Electric power conversion systems – Current conversion – With voltage multiplication means
Reexamination Certificate
1999-12-02
2001-02-20
Wong, Peter S. (Department: 2838)
Electric power conversion systems
Current conversion
With voltage multiplication means
C363S059000, C307S110000
Reexamination Certificate
active
06191962
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is related to a step-up power supply circuit for producing a higher step-up voltage than a preselected power supply voltage, and also to a semiconductor integrated circuit device equipped with the step-up power supply circuit.
2.
Conventionally, in an electronic appliance with employment of a dry cell and an on-vehicle battery, having relatively low output voltages, a step-up power supply circuit is provided. The step-up power supply circuit produces a step-up voltage in response to the output voltage of the above-described power supply. This step-up voltage is used as an operating power supply voltage in this electronic appliance.
FIG. 11
represents an example of an electronic appliance arranged by employing the above-described conventional step-up power supply circuit
1
and a semiconductor integrated circuit device
2
having a plurality of amplifiers AM
0
to AM
3
. In this drawing, the step-up power supply circuit
1
is equipped with a rectangular wave generating circuit
4
and a step-up circuit
5
, which are operated under a power supply voltage Vcc outputted from a power supply
3
such as a dry cell and an on-vehicle battery.
The rectangular wave generating circuit
4
is constituted by an astable multivibrator and the like, which outputs such a rectangular wave Sc. The amplitude of this rectangular wave is rapidly inverted in a predetermined time period. The step-up circuit
5
is arranged by a voltage doubler rectifying circuit equipped with a rectifying diode and a capacitor. The step-up circuit
5
ON/OFF-controls the rectifying diode in synchronism with the rectangular wave Sc to charge the capacitor, so that a step-up voltage HVcc higher than the power supply voltage Vcc is produced.
This step-up voltage HVcc is applied to the semiconductor integrated circuit device
2
, and since the amplifiers AM
0
to AM
3
are operated while using the step-up voltage HVcc as the operating power supply voltage, these amplifiers AM
0
to AM
3
amplify signals entered into input terminals IN
0
to IN
3
to thereby output the amplified signals to the respective output terminals Q
0
to Q
3
.
On the other hand, in the above-described conventional step-up power supply circuit
1
, since the rectifying diode contained in the step-up circuit
5
is ON/OFF-controlled based upon the rectangular wave Sc containing the radio frequency (high frequency) components, the RF (radio frequency) switching noise is produced from the rectifying diode. There is a problem that this RF switching noise is entered into the amplifiers AM
0
to AM
3
provided in the semiconductor integrated circuit device
2
and then is mixed with the respective amplified signals derived from the output terminals Q
0
to Q
3
.
Also, there is another problem that in order to prevent adverse influences caused by the switching noise, a total number of externally provided components such as the noise absorbing capacitors, resistors, or coils is increased.
Also, in order to avoid the above-explained adverse influence caused by the switching noise given to the semiconductor integrated circuit device
2
, since the step-up power supply circuit
1
and the semiconductor integrated circuit device
2
are separately arranged from each other, a total number of electronic component would be increased. Furthermore, it is practically difficult to realize a high-performance electronic appliance within a limited volume in a high density. Also, it is practically difficult to realize such a semiconductor integrated circuit device containing the conventional step-up power supply circuit
1
, and also the amplifiers AM
0
to AM
3
which are susceptible to the noise adverse influence.
When the step-up voltage HVcc produced by the step-up circuit
5
is used as the operating power supply voltage to drive the amplifiers AM
0
to AM
3
, there is such an effect that the dynamic range can be improved. However, in order to actually achieve this effect, the amplification factors of the amplifiers AM
0
to AM
3
is required to be increased in response to the increase in the stepped-up operating power supply voltage.
That is to say, in such a case that both the amplitudes of the input signals entered into the amplifiers AM
0
to AM
3
, and the amplification factors of the amplifiers AM
0
to AM
3
are the same as those of each other irrespective to high/low operating power supply voltages of the amplifiers AM
0
to AM
3
, the output signals outputted from the amplifiers AM
0
to AM
3
are equal to each other irrespective of the high/low operating power supply voltages. As a result, in order to actually achieve the effect of the wide dynamic range, the amplification factors of the amplifiers AM
0
to AM
3
are required to be increased in response to increasing of the operating power supply voltage.
However, conventionally, while the variable resistors and the like are connected to the amplification factor adjusting terminals provided with the amplifiers AM
0
to AM
3
, the amplification factors are adjusted by manually adjusting the values of the variable resistors. As a result, there are problems that the adjusting work becomes cumbersome, and furthermore, the externally provided electronic components such as the above-explained variable resistors are required, which induces an increase of total numbers of such electronic components.
SUMMARY OF THE INVENTION
The present invention has been made to solve the conventional problems, and therefore, has an object to provide a step-up power supply circuit capable of suppressing an occurrence of noise, and also to provide a semiconductor integrated circuit device capable of automatically self-adjusting an optimum operating condition in response to a stepped-up voltage.
To achieve the above-described object, a step-up power supply circuit, according to an aspect of the present invention, is featured by comprising a first rectifying element and a first capacitive element series-connected between a first contact point and a second contact point; a second rectifying element connected between a joint point between the first rectifying element and the first capacitive element, and a third contact point; a second capacitive element connected between the third contact point and a fourth contact point; and drive means for outputting a signal having a waveform whose amplitude is not rapidly changed, but becomes constant every predetermined time period; wherein: plural sets containing the first/second rectifying elements and the first/second capacitive elements are cascade-connected to each other in a plurality of stages; the first contact point of a post-staged set is connected to the third contact point of a pre-staged set; the second contact point is commonly connected; a predetermined power supply voltage is applied to the first contact point of a topmost-staged set; the signal of the drive means is supplied to the second contact point of the topmost-staged set; and the fourth contact point is set to a lower voltage than the predetermined voltage.
In accordance with the step-up power supply circuit having this arrangement, when the signal derived from the drive means is applied to the second terminal, biases of the first and second rectifying elements of each set are alternately inverted in response to a change in amplitudes of this signal, so that the ON/OFF switching operation is carried out. The first and second capacitive elements of each set are charged by this ON/OFF switching operation, a step-up voltage substantially two times higher than the power supply voltage is produced across the third terminal of the topmost-staged set. Also, voltages substantially 3 times, and 4 times higher than the power supply voltage are produced across the third terminals of the sets subsequent to the second stage, namely the step-up voltages substantially integer times higher than the power supply voltage are produced across the third terminal.
In this case, since the signal of the drive means is such a signal having a waveform whose amplitude b
Inohana Haruyuki
Ozawa Akio
Yoshizumi Norio
Pioneer Corporation
Sughrue Mion Zinn Macpeak & Seas, PLLC
Vu Bao Q.
Wong Peter S.
LandOfFree
Step-up power supply circuit and semiconductor integrated... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Step-up power supply circuit and semiconductor integrated..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Step-up power supply circuit and semiconductor integrated... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2571608