KR100941631B1 - High Voltage Control Circuit of Semiconductor Device - Google Patents

Abstract

The present invention relates to a high voltage control circuit of a semiconductor device. The high voltage control circuit according to the present invention inputs a first external power supply voltage and a second external power supply voltage having a level higher than that of the first external power supply voltage, and when the first and second power supplies are stabilized, an operation signal. Power-up signal generating means for generating a; High voltage detecting means for detecting a high voltage and generating a detection signal for controlling a pumping operation; An oscillator for generating a high voltage pumping period when the detection signal of the high voltage detecting means is in an enabled state; And a high voltage pumping means for setting the second external power supply voltage to a power supply voltage and controlling high voltage pumping in synchronization with a pumping period of the oscillator. Accordingly, the present invention uses the second external power supply voltage, which is relatively higher than the first external power supply voltage used in the semiconductor memory device, in the high voltage pumping circuit. Therefore, the present invention solves the problem of a large current consumption when generating a target level of the pumping voltage, a problem of requiring a large capacity element, and facilitates the efficient generation of the pumping voltage.

Semiconductor device, high voltage, external power supply voltage,

Description

HIGH VOLTAGE CONTROL CIRCUIT OF SEMICONDECTOR MEMORY DEVICE

The present invention relates to a high voltage control circuit of a semiconductor device.

In general, a DRAM is a memory device capable of writing or reading data in a memory cell including one transistor and one capacitor. The high voltage VPP is required to drive the word line of the memory cell. The high voltage is generated in the high voltage control circuit in consideration of the power supply voltage VDD and the threshold voltage Vth of the MOS transistors constituting the cell transistor. The high voltage control circuit includes an oscillation circuit and a charge pumping circuit, and the oscillation circuit operates according to an enable signal to generate an oscillation signal having a predetermined period, and the charge pumping circuit has an external voltage according to the oscillation signal. The power supply voltage VDD is pumped to generate a high voltage having a predetermined level or more.

In a memory device having a low power supply voltage VDD of about 1.8 volts, the high voltage has a potential of about 3 to 4 volts. The high voltage is higher than the power supply voltage, which is made by pumping the power voltage using a pumping circuit.

However, in recent years, the level of external power supply voltages used in semiconductor memory devices has been gradually decreasing. Therefore, as the level of the external power supply voltage used in the semiconductor device decreases, the level of the external supply voltage supplied to the VPP also decreases, which causes a serious problem of pumping efficiency (PUMPING EFFICIENCY).

The pumping efficiency refers to a ratio of a VPP current generated by the VPP pumping unit to generate a desired VPP level and a current used for the same. The lower the pumping efficiency, the more current must be consumed in order to generate the desired VPP current, which requires a device with a large capacity.

1 illustrates a problem of a high voltage control circuit that generates a conventional VPP voltage. That is, it can be confirmed that it is difficult to satisfy the VPP target voltage of 3.0 volts at 1.0 volt of the external power supply voltage VDD. Therefore, in order to generate a VPP voltage level of 3.0 volts or more with an external power supply voltage of 1.0 volts, there is a problem in that the current consumption is very large and a large capacity device is required.

Accordingly, the present invention is to solve the above problems, and provides a high voltage control circuit of a semiconductor device that can be controlled to generate a high voltage supplied to a word line using an external power supply voltage having a level higher than a general external power supply voltage. It aims to do it.

The high voltage control circuit according to the present invention for achieving the above object comprises a pumping circuit for pumping a high voltage using a second external power supply voltage of a level relatively higher than the first external power supply voltage used in the semiconductor device. It is done.

The high voltage control circuit according to another embodiment of the present invention inputs a first external power supply voltage and a second external power supply voltage having a level higher than that of the first external power supply voltage and stabilizes the first and second power supplies. Power up signal generating means for generating an operation signal; High voltage detecting means for detecting a high voltage and generating a detection signal for controlling a pumping operation; An oscillator for generating a high voltage pumping period when the detection signal of the high voltage detecting means is in an enabled state; And a high voltage pumping means for setting the second external power supply voltage to a power supply voltage and controlling high voltage pumping in synchronization with a pumping period of the oscillator.

The present invention uses a second external power supply voltage, which is relatively higher than the first external power supply voltage used in the semiconductor memory device, in the high voltage pumping circuit. Therefore, the present invention solves the problem of a large current consumption when generating a target level of the pumping voltage, a problem of requiring a large capacity element, and facilitates the efficient generation of the pumping voltage.

Hereinafter, a high voltage control circuit of a semiconductor device according to the present invention will be described in detail with reference to the accompanying drawings.

In the high voltage control circuit of the present invention, an external power supply voltage (VDD: hereinafter referred to as a first external power supply voltage) generally used in semiconductor devices and an external power supply voltage (VDD) used in systems other than the semiconductor device. A relatively higher external power supply voltage (VDDP: hereinafter referred to as a second external power supply voltage) is selectively used. In particular, the second external power supply voltage VDDP is used only for the VPP pumping unit that generates the VPP voltage, and the first external power supply voltage VDD is used for the other circuit configurations (VPP detection unit and oscillator). It is desirable to.

2 shows a high voltage control circuit diagram of a semiconductor device according to an embodiment of the present invention. 3 shows a detailed configuration diagram of the power up unit 10 shown in FIG. 2.

In the high voltage control circuit of the semiconductor device according to the present invention, a power-up signal for inputting the first and second external power supply voltages and the internal power generated by the semiconductor device and the like, when the stabilized state is reached, And a power up unit 10 for generating PWRUP.

As shown in FIG. 3, the power-up unit 10 inputs a first external power supply voltage VDD, a VDD detector 11 that detects a level, and a second external power supply voltage VDDP. It includes a VDDP detector 12 for detecting the internal power supply detector 13 for inputting the internal power supply and detecting the level. And a power up signal generator 14 for generating an enable / disable power up signal to enable normal operation when the level detected by the detectors 11, 12, 13, etc. reaches a predetermined level.

The present invention includes a reference voltage generator 20 for generating a reference voltage VREFP used for generating the VPP voltage when the power-up signal of the power-up unit 10 is enabled (low logic). The external power supply voltage used for the reference voltage generation operation in the reference voltage generator 20 preferably uses a first external power supply voltage, that is, an external power supply voltage generally used in a semiconductor device.

In addition, the present invention compares the VPP voltage fed back with the reference voltage generated in the reference voltage generator 20, and when the VPP voltage is lower than the reference voltage, VPP detector 30 for generating a detection signal so that the VPP pumping operation can be performed ). On the contrary, when the feedback voltage is higher than the reference voltage, the detection signal is fixed to fix the VPP pumping operation. The external power supply voltage used for operation in the VPP detector 30 preferably uses a first external power supply voltage, that is, an external power supply voltage generally used in a semiconductor device.

The present invention also includes an oscillator 40 to toggle the oscillator output (OSC) to be used for the VPP pumping operation when the VPP pumping operation enable signal is generated in the VPP detector 30. The external power supply voltage used for the operation of the oscillator may also use a first external power supply voltage, that is, an external power supply voltage generally used in a semiconductor device.

In addition, the present invention includes a VPP pumping unit 50 which performs a pumping operation so that the VPP voltage can be raised to a target level according to the oscillator output of the oscillator 40. The VPP pumping unit 50 uses a second external power supply voltage when the VPP voltage is generated. That is, as the semiconductor device proceeds to the low power mode, it takes too long for the VPP voltage to reach the target level using the first external power voltage, and the current consumption is too large. Therefore, in the semiconductor device generally using the first external power supply voltage, only the VPP pumping unit 50 uses the second external power supply voltage having a level higher than the first external power supply voltage.

The VPP clamping unit 60 is configured to generate a specific voltage by clamping the generated VPP voltage, and is typically supplied as an equalized driver driving voltage of a bit line. In the present invention, it is preferable to control the operation of the VPP clamping unit to be performed when the enable signal is generated in the power-up unit 10. In addition, since the VPP clamping unit substantially generates the VPPYCLP voltage by clamping the VPP voltage, it is preferable to use the external VDDP voltage. Although not shown, the VPPYCLP voltage generated by the VPPY clamping unit is supplied as an equalized driver driving voltage.

The high voltage control circuit according to the present invention having the above configuration operates as follows.

The VDD detector 11 of the power-up unit 10 detects the level of the first external power supply voltage VDD, the VDDP detector 12 detects the level of the second external power supply voltage VDDP, and detects the internal power supply detector. 13 detects the level of the internal power supply. The level value detected by the detectors is provided to a power up signal generator 14. The power-up signal generator 14 enables / disables the level detected by the detectors 11, 12, 13, etc. to reach a certain level, and enables normal operation when all levels reach a certain level. Generate a power-up signal.

5 shows a timing diagram of the power-up signal generated by the power-up signal generator 14. As shown, the level of the second external power supply voltage VPPext is relatively higher than the first external power supply voltage VDD. However, the level of the second external power supply voltage is not always higher than the first external power supply voltage. For example, when the second external power supply voltage is input later than the first external power supply voltage, a section in which the first external power supply voltage is higher than the second external power supply voltage may appear.

Therefore, in the present invention, the respective detectors 11 and 12 detect the level of the first and second external power supply voltages, and limit the normal operation of the VPP pumping operation when the level of the second external power supply voltage is not generated. do. At this time, the output signal of the power-up signal generator 14 has a disabled state at a high level.

Alternatively, when the level of the second external power supply voltage is not generated, the second external power supply voltage level may have the first external power supply voltage level VDD or the threshold voltage level VDD-Vt. Do.

The detectors 11, 12 and 13 detect the levels of the first and second external power voltages and the internal power, and control the normal operation of the VPP pumping operation when the level of each power source generates a constant level. . At this time, the output signal of the power-up signal generator 14 is enabled at a low level.

When the power-up unit 10 generates a low level enable signal, the reference voltage generator 20 generates a reference voltage to be used for generating the VPP voltage. The reference voltage generated by the reference voltage generator 20 is input to the VPP detector 30. The VPP detector 30 compares the reference voltage with the feedback VPP voltage and generates a high level enable signal when the feedback voltage is lower than the reference voltage.

The enable signal generated by the VPP detector 30 enables the operation of the oscillator 40. The oscillator 40 generates a signal having a predetermined period while the VPP detector 30 generates a high level enable signal, and outputs the signal to the VPP pumping unit 50.

The VPP pumping unit 50 performs VPP pumping while generating a constant periodic signal from the oscillator 40. At this time, the VPP pumping unit 50 uses a second external power supply voltage that is relatively higher than the first external power supply voltage. That is, the second external power supply voltage is used as a source power supply for generating a VPP pumping current.

However, it is preferable that the VPP detector 3, the oscillator 40, and the like other than the VPP pumping unit 50 use a first external power supply voltage provided according to a semiconductor device standard as a source power supply.

FIG. 4 shows that when the second external power supply voltage is used to generate the VPP voltage using the second external power supply voltage according to the embodiment of the present invention, the VPP target voltage 3.0 volts is generated without difficulty.

The above-described preferred embodiment of the present invention is disclosed for the purpose of illustration, and is applied to the case of controlling to generate a high voltage supplied to a word line using an external power supply voltage having a level higher than a general external power supply voltage. Can be. Therefore, those skilled in the art will be able to improve, change, substitute or add other embodiments within the technical spirit and scope of the present invention disclosed in the appended claims.

1 is a characteristic diagram showing a problem of a high voltage control circuit according to the prior art;

2 is a block diagram illustrating a high voltage control circuit according to an embodiment of the present invention;

3 is a detailed configuration diagram of the power up unit shown in FIG. 2;

4 is a characteristic diagram of a high voltage control circuit according to the present invention;

FIG. 5 is a timing diagram of the power up unit shown in FIG. 2. FIG.

Explanation of symbols on the main parts of the drawings

10: power-up unit 20: reference voltage generator

30; VPP Detector 40: Oscillator

50: VPP pumping part 60: VPP clamping part

Claims (10)

delete delete delete High voltage detecting means for detecting a high voltage and generating a detection signal for controlling a pumping operation; An oscillator for generating a high voltage pumping period in response to the detection signal; And A high voltage pumping means for receiving a second external power supply voltage as a power supply voltage and generating the high voltage through a pumping operation corresponding to a high voltage pumping period of the oscillator, And the high voltage detecting means or the oscillator receives a first external power supply voltage having a voltage level lower than the second external power supply voltage as a power supply voltage. The method of claim 4, wherein And said high voltage detecting means and said oscillator receive said first external power supply voltage as a power supply voltage. The method of claim 4, wherein Further comprising a power-up signal generating means for generating a power-up signal by detecting that the first external power supply voltage and the second external power supply voltage is more than a predetermined voltage level, The power up signal generating means, A first detector configured to detect a level by inputting the first external power supply voltage; A second detector configured to detect a level by using the second external power supply voltage as an input; And And a power up signal generator for generating the power up signal in response to the output signals of the first and second detectors. The method of claim 6, The power up signal generating means, A high voltage control circuit for a semiconductor device, characterized by further comprising an internal power detector for detecting a level by inputting the internal power supply. The method of claim 6, And a reference voltage generating means for generating a reference voltage in response to the power-up signal. The method of claim 8, And the high voltage detecting means compares the reference voltage with the high voltage fed back to generate the detection signal. The method of claim 8, And said reference voltage generating means receives said first external power supply voltage as a power supply voltage.

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