| 摘要 |
<p>A charge pump (10) has a chain of diode connected MOS transistors (12a-12i) to generate a high voltage output (Vout). Each of the serially connected MOS transistor (12a-12i) has a capacitor (20a-20i) with one end connected to the input of one of the transistors. A ring oscillating circuit receives an enable signal (ENABLE) and generates a plurality of oscillating signals. Each oscillating signal has the same frequency and is supplied to the second end of a capacitor (20a-20i). Between each capacitor (20a-20i) the ring oscillating circuit has an inverter (22a-22i) which inverts the supplied oscillating signal. Thus, immediately adjacent capacitors are provided with an inverse oscillating signal. In this manner, the charge pump (10) can be operated at a high frequency, drawing smoother current from the power supply, with greater capacitive loading distributed unto each stage of the oscillator. Finally, breakdown prevention needs only be applied to the anode of the last diode (12i).</p> |
