , wherein the switching state determination unit comprises:

a first sensor transistor whose gate electrode is connected to the gate electrode of the output stage transistor; and

a first sensor current source being looped in series with the drain-source section of the first sensor transistor between the supply voltage and a reference potential or ground, wherein the switching state signal is present at the drain electrode of the first sensor transistor (T 2 ).

5. The integrated circuit according to claim 1 , wherein the voltage determination unit comprises:

a second sensor transistor, whose gate electrode is connected to the supply voltage; and

a second sensor current source, whereby the drain-source section of the second sensor transistor and the second sensor current source are looped in series between the drain electrode of the output stage transistor and a reference potential or ground, and the drain voltage signal is present at the source electrode of the second sensor transistor.

6. The integrated circuit according to claim 1 , wherein the turn-off control unit comprises:

a fast-discharge release transistor;

a fast-discharge release transistor drive unit for driving the fast-discharge release transistor, which receives a voltage present at the base electrode of the fast-discharge transistor and as a function thereof switches on or blocks the fast-discharge release transistor; and

a fast-discharge current source, wherein a drain-source section of the fast-discharge release transistor and the fast-discharge current source are looped in series between the base electrode of the fast-discharge transistor and a reference potential or ground.

7. The integrated circuit according to claim 1 , wherein the turn-off control unit comprises:

an integration capacitor; and

an integration current source, wherein an integration capacitor and an integration current source are looped in series between the drain voltage signal and a reference potential or around, and a connecting node between the integration capacitor and the integration current source is connected to the base electrode of the fast-discharge transistor.

8. The integrated circuit according to claim 1 , further comprising:

a pull-down resistor, which is looped between the gate electrode of the output stage transistor and a reference potential or ground; and

a compensation unit that compensates for a current, caused by the pull down resistor, from the gate electrode to the reference potential.

9. The integrated circuit according to claim 8 , wherein the compensation unit comprises:

a sensor resistor, whose electrical properties coincide substantially with the electrical properties of the pull-down resistor;

a voltage follower unit, which taps off the voltage present at the pull-down resistor in a high-impedance manner and applies it to the sensor resistor in a low-impedance manner;

a current measuring unit, which measures the current flowing through the sensor resistor; and

a controlled compensation current source for supplying a compensation current to the gate electrode of the output stage transistor.

10. The integrated circuit according to claim 1 , wherein the output stage transistor is a MOS output stage transistor.

Assignments (11)