Non-volatile semiconductor memory having multiple external power supplies
View Patent ↗A memory device includes core memory such as flash memory for storing data. The memory device includes a first power input to receive a first voltage used to power the flash memory. Additionally, the memory device includes a second power input to receive a second voltage. The memory device includes power management circuitry configured to receive the second voltage and derive one or more internal voltages. The power management circuitry supplies or conveys the internal voltages to the flash memory. The different internal voltages generated by the power management circuitry (e.g., voltage converter circuit) and supplied to the core memory enable operations such as read/program/erase with respect to cells in the core memory.
1. A memory device comprising:
flash memory for storing data;
a first power input to receive a first voltage used to power the flash memory;
a second power input to receive a second voltage;
power management circuitry for receiving the second voltage and deriving at least first and second internal voltages conveyed to the flash memory, the power management circuitry including:
i) first charge pump circuitry to convert the second voltage to the first internal voltage that is higher than the second voltage, and
ii) second charge pump circuitry to convert the second voltage to the second internal voltage that is higher than the first internal voltage; and
wherein the second voltage is greater than the first voltage.
2. A memory device as in claim 1 , wherein at least one of the internal voltages conveyed to the flash memory enables at least a selected one of:
i) programming of cells in the flash memory,
ii) erasing of cells in the flash memory, and
iii) reading data from cells in the flash memory.
3. A memory device as in claim 1 , wherein the first internal voltage and the second internal voltage support data access operations with respect to the flash memory.
4. A memory device as in claim 1 , wherein the first internal voltage and the second internal voltage are used to support different types of data access operations with respect to the flash memory.
5. A memory device as in claim 1 , wherein the power management circuitry receives the first voltage, the memory device further comprising:
detector circuitry to monitor the second voltage and, when the second voltage is below a threshold value, generate a signal notifying the power management circuitry to derive at least one of the internal voltages based on the first voltage rather than the second voltage.
6. A memory device as in claim 5 , wherein the detector circuitry is configured to monitor the second voltage and, when the second voltage is above the threshold value, generate a signal notifying the power management circuitry to derive at least one of the internal voltages based on the second voltage rather than the first voltage.
7. A memory device as in claim 1 further comprising:
a substrate;
the power management circuitry and the flash memory residing on the substrate;
the substrate including:
i) a first conductive path to convey the first voltage received on the first power input to the flash memory, and
ii) a second conductive path to convey the second voltage received on the second power input to the power management circuitry.
8. A memory device as in claim 7 , wherein the first power input is a first pin of the memory device for receiving the first voltage from a first power source external to the memory device; and
wherein the second power input is a second pin of the memory device for receiving the second voltage from a second power source external to the memory device.
9. A memory device as in claim 1 , wherein the first voltage is Vcc and the second voltage is Vpp.
10. The memory device as in claim 1 , wherein a magnitude of the second voltage is substantially greater than a magnitude of the first voltage.
11. The memory device as in claim 10 , wherein the magnitude of the second voltage is at least double the magnitude of the first voltage.
12. The memory device as in claim 11 , wherein the first internal voltage is greater in magnitude than the magnitude of the second voltage and wherein the second internal voltage is greater in magnitude than the magnitude of the second voltage.
13. The memory device as in claim 1 , wherein a magnitude of the first voltage is less than 3.3 volts and a magnitude of the second voltage is greater than about 5 volts.
14. The memory device as in claim 1 further comprising:
a first conductive path to convey the first internal voltage to the flash memory; and
a second conductive path to convey the second internal voltage to the flash memory.
15. The memory device as in claim 1 , wherein conversion of the second voltage into the first internal voltage and the second internal voltage provides higher power conversion efficiency than would conversion of the first voltage into the first internal voltage and the second internal voltage.
16. The memory device as in claim 1 , wherein the power management circuitry includes a multi-stage charge pump to receive the second voltage and produce the second internal voltage, the multi-stage charge pump having fewer stages to convert the second voltage into the second internal voltage than would be needed to convert the first voltage into the second internal voltage.
17. The memory device as in claim 1 , wherein the first voltage and the second voltage are generated from different power sources.
18. The memory device as in claim 1 further comprising:
input/output logic providing access to the data stored in the flash memory, the input/output logic powered by the first voltage.
19. The memory device as in claim 1 , wherein the power management circuitry receives the first voltage to power at least a portion of circuitry in the power management circuitry other than the first charge pump circuitry and the second charge pump circuitry.
20. The memory device as in claim 1 further comprising:
switch circuitry to select between use of the first voltage and use of the second voltage for generating the first internal voltage and the second internal voltage.
21. The memory device as in claim 1 further comprising:
a configuration register specifying which of the first voltage or the second voltage from which to generate the first internal voltage and the second internal voltage.
22. A memory device as in claim 1 , wherein the flash memory is NAND flash memory.
23. A memory device as in claim 1 , wherein the flash memory is NOR flash memory.
24. A memory device as in claim 1 further comprising:
an oscillator to generate a master clock signal;
a first driver circuit configured to receive the master clock signal and generate, based on the master clock signal, a signal to control operation of the first charge pump circuitry; and
a second driver circuit configured to receive the master clock signal and generate, based on the master clock signal, a signal to control operation of the second charge pump circuitry.
25. A memory device as in claim 1 further comprising:
reference generator circuitry to generate a first reference and a second reference;
first regulator circuitry to receive the first reference and the first internal voltage, the first regulator circuitry generating an output indicating whether the first internal voltage is within regulation; and
second regulator circuit circuitry to receive the second reference and the second internal voltage, the second regulator circuitry generating an output indicating whether the second internal voltage is within regulation.
26. A memory device as in claim 1 , wherein the flash memory includes a data cell for storing bit information, the data cell comprising a substrate contact, a gate contact, a source contact, and a drain contact.
27. A memory device as in claim 26 , wherein the flash memory erases the data cell by applying: a ground potential to the gate contact, an open circuit to the drain contact, an open circuit to the source contact, and the first internal voltage to the substrate contact.
28. A memory device as in claim 26 , wherein the flash memory programs the data cell by applying the second internal voltage to the gate contact, and by applying a ground potential to each of the drain contact, the source contact, and the substrate contact.
29. A memory device as in claim 26 , wherein the flash memory reads from the data cell by applying the first internal voltage to the drain contact, and by applying a ground potential to each of the drain contact, the source contact, and the substrate contact.
30. A memory device as in claim 26 , wherein the flash memory reads from the data cell by applying the second internal voltage to the drain contact, and by applying a ground potential to each of the drain contact, the source contact, and the substrate contact.
31. A memory system comprising:
a first voltage;
a second voltage, the second voltage being greater than the first voltage; and
a memory device, the memory device including:
i) flash memory powered by the first voltage, and
ii) a power management circuitry to receive and convert the second voltage into a first internal voltage and a second internal voltage used by the respective flash memory;
the power management circuitry including:
i) a first charge pump to convert the second voltage into the first internal voltage, the first internal voltage being greater than the second voltage, and
ii) a second charge pump to convert the second voltage into the second internal voltage, the second internal voltage being greater than the first internal voltage.
32. A memory system as in claim 31 , wherein the flash memory utilizes the first internal voltage and the second internal voltage produced by the power management circuitry to manage data stored in the flash memory.
33. A memory system as in claim 32 , wherein the memory device is one of multiple memory devices in the memory system, each of the memory devices configured to receive the first voltage and the second voltage, each of the memory devices including: i) a respective flash memory powered by the first voltage, and ii) respective power management circuitry to convert the second voltage to a set of higher internal voltages used by the respective flash memory to manage data therein.
34. A memory system as in claim 31 further comprising:
a circuit substrate;
the memory device residing on the circuit substrate;
the circuit substrate including:
i) a first conductive path to convey the first voltage from a first power source to a first power input pin of the memory device, and
ii) a second conductive path to convey the second voltage from a second power source to a second power input pin of the memory device.
35. A memory system as in claim 34 , wherein the first power input pin delivers the first voltage to the flash memory of the memory device; and
wherein the second power input pin delivers the second voltage to the power management circuitry of the memory device.
36. A memory system as in claim 31 ,
wherein the first internal voltage and the second internal voltage generated by the power management circuitry enables at least a selected one of:
i) programming of cells in the flash memory,
ii) erasing of cells in the flash memory, and
iii) reading data from cells in the flash memory.
37. A memory system as in claim 31 , wherein the first voltage is Vpp and the second voltage is Vcc.
38. A memory system as in claim 31 , wherein the memory device is one of multiple memory devices in the memory system, the memory system including a first conductive path and a second conductive path, the first conductive path conveying the first voltage to each of the multiple memory devices, the second conductive path conveying the second voltage to each of the multiple memory devices.
39. A memory system as in claim 38 further comprising:
a power converter configured to convert an input voltage into the first voltage and the second voltage.
40. A memory system as in claim 38 , wherein the memory system is a thumb drive device that plugs into a computer.
41. A memory device comprising:
flash memory for storing data;
a first power input to receive a first voltage used to power the flash memory;
a second power input to receive a second voltage;
power management circuitry for receiving the first voltage and the second voltage, the power management circuitry deriving at least one internal voltage conveyed to the flash memory; and
detector circuitry to monitor the second voltage and, when the second voltage is below a threshold value, generate a signal notifying the power management circuitry to derive the at least one internal voltage based on the first voltage rather than the second voltage.
42. A memory device as in claim 41 , wherein the at least one internal voltage conveyed to the flash memory enables at least a selected one of:
i) programming of cells in the flash memory,
ii) erasing of cells in the flash memory, and
iii) reading data from cells in the flash memory.
43. A memory device as in claim 41 , wherein the power management circuitry includes charge pump circuitry to convert the second voltage to an internal voltage that is greater than the second voltage, the internal voltage being supplied to the flash memory and supporting data access operations with respect to the flash memory.
44. A memory device as in claim 43 , wherein the second voltage is greater than the first voltage.
45. A memory device as in claim 41 , wherein the at least one internal voltage is used to support different data access operations with respect to the flash memory.
46. A memory device as in claim 41 , wherein the first voltage used to power the flash memory is less than the second voltage.
47. A memory device as in claim 41 , wherein the detector circuitry is configured to monitor the second voltage and, when the second voltage is above the threshold value, generate a signal notifying the power management circuitry to derive the at least one internal voltage based on the second voltage rather than the first voltage.
48. A memory device as in claim 41 further comprising:
a substrate;
the power management circuitry and the flash memory residing on the substrate;
the substrate including:
i) a first conductive path to convey the first voltage received on the first power input to the flash memory, and
ii) a second conductive path to convey the second voltage received on the second power input to the power management circuitry.
49. A memory device as in claim 48 , wherein the first power input is a first pin of the memory device for receiving the first voltage from a first power source external to the memory device; and
wherein the second power input is a second pin of the memory device for receiving the second voltage from a second power source external to the memory device.
50. A memory device as in claim 41 , wherein the first voltage is Vcc and the second voltage is Vpp.
51. A memory device comprising:
memory for storing data;
a first power input to receive a first voltage to power the memory;
a second power input to receive a second voltage, the second voltage being greater than the first voltage; and
power management circuitry for receiving the second voltage and deriving at least a first internal voltage and a second internal voltage to control accesses to the data in the memory, the power management circuitry including:
i) first circuitry to convert the second voltage to the first internal voltage, and
ii) second circuitry to convert the second voltage to the second internal voltage.