Systems and methods for voltage level shifting in a device
View Patent ↗Level shifters are disclosed for high performance sub-micron IC designs. One embodiment is a level shifting device that comprises a first input circuit that toggles a first internal signal between a logical zero of a first voltage range and a logical one of a second voltage range based on an input data signal and an output data signal, and a second input circuit that toggles a second internal signal between a logical zero of the second voltage range and a logical one of the first voltage range based on the input data signal and the output data signal. An output circuit of the device toggles the output data signal between a logical zero of the second voltage range and a logical one of the second voltage range based on the first internal signal, the second internal signal, and a compliment of the input data signal.
1. A level shifting device for translating a logic level input data signal having a first voltage range to a logic level output data signal having a second voltage range, the level shifting device comprising:
a first input circuit configured to toggle, based on the input data signal and the output data signal, a first internal signal between a logical zero of the first voltage range and a logical one of the second voltage range;
a second input circuit configured to toggle, based on the input data signal and the output data signal, a second internal signal between a logical zero of the second voltage range and a logical one of the first voltage range; and
an output circuit configured to toggle, based on the first internal signal, the second internal signal, and a compliment of the input data signal, the output data signal between a logical zero of the second voltage range and a logical one of the second voltage range.
2. The level shifting device of claim 1 wherein:
the first voltage range comprises a first supply having a first logical one reference voltage and a first logical zero reference voltage;
the second voltage range comprises a second supply having a second logical one reference voltage and a second logical zero reference voltage;
the first input circuit is coupled to the second logical one reference voltage and to the first logical zero reference voltage;
the second input circuit is coupled to the first logical one reference voltage and the second logical zero reference voltage; and
the output circuit is coupled to the second logical one reference voltage and the second logical zero reference voltage.
3. The level shifting device of claim 2 wherein the first input circuit comprises:
a first field-effect transistor (FET) having a source terminal coupled to the first logical zero reference voltage, a gate terminal coupled to the input data signal, and a drain terminal coupled to the first internal signal;
a second FET having a source terminal, a gate terminal coupled to the input data signal, and a drain terminal coupled to the first internal signal; and
a third FET having a source terminal coupled to the second logical one reference voltage, a gate terminal coupled to the output data signal, and a drain terminal coupled to the source terminal of the second FET.
4. The level shifting device of claim 3 wherein:
the first FET comprises an N-channel FET; and
the second FET and the third FET comprise P-channel FETs.
5. The level shifting device of claim 3 wherein the first input circuit further comprises:
a fourth FET having a source terminal coupled to the first internal signal, a gate terminal coupled to the compliment of the input data signal, and a drain terminal coupled to the second logical one reference voltage.
6. The level shifting device of claim 5 wherein:
the fourth FET comprises an N-channel FET.
7. The level shifting device of claim 2 wherein the second input circuit comprises:
a first field-effect transistor (FET) having a source terminal coupled to the second logical zero reference voltage, a gate terminal coupled to the output data signal, and a drain terminal;
a second FET having a source terminal coupled to the drain terminal of the first FET, a gate terminal coupled to the input data signal, and a drain terminal coupled to the second internal signal; and
a third FET having a source terminal coupled to the first logical one reference voltage, a gate terminal coupled to the input data signal, and a drain terminal coupled to the second internal signal.
8. The level shifting device of claim 7 wherein:
the first FET and the second FET comprise N-channel FETs; and
the third FET comprises a P-channel FET.
9. The level shifting device of claim 7 wherein the second input circuit further comprises:
a fourth FET having a source terminal coupled to the second logical zero reference voltage, a gate terminal coupled to the compliment of the input data signal, and a drain coupled to the second internal signal.
10. The level shifting device of claim 9 wherein:
the fourth FET comprises a P-channel FET.
11. The level shifting device of claim 2 wherein the output circuit comprises:
a first field effect transistor (FET) having a source terminal coupled to the second logical zero reference voltage, a gate terminal coupled to the second internal signal, and a drain terminal;
a second FET having a source terminal coupled to the drain terminal of the first FET, a gate terminal coupled to the compliment of the input data signal, and a drain terminal coupled to the output data signal;
a third FET having a source terminal, a gate terminal coupled to the compliment of the input data signal, and a drain terminal coupled to the output data signal;
a fourth FET having a source terminal coupled to the second logical one reference voltage, a gate terminal coupled to the first internal signal, and a drain terminal coupled to the source terminal of the third FET.
12. The level shifting device of claim 11 wherein:
the first FET and the second FET comprise N-channel FETs; and
the third FET and the fourth FET comprise P-channel FETs.
13. The level shifting device of claim 11 wherein the output circuit further comprises:
a fifth FET having a source terminal coupled to the second logical zero reference voltage, a gate terminal coupled to the input data signal, and a drain coupled to the output data signal; and
a sixth FET having a source terminal coupled to the output data signal, a gate terminal coupled to the input data signal, and a drain coupled to the second logical one reference voltage.
14. The level shifting device of claim 13 wherein:
the fifth FET comprises a P-channel FET; and
the sixth FET comprises an N-channel FET.
15. A level shifting device for translating a logic level input data signal having a first voltage range to a logic level output data signal having a second voltage range, the level shifting device comprising:
a first power supply that provides the first voltage range and has a first logical one reference voltage and a first logical zero reference voltage; and
a second power supply that provides the second voltage range and has a second logical one reference voltage and a second logical zero reference voltage;
an input circuit configured to toggle, based on the input data signal and the output data signal, a first internal signal between the first logical zero reference voltage and the second logical one reference voltage, and to toggle, based on the input data signal and the output data signal, a second internal signal between the second logical zero reference voltage and the first logical one reference voltage; and
an output circuit configured to toggle, based on the first internal signal, the second internal signal, and a compliment of the input data signal, the output data signal between the second logical zero reference voltage and the second logical one reference voltage.
16. The level shifting device of claim 15 wherein the input circuit comprises:
a first field-effect transistor (FET) having a source terminal coupled to the first logical zero reference voltage, a gate terminal coupled to the input data signal, and a drain terminal coupled to the first internal signal;
a second FET having a source terminal, a gate terminal coupled to the input data signal, and a drain terminal coupled to the first internal signal;
a third FET having a source terminal coupled to the second logical one reference voltage, a gate terminal coupled to the output data signal, and a drain terminal coupled to the source terminal of the second FET;
a fourth FET having a source terminal coupled to the second logical zero reference voltage, a gate terminal coupled to the output data signal, and a drain terminal;
a fifth FET having a source terminal coupled to the drain terminal of the fourth FET, a gate terminal coupled to the input data signal, and a drain terminal coupled to the second internal signal; and
a sixth FET having a source terminal coupled to the first logical one reference voltage, a gate terminal coupled to the input data signal, and a drain terminal coupled to the second internal signal.
17. The level shifting device of claim 16 wherein the input circuit further comprises:
a seventh FET having a source terminal coupled to the first internal signal, a gate terminal coupled to the compliment of the input data signal, and a drain terminal coupled to the second logical one reference voltage; and
an eighth FET having a source terminal coupled to the second logical zero reference voltage, a gate terminal coupled to the compliment of the input data signal, and a drain coupled to the second internal signal.
18. The level shifting device of claim 15 wherein the output circuit comprises:
a first field effect transistor (FET) having a source terminal coupled to the second logical zero reference voltage, a gate terminal coupled to the second internal signal, and a drain terminal;
a second FET having a source terminal coupled to the drain terminal of the first FET, a gate terminal coupled to the compliment of the input data signal, and a drain terminal coupled to the output data signal;
a third FET having a source terminal, a gate terminal coupled to the compliment of the input data signal, and a drain terminal coupled to the output data signal; and
a fourth FET having a source terminal coupled to the second logical one reference voltage, a gate terminal coupled to the first internal signal, and a drain terminal coupled to the source terminal of the third FET.
19. The level shifting device of claim 18 wherein the output circuit further comprises:
a fifth FET having a source terminal coupled to the second logical zero reference voltage, a gate terminal coupled to the input data signal, and a drain coupled to the output data signal; and
a sixth FET having a source terminal coupled to the output data signal, a gate terminal coupled to the input data signal, and a drain coupled to the second logical one reference voltage.
20. A level shifting device for translating a logic level input data signal that transitions between a first logical one reference voltage and a first logical zero reference voltage to a logic level output data signal that transitions between a second logical one reference voltage and a second logical zero reference voltage, the level shifting device comprising:
a first field-effect transistor (FET) having a source terminal applied to the first logical zero reference voltage, a gate terminal applied to the input data signal, and a drain terminal applied to a first internal signal;
a second FET having a source terminal, a gate terminal applied to the input data signal, and a drain terminal applied to the first internal signal;
a third FET having a source terminal applied to the second logical one reference voltage, a gate terminal applied to the output data signal, and a drain terminal applied to the source terminal of the second FET;
a fourth FET having a source terminal applied to the second logical zero reference voltage, a gate terminal applied to the output data signal, and a drain terminal;
a fifth FET having a source terminal applied to the drain terminal of the fourth FET, a gate terminal applied to the input data signal, and a drain terminal applied to a second internal signal;
a sixth FET having a source terminal applied to the first logical one reference voltage, a gate terminal applied to the input data signal, and a drain terminal applied to the second internal signal;
a seventh FET having a source terminal applied to the second logical zero reference voltage, a gate terminal applied to the second internal signal, and a drain terminal;
an eighth FET having a source terminal applied to the drain terminal of the seventh FET, a gate terminal applied to a compliment of the input data signal, and a drain terminal applied to the output data signal;
a ninth FET having a source terminal, a gate terminal applied to the compliment of the input data signal, and a drain terminal applied to the output data signal; and
a tenth FET having a source terminal applied to the second logical one reference voltage, a gate terminal applied to the first internal signal, and a drain terminal applied to the source terminal of the ninth FET.