Power supplies in flash memory devices and systems
View Patent ↗Power supplies in flash memory devices are disclosed. A first section of a flash memory device includes non-volatile memory for storing data. A second section of the flash memory device includes at least first and second pumping circuits. The first pumping circuit receives a first voltage and produces, at an output of the first pumping circuit, a second voltage at a second voltage level that is higher than the first voltage level. The second pumping circuit has an input coupled to the first pumping circuit output for cooperatively employing the first pumping circuit to pump up from a voltage greater than the first voltage to produce a third voltage at a third voltage level that is higher than the second voltage level.
1. A device comprising:
a first section including non-volatile memory for storing data; and
a second section including at least first and second pumping circuits, said second section being a peripheral circuit section,
said first pumping circuit for receiving a first voltage at a first voltage level and for producing, at an output of said first pumping circuit, a second voltage at a second voltage level that is higher than the first voltage level, said second voltage required for carrying out a first type of memory operation associated with said non-volatile memory, and
said second pumping circuit having an input coupled to the first pumping circuit output for cooperatively employing said first pumping circuit to pump up from a voltage greater than the first voltage to produce a third voltage at a third voltage level that is higher than said second voltage level, said third voltage required for carrying out a second type of memory operation associated with said non-volatile memory, and
said first pumping circuit being configured to increase voltage produced therefrom under control of at least a first oscillation signal,
said second pumping circuit being configured to increase voltage produced therefrom under control of at least a second oscillation signal different from said first oscillation signal, and
said second section further includes first and second regulator circuits, and first and second oscillators for providing said first and second oscillation signals respectively, said first regulator circuit coupled to the first pumping circuit output, said first oscillator configured to receive an outputted voltage of said first regulator circuit, said second regulator circuit coupled to an output of the second pumping circuit, and said second oscillator configured to receive an outputted voltage of said second regulator circuit.
2. The device of claim 1 wherein said non-volatile memory comprises flash memory.
3. The device of claim 2 wherein said flash memory comprises an array of memory cells.
4. The device of claim 1 wherein said second pumping circuit pumps up from one transistor threshold voltage (V tn ) less than said second voltage level.
5. The device of claim 1 wherein said first type of memory operation is a read operation and said second type of memory operation is a program operation.
6. The device of claim 1 wherein said first regulator circuit includes at least two voltage dividers and an operational amplifier.
7. A system for producing higher voltages than a first voltage at a first voltage level, the system comprising:
first charge pump circuitry including a first chain of transistors for receiving the first voltage at an end of said first chain and for producing, at an opposite end of said first chain, a second voltage at a second voltage level that is higher than the first voltage level;
second charge pump circuitry including a second chain of transistors for receiving a third voltage at a third voltage level at an end of said second chain, and said second charge pump circuitry adapted to produce, at an opposite end of said second chain, a fourth voltage at a fourth voltage level that is higher than said second voltage level;
a level shifter having an output for outputting a level-shifted voltage; and
a switch having a control terminal coupled to said output of the level shifter, said switch for controlling, based on said level-shifted voltage, whether the second voltage at an output of the first charge pump circuitry is communicated to an input of the second charge pump circuitry, and
the second voltage level being caused to increase under control of at least a first oscillation signal received by said first charge pump circuitry,
the fourth voltage level being caused to increase under control of at least a second oscillation signal, different from said first oscillation signal, and
the system further comprising first and second regulator circuits, and first and second oscillators for providing said first and second oscillation signals respectively, said first regulator circuit coupled to the output of said first pumping circuitry, said first oscillator configured to receive an outputted voltage of said first regulator circuit, said second regulator circuit coupled to an output of said second pumping circuitry, and said second oscillator configured to receive an outputted voltage of said second regulator circuit.
8. The system of claim 7 wherein said switch comprises a transistor having first and second current carrying electrodes, said first current carrying electrode in electrical communication with said opposite end of the first chain, and said second current carrying electrode in electrical communication with said end of the second chain.
9. The system of claim 7 wherein said first regulator circuit includes two voltage dividers and an operational amplifier.
10. The system of claim 7 wherein said first regulator circuit includes trimming control circuitry.
11. The system of claim 7 further comprising at least one additional pumping circuitry working in parallel with the first pumping circuitry to provide for increased current, the at least one additional pumping circuitry being at least substantially similar to the first pumping circuitry.
12. The system of claim 7 wherein at least one of the first and second charge pumping circuitries comprises a Dickson charge pump.
13. The device of claim 12 , wherein said first regulator circuit includes trimming control circuitry to facilitate regulation of a variable program voltage.
14. A method of producing voltages in a device having a first section including non-volatile memory for storing data, and also having a second section that includes i) at least first and second pumping circuits, ii) first and second regulator circuits, and iii) first and second oscillators, and the method comprising:
supplying, within the device, a first voltage at a first voltage level to the first pumping circuit;
producing, at an output of the first pumping circuit, a second voltage at a second voltage level that is higher than the first voltage level, said second voltage required for carrying out a first type of memory operation associated with the non-volatile memory;
producing, at an output of the second pumping circuit, a third voltage by cooperatively employing the first pumping circuit to pump up from a voltage greater than the first voltage, said third voltage at a third voltage level that is higher than said second voltage level, said third voltage required for carrying out a second type of memory operation associated with the non-volatile memory;
providing, from the first oscillator, an at least one oscillation signal to the first pumping circuit, the second voltage level increasing under control of said at least one oscillation signal;
providing, from the second oscillator, an at least another oscillation signal to the second pumping circuit, said at least another oscillation signal different than said at least one oscillation signal, and the third voltage level increasing under control of said at least another oscillation signal;
receiving, at an input of the first oscillator, a control voltage outputted from the first regulator; and
receiving, at an input of the second oscillator, a control voltage outputted from the second regulator, and
said first type of memory operation comprises a program operation.
15. The method of claim 14 wherein the non-volatile memory is flash memory.
16. The method of claim 15 wherein said second type of memory operation comprises an erase operation.
17. The method of claim 16 further comprising carrying out said erase operation.
18. The method of claim 15 wherein said first voltage is V DD .
19. The method as claimed in claim 15 wherein there is at least one transistor threshold voltage (V tn ) difference between said second voltage and said voltage greater than the first voltage.
20. The method of claim 14 further comprising carrying out said program operation.
21. A device comprising:
a first section including non-volatile memory for storing data; and
a second section including at least first and second pumping circuits, said second section being a peripheral circuit section,
said first pumping circuit for receiving a first voltage at a first voltage level and for producing, at an output of said first pumping circuit, a second voltage at a second voltage level that is higher than the first voltage level, said second voltage required for carrying out a first type of memory operation associated with said non-volatile memory, and
said second pumping circuit having an input coupled to the first pumping circuit output for cooperatively employing said first pumping circuit to pump up from a voltage greater than the first voltage to produce a third voltage at a third voltage level that is higher than said second voltage level,
said first pumping circuit being configured to increase voltage produced therefrom under control of at least a first oscillation signal,
said second pumping circuit being configured to increase voltage produced therefrom under control of at least a second oscillation signal different from said first oscillation signal, and
said second section further including at least one additional pumping circuit working in parallel with the first pumping circuit to provide for increased current, the at least one additional pumping circuit being at least substantially similar to the first pumping circuit, and
said second section further including first and second regulator circuits, and first and second oscillators for providing said first and second oscillation signals respectively, said first regulator circuit coupled to the first pumping circuit output, said first oscillator configured to received an outputted voltage of said first regulator circuit, said second regulator circuit coupled to an output of the second pumping circuit, and said second oscillator configured to receive an outputted voltage of said second regulator circuit.
22. A device comprising:
a first section including non-volatile memory for storing data; and
a second section including at least first and second pumping circuits, said second section being a peripheral circuit section,
said first pumping circuit for receiving a first voltage at a first voltage level and for producing, at an output of said first pumping circuit, a second voltage at a second voltage level that is higher than the first voltage level, said second voltage required for carrying out a first type of memory operation associated with said non-volatile memory,
said second pumping circuit having an input coupled to the first pumping circuit output for cooperatively employing said first pumping circuit to pump up from a voltage greater than the first voltage to produce a third voltage at a third voltage level that is higher than said second voltage level, and
said first pumping circuit being configured to increase voltage produced therefrom under control of at least a first oscillation signal,
said second pumping circuit being configured to increase voltage produced therefrom under control of at least a second oscillation signal different from said first oscillation signal,
at least one of the first and second pumping circuits comprises a Dickson charge pump, and
said second section further includes first and second regulator circuits, and first and second oscillators for providing said first and second oscillation signals respectively, said first regulator circuit coupled to the first pumping circuit output, said first oscillator configured to receive an outputted voltage of said first regulator circuit, said second regulator circuit coupled to an output of the second pumping circuit, and said second oscillator configured to receive an outputted voltage of said second regulator circuit.