High voltage generator

• US 9,960,672 B2
• Filed: 07/21/2014
• Issued: 05/01/2018
• Est. Priority Date: 08/09/2013
• Status: Active Grant

• Current Assignee: Industry-University Cooperation Foundation Hanyang University, SK Hynix Inc.
• Original Assignee: Industry-University Cooperation Foundation Hanyang University, SK Hynix Inc.
• Inventors: Kim, Young-Il, Lee, Sang-Sun, Choi, Sung-Wook
• Primary Examiner(s): Lee, III, Henry
• Application Number:
  US14/337,020
• Publication Number:
  US 20150043255A1
• Time in Patent Office: 1,380 Days
• CPC Class Codes: G11C 5/145 Applications of charge pumps; Boosted voltage circuits; Clamp circuits therefor G11C5/141 takes precedence
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode
• CPC Class Codes: H02M 1/36 Means for starting or stopping converters
• CPC Class Codes: H02M 3/07 using capacitors charged and discharged alternately by semiconductor devices with control electrode , e.g. charge pumps

Abstract

A high voltage generator includes a voltage converting device that increases a level of an input voltage and outputs an output voltage having a level higher than the level of the input voltage. The high voltage generator further includes a precharge controller that gradually increases the level of the input voltage up to a level of an external voltage based on a reference voltage and the output voltage.

Claims

1. A high voltage generator comprising:

a voltage converting device configured to output an output voltage having a level higher than a level of an input voltage; and

a precharge controller configured to increase the level of the input voltage of the voltage converting device up to a level of an external voltage to prevent breakdown of a circuit in the voltage converting device receiving the input voltage based on a reference voltage and the output voltage of the voltage converting device,

wherein the precharge controller comprises a voltage transmitting device configured to transmit the external voltage to an input node of the voltage converting device in response to a control signal, and

wherein the voltage transmitting device includes a MOS transistor having a source connected to one of a node of the external voltage and the input node of the voltage converting device, a drain connected to the other of the node of the external voltage and the input node of the voltage converting device, and a gate receiving the control signal.

2. The high voltage generator according to claim 1, wherein the precharge controller further comprises:

a reference voltage selector configured to generate a first control voltage based on a result of comparing the reference voltage and a first feedback voltage, the first feedback voltage being determined based on the output voltage;

a first controller configured to control a voltage level of the control signal based on the first control voltage and a second control voltage, the second control voltage being determined based on the input voltage; and

a second controller configured to control the voltage level of the control signal based on a result of comparing the first feedback voltage and the reference voltage.

3. The high voltage generator according to claim 2, further comprising a first voltage divider configured to generate the first feedback voltage by dividing the output voltage.

4. The high voltage generator according to claim 3, further comprising a second voltage divider configured to generate a second feedback voltage by dividing the input voltage.

5. The high voltage generator according to claim 2, wherein the first controller comprises:

a first amplifier configured to amplify a difference between the first control voltage and the second control voltage; and

a second amplifier configured to amplify an output voltage of the first amplifier.

6. The high voltage generator according to claim 5, wherein the first controller further comprises:

a third amplifier configured to buffer an output voltage of the second amplifier.

7. The high voltage generator according to claim 2, wherein the second controller comprises:

a comparator configured to compare the first feedback voltage and the reference voltage; and

a switching element configured to control the voltage level of the control signal in response to an output of the comparator.

8. The high voltage generator of claim 2, wherein the reference voltage selector comprises:

a first current source connected to a node of an internal source voltage having a level lower than the level of the external voltage;

a first switching element connected between the first current source and a ground voltage node and controlled by the reference voltage; and

a second switching element connected between the first current source and the ground voltage node and controlled by the first feedback voltage.

9. The high voltage generator of claim 8, further comprising:

a second current source connected between the node of the internal source voltage and a third switching element; and

the third switching element connected between the second current source and the ground voltage node and controlled by a second feedback voltage.

10. The high voltage generator of claim 1, wherein the voltage converting device includes a charge pumping device that has a plurality of unit pumps.

11. The high voltage generator of claim 1, wherein the MOS transistor is a PMOS transistor having a source connected to the node of the external voltage, a drain connected to the input node of the voltage converting device, and a gate receiving the control signal.

12. The high voltage generator of claim 11, wherein the precharge controller further comprises a protection diode connected to the drain of the PMOS transistor.

13. The high voltage generator of claim 11, wherein the precharge controller further comprises a first protection diode connected between the gate of the PMOS transistor and the second controller.

14. The high voltage generator of claim 13, wherein the precharge controller further comprises a second protection diode connected between the node of the external voltage and the gate of the PMOS transistor.

15. The high voltage generator of claim 14, wherein the first protection diode and the second protection diode are not turned on simultaneously.

16. The high voltage generator of claim 1, further comprising:

a discharging device configured to discharge the voltage converting device when the external voltage becomes lower than a predetermined voltage.

17. The high voltage generator of claim 16, wherein the discharging device comprises:

a discharge controller configured to output a discharge control signal based on the external voltage and the predetermined voltage; and

a discharge switching device configured to form a discharge path between the voltage converting device and a ground voltage node.

18. The high voltage generator of claim 17, wherein the discharge controller includes:

a voltage divider configured to output a discharge sensing voltage by dividing the external voltage; and

a comparator configured to compare the discharge sensing voltage and a discharge reference voltage and output the discharge control signal.

19. The high voltage generator of claim 17, wherein the voltage converting device includes a plurality of unit pumps.

20. The high voltage generator of claim 19, wherein the discharge switching device includes a plurality of MOS transistors, each of which has a gate connected to the discharge control signal, a source connected to the ground voltage node, and a drain connected to a node of each of the plurality of unit pumps.

21. The high voltage generator according to claim 1, wherein the precharge controller receives the external voltage and outputs the input voltage to the voltage converting device.