Semiconductor integrated circuit
First Claim
Patent Images
1. A semiconductor integrated circuit connected between a power supply and an inductive load, comprising:
- an output transistor controlling current flowing through the inductive load;
a clamp circuit clamping an overvoltage applied to the output transistor;
a reference signal generator circuit generating a reference signal by adjusting a level of a control signal input to a control electrode of the output transistor, said reference signal generator circuit comprising one of a time delay function and a hysteresis function; and
a clamp controlling circuit bringing the clamp circuit into operation based on the reference signal on condition that a counter electromotive force of the inductive load is applied to the output transistor.
3 Assignments
0 Petitions
Accused Products
Abstract
To provide an output MOS transistor from breaking due to dump surge and counter electromotive, a semiconductor integrated circuit according to an embodiment of the invention includes an output MOS transistor controlling current flowing through a load, a dynamic clamp circuit clamping an overvoltage applied to the output MOS transistor, a delay circuit generating a reference signal by adjusting a level of a gate voltage of the output MOS transistor, and a clamp controlling circuit making the dynamic clamp circuit operate based on the reference signal when a counter electromotive force is applied to the output MOS transistor.
-
Citations
15 Claims
-
1. A semiconductor integrated circuit connected between a power supply and an inductive load, comprising:
-
an output transistor controlling current flowing through the inductive load; a clamp circuit clamping an overvoltage applied to the output transistor; a reference signal generator circuit generating a reference signal by adjusting a level of a control signal input to a control electrode of the output transistor, said reference signal generator circuit comprising one of a time delay function and a hysteresis function; and a clamp controlling circuit bringing the clamp circuit into operation based on the reference signal on condition that a counter electromotive force of the inductive load is applied to the output transistor. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A semiconductor integrated circuit, comprising:
-
a high-side switching circuit driving an inductive load; a control signal generator circuit generating a control signal controlling a driving operation of the high-side switching circuit, said control signal generator circuit comprising one of a time delay function and a hysteresis function; a discharging circuit discharging the control signal to the inductive load under an off-state of the high-side switching circuit; and a counter electromotive force protective circuit protecting the high-side switching circuit from a counter electromotive force based on a reference signal obtained by decreasing slope of a rising edge or a falling edge of the control signal.
-
-
9. A semiconductor integrated circuit, comprising:
-
an output transistor connected between a power supply terminal supplied with power and an output terminal connected with an inductive load and operating in response to a control signal applied to a control terminal thereof; a clamp circuit connected between the control terminal and the power supply terminal; a reference signal generator circuit generating a reference signal by changing a level of the control signal, said reference signal generator circuit comprising one of a time delay function and a hysteresis function; and a clamp controlling circuit connected between the power supply terminal and the output terminal, and controlling an operation of the clamp circuit in accordance with the reference signal. - View Dependent Claims (10, 11, 12, 13, 14, 15)
-
Specification