US 11,996,847 B1 · Power transistor adaptive clamp circuit

Abstract

An adaptive clamp circuit includes a clamp circuit and a clamp control circuit. The clamp circuit includes a first transistor, a second transistor, and a variable resistor. The first transistor includes a first current terminal, a second current terminal, and a control terminal. The first current terminal is coupled to a switching terminal. The second current terminal is coupled to a ground terminal. The second transistor includes a first current terminal, a second current terminal, and a control terminal. The first current terminal of the second transistor is coupled to the control terminal of the first transistor. The second current terminal of the second transistor is coupled to the switching terminal. The variable resistor is coupled between the control terminal of the second transistor and the ground terminal. The clamp control circuit is coupled between the switching terminal and the variable resistor.

Claims22

Dependent claims

An adaptive clamp circuit, comprising:

a clamp circuit including:
a first transistor having:
a first current terminal coupled to a switching terminal;
a second current terminal coupled to a ground terminal;
and
a control terminal;
a second transistor having:
a first current terminal coupled to the control terminal of the first transistor;
a second current terminal coupled to the switching terminal;
and
a control terminal;
and
a variable resistor coupled between the control terminal of the second transistor and the ground terminal;
and
a clamp control circuit coupled between the switching terminal and the variable resistor.

12 more elements

An adaptive clamp circuit, comprising:

a clamp circuit configured to limit a voltage at a switching terminal, and including:
a variable resistor configured to set a threshold voltage for activation of the clamp circuit;
and
a clamp control circuit coupled to the clamp circuit, and including:
a current sense amplifier including:
a first input coupled to the switching terminal;
and
a second input coupled to a ground terminal;
the current sense amplifier configured to sense a current flowing between the switching terminal and the ground terminal;
and
the clamp control circuit configured to vary a resistance of the variable resistor responsive to a change in the current sensed by the current sense amplifier.

8 more elements

A DC-DC converter, comprising:

a high-side transistor including:
a first current terminal coupled to a power supply input terminal;
and
a second current terminal;
a low-side transistor including:
a first current terminal coupled to the second current terminal of the high-side transistor;
and
a second current terminal coupled to a ground terminal;
a clamp circuit coupled to the first current terminal of the low-side transistor, the clamp circuit configured to limit a voltage at the first current terminal of the low-side transistor, the clamp circuit including a variable resistor configured to set a threshold voltage for activation of the clamp circuit;
and
a clamp control circuit coupled between the low-side transistor and the clamp circuit, the clamp control circuit configured to vary a resistance of the variable resistor responsive to a change in a current flowing through the low-side transistor.

8 more elements

Dependencies are inferred from the claim text.

Power transistor adaptive clamp circuit

Life of this patent

Power transistor adaptive clamp circuit

Life of this patent

Abstract

Claims22