Semiconductor device and radio communication device
First Claim
1. A semiconductor device having a negative bias generation circuit including:
- an oscillation circuit that can switch an output thereof between high frequency oscillation and low frequency oscillation;
a down converter circuit that includes a first capacitor and stores charges in the first capacitor by an output of the oscillation circuit;
a charge capacity switching circuit; and
a second capacitor that is coupled in parallel to the first capacitor and can be disconnected electrically by the charge capacity switching circuit,wherein the oscillation circuit performs high frequency oscillation when the power of the semiconductor device is turned on,wherein the charge capacity switching circuit electrically disconnects the second capacitor from the first capacitor, andwherein the down converter circuit stores charges in the first capacitor.
2 Assignments
0 Petitions
Accused Products
Abstract
To provide a fast charge means for a capacitor in a negative bias generation circuit. A capacitor is present in a down converter in a negative bias generation circuit. In order to perform fast charge, the capacitance of the capacitor is reduced and a necessary amount of charge is minimized. On the other hand, an external capacitance provided separately from the capacitor in the down converter is coupled directly to a power supply voltage and charged. After the capacitor in the down converter is charged, the external capacitance and the capacitor in the down converter are coupled in parallel. Due to this, it is made possible to aim at both the increase in charge speed and the improvement of resistance to ripple noise.
4 Citations
10 Claims
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1. A semiconductor device having a negative bias generation circuit including:
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an oscillation circuit that can switch an output thereof between high frequency oscillation and low frequency oscillation; a down converter circuit that includes a first capacitor and stores charges in the first capacitor by an output of the oscillation circuit; a charge capacity switching circuit; and a second capacitor that is coupled in parallel to the first capacitor and can be disconnected electrically by the charge capacity switching circuit, wherein the oscillation circuit performs high frequency oscillation when the power of the semiconductor device is turned on, wherein the charge capacity switching circuit electrically disconnects the second capacitor from the first capacitor, and wherein the down converter circuit stores charges in the first capacitor. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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Specification