Level shift circuit and semiconductor device
View Patent ↗A level shift circuit including a capacitor, a charge control circuit, and a limiting circuit. The charge control circuit is connected to the capacitor to provide the voltage of a high potential power supply to the capacitor and to control the charging of the capacitor. The limiting circuit is connected to the high potential power supply and the charge control circuit to limit the voltage provided to the capacitor from the high potential power supply before the charge control circuit stops providing the voltage of the high potential power supply to the capacitor.
1. A level shift circuit for converting a voltage level of an input signal to a predetermined voltage level and generating a level-shifted signal, the level shift circuit comprising:
a capacitor having a first electrode connected to a high potential power supply and a second electrode for receiving the input signal;
a charge control circuit connected to the first electrode of the capacitor for providing the voltage of the high potential power supply to the capacitor and controlling charging of the capacitor;
a first inverter for receiving the voltage of the high potential power supply and generating the level-shifted signal, wherein the first inverter includes a high potential power supply terminal connected to the first electrode of the capacitor and a low potential power supply terminal connected to the second electrode of the capacitor; and
a current limiting circuit connected to the charge control circuit for limiting the discharge current of the capacitor.
2. The level shift circuit according to claim 1 , wherein the current limiting circuit is controlled at a time different from that of the charge control circuit.
3. The level shift circuit according to claim 2 , wherein the charge control circuit includes a first PMOS transistor, the gate of which receives the level-shifted signal of the first inverter.
4. The level shift circuit according to claim 3 , wherein the current limiting circuit includes a second PMOS transistor, the gate of which receives the input signal.
5. The level shift circuit according to claim 4 , wherein the input signal has the voltage of the high potential power supply.
6. The level shift circuit according to claim 3 , further comprising:
a second inverter for generating an inverted input signal by inverting the input signal and providing the inverted input signal to the second electrode of the capacitor, wherein the second inverter includes a high potential power supply terminal for receiving the voltage of the high potential power supply and a low potential power supply terminal for receiving a voltage lower than the voltage of the high potential power supply, and wherein the current limiting circuit includes a second PMOS transistor, the gate of which receives the inverted input signal.
7. The level shift circuit according to claim 6 , wherein the input signal has the voltage of the high potential power supply.
8. The level shift circuit according to claim 3 , further comprising:
a second inverter for generating an inverted input signal by inverting the input signal and providing the inverted input signal to the second electrode of the capacitor, wherein the second inverter includes a high potential power supply terminal for receiving the voltage of the high potential power supply and a low potential power supply terminal for receiving a voltage lower than the voltage of the high potential power supply, wherein the current limiting circuit includes a second PMOS transistor and a third inverter connected to a gate of the second PMOS transistor, wherein the third inverter includes a high potential power supply terminal for receiving the voltage of the high potential power supply and a low potential power supply terminal for receiving a voltage lower than the voltage of the high potential power supply, and wherein the third inverter generates an inverted input signal by inverting the input signal and provides the inverted input signal to the gate of the second PMOS transistor.
9. The level shift circuit according to claim 8 , wherein the input signal has the voltage of the high potential power supply.
10. A level shift circuit comprising:
a capacitor;
a charge control circuit connected to the capacitor for providing a voltage of a high potential power supply to the capacitor and controlling charging of the capacitor; and
a limiting circuit connected to the high potential power supply and the charge control circuit for stopping the voltage provided to the capacitor from the high potential power supply before the charge control circuit stops providing the voltage of the high potential power supply to the capacitor,
wherein the charge control circuit includes an inverter, the low potential power supply terminal of which receives a voltage that, changes based on an input signal provided to the level shift circuit.
11. A level shift circuit comprising:
a capacitor;
a charge control circuit connected to the capacitor for providing a voltage of a high potential power supply to the capacitor and controlling charging of the capacitor; and
a limiting circuit connected to the high potential power supply and the charge control circuit for stopping the voltage provided to the capacitor from the high potential power supply before the charge control circuit stops providing the voltage of the high potential power supply to the capacitor,
wherein the charge control circuit includes an inverter which outputs a voltage changing between a first voltage level and a second voltage level and wherein the second voltage level is larger than the first voltage level and the voltage of the high potential power supply.