Level shifter circuit
A level shifting circuit that includes a level shifter and a circuit stage. The circuit stage includes a pair of diodes circuits. The circuit stage includes a first output node and a second output node. The first output node is coupled via a current path to a first output of the level shifter and the second output node is coupled to via a current path to a second output of the level shifter. One of the diodes is coupled to the first output node and a power supply terminal. The other diode is coupled to the second output node and the power supply terminal.
1. A circuit comprising:
a level shifter including an input to receive a signal to be level shifted, the level shifter including a first power supply terminal and a second power supply terminal, the level shifter including a first output node and a second output node;
a first stage comprising:
a third power supply terminal;
a fourth power supply terminal;
a first node;
a second node;
a first transistor the first transistor including a first current terminal coupled to the third power supply terminal, a second current terminal coupled to the first node, and control terminal connected to the second node;
a second transistor, the second transistor including a first current terminal coupled to the third power supply terminal, a second current terminal coupled to the second node, and a control terminal connected to the first node;
a first diode circuit located in a current path between the fourth power supply terminal and the first node with a first terminal of the first diode circuit coupled to the fourth power supply terminal and a second terminal of the first diode circuit coupled to the first node; and
a second diode circuit located in a current path between the fourth power supply terminal and the second node with a first terminal of the second diode circuit coupled to the fourth power supply terminal and a second terminal of the second diode circuit coupled to the second node;
a first current path from the first output node of the level shifter to the first node, the first current path including a third transistor and a fourth transistor coupled in series, wherein the third transistor includes a control terminal coupled to the second power supply terminal and the fourth transistor includes a control terminal coupled to the fourth power supply terminal; and
a second current path from the second output node of the level shifter to the second node, the second current path including a fifth transistor and a sixth transistor coupled in series, wherein the fifth transistor includes a control terminal coupled to the second power supply terminal and the sixth transistor includes a control terminal coupled to the fourth power supply terminal.
2. The circuit of claim 1 wherein the second node provides a level shifted signal of a signal received at the input during operation.
3. The circuit of claim 1 wherein:
the first terminal of the first diode circuit is characterized as an anode and the second terminal of the first diode circuit is characterized as a cathode; and
the first terminal of the second diode circuit is characterized as an anode and the second terminal of the second diode circuit is characterized as a cathode.
4. The circuit of claim 1 wherein the first diode circuit is implemented with a first diode configured transistor and the second diode circuit is implemented with a second diode configured transistor.
5. The circuit of claim 4 wherein the first diode configured transistor is characterized as an NFET transistor and the second diode configured transistor is characterized an NFET transistor.
6. The circuit of claim 1 wherein the level shifter includes a second input to receive a complementary signal to a signal received at the input, wherein a signal provided at the first node is a level shifted signal of a signal received at the second input during operation.
7. The circuit of claim 1 wherein the first and second transistors are each characterized as a PFET transistor.
8. The circuit of claim 1 wherein:
the level shifter includes a seventh transistor, an eighth transistor, a ninth transistor, and a tenth transistor,
the seventh transistor includes first current terminal coupled to the first power supply terminal, a second current terminal coupled to the first output node, and a control terminal coupled to the input;
the eighth transistor includes first current terminal coupled to the first power supply terminal, a second current terminal coupled to the second output node, and a control terminal coupled to a second input to receive a signal complementary of the signal received by the input;
the ninth transistor includes a first current terminal coupled to the second power supply terminal, a second current terminal coupled to the first output node, and a control terminal coupled to the second output node; and
the tenth transistor includes a first current terminal coupled to the second power supply terminal, a second current terminal coupled to the second output node, and a control terminal coupled to the first output node.
9. The circuit of claim 1 wherein the third and fifth transistors are each characterized as NFET transistors and the fourth and sixth transistors are each characterized as PFET transistors.
10. The circuit of claim 1 wherein a voltage range of each of the first node and the second node is between a voltage of the third power supply terminal and a second voltage, where the second voltage is within a threshold voltage of a voltage of the fourth power supply terminal.
11. The circuit of claim 1 wherein a voltage range of the first output node and the second output node is between a voltage of the first power supply terminal and a voltage of the second power supply terminal.
12. The circuit of claim 1 wherein the second node is coupled to a control terminal of a PFET of a multiplexer circuit.
13. The circuit of claim 1 further comprising:
a second level shifter including an input coupled to the second node, the second level shifter including an output.
14. The circuit of claim 13 wherein the output of the second level shifter is coupled to a control terminal of an NFET transistor of an inverter.
15. The circuit of claim 13 wherein:
a voltage range of the second node is between a voltage of the third power supply terminal and a second voltage where the second voltage is within a threshold voltage of a voltage of the fourth power supply terminal; and
a voltage range of the output of the second level shifter is between the voltage of the third power supply and the voltage of the fourth power supply terminal.
16. The circuit of claim 13 wherein the first node is coupled to a second input of the second level shifter.
17. The circuit of claim 1 wherein the second power supply terminal and the fourth power supply terminal are coupled together to supply the same voltage.
18. The circuit of claim 1 wherein the second power supply terminal and the fourth power supply terminal are configured to provide different voltages.
19. A level shifting circuit comprising:
a first transistor including a first current terminal connected to a first power supply terminal, a second current terminal connected to a first node, and a control terminal configured to receive a first input signal;
a second transistor including a first current terminal connected to the first power supply terminal, a second current terminal connected to a second node, and a control terminal configured to receive a second input signal that is complementary to the first input signal;
a third transistor including a first current terminal connected to the first node, a second current terminal connected to a second power supply terminal and a control terminal connected to the second node;
a fourth transistor including a first current terminal connected to the second node, a second current terminal connected to the second power supply terminal and a control terminal connected to the first node;
a fifth transistor including a first current terminal connected to the first node, a second current terminal, and a control terminal connected to the second power supply terminal;
a sixth transistor including a first current terminal connected to the second node, a second current terminal, and a control terminal connected to the second power supply terminal;
a seventh transistor including a first current terminal connected to the second current terminal of the fifth transistor, a second current terminal connected to a third node, and a control terminal connected to a third power supply terminal;
an eighth transistor including a first current terminal connected to the second current terminal of the sixth transistor, a second current terminal connected to a fourth node, and a control terminal connected to the third power supply terminal;
a ninth transistor including a first current terminal connected to a fourth power supply terminal, a second current terminal connected to the third node, and a control terminal connected to the fourth node;
a tenth transistor including a first current terminal connected to the fourth power supply terminal, a second current terminal connected to the fourth node, and a control terminal connected to the third node;
an eleventh transistor including a first current terminal connected to the third node, a second current terminal connected to the third power supply terminal, and a control terminal connected to the third power supply terminal; and
a twelfth transistor including a first current terminal connected to the fourth node, a second current terminal connected to the third power supply terminal, and a control terminal connected to the third power supply terminal.