Claims
- 1. A semiconductor integrated circuit chip comprising:
- a semiconductor output device driving an external load;
- a sensor for sensing heat generated by said semiconductor output device, and
- a microprocessor unit including at least a memory, a counter and a CPU,
- wherein said semiconductor output device is a power MOSFET,
- wherein said sensor is a ring oscillator generating an oscillation signal, and oscillation frequency of which is dependent on said heat generated by said power MOSFET,
- wherein said oscillation signal of said ring counter is counted by said counter,
- wherein digital count data of said counter based on said oscillation signal of said ring oscillator is compared with a plurality of comparison levels by said CPU in accordance with a stored program of said memory, and
- wherein driveability of said power MOSFET is set at a selected one of a plurality of driveability levels corresponding to said plurality of comparison levels in accordance with a result of comparison of said digital count data with said plurality of comparison levels.
- 2. A semiconductor integrated circuit chip according to claim 1, further comprising:
- a first power supply terminal for supplying a supply voltage to said CPU from outside of the chip; and
- a second power supply terminal for supplying a supply voltage to said power MOSFET from outside of the chip.
- 3. A semiconductor integrated circuit chip; comprising:
- a semiconductor output device driving an external load;
- a sensor for sensing heat generated by said semiconductor output device, and
- a microprocessor unit including at least a memory, a counter and a CPU,
- wherein said sensor is a ring oscillator generating an oscillation signal, an oscillation frequency of which is dependent on said heat generated by said semiconductor output device,
- wherein said oscillation signal of said ring counter is counted by said counter,
- wherein digital count data of said counter based on said oscillation signal of said ring oscillator is compared with a plurality of comparisons levels by said CPU in accordance with a stored program of said memory, and
- wherein driveability of said semiconductor output device is set at a selected one of a plurality of possible driveability levels, corresponding to said plurality of comparison levels, in accordance with a result of comparison of said digital count data with said plurality of comparison levels.
- 4. A semiconductor integrated circuit chip according to claim 3, further comprising:
- a first power supply terminal for supplying a supply voltage to said CPU from outside of the chip; and
- a second power supply terminal for supplying a supply voltage to said semiconductor output device from outside of the chip.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2-295320 |
Nov 1990 |
JPX |
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Parent Case Info
This application is a continuation of application Ser. No. 785,808, filed on Oct. 31, 1991, now abandoned.
US Referenced Citations (12)
Non-Patent Literature Citations (1)
Entry |
"A Smarter Bipolar Stepper Motor Driver" PCIM'88 Proceedings by Gilles Troussel pp. 23-31. |
Continuations (1)
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Number |
Date |
Country |
Parent |
785808 |
Oct 1991 |
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