| 摘要 |
<p>A circuit, (54) comprising a plurality of switches (S1, S2, S3, S4 and S5) coupled together in a charge pump arrangement (56). A first switch (S1) is driven by a first driver (X1), and a second switch (S2) is driven by a second driver (X2). The first and second switches (S1 and S2) are connected to the input voltage terminal (Vin). The charge pump arrangement (56) is adapted to provide a boot voltage (Vboot) and a drive voltage (Vdry) for a switch mode power supply. At least the first driver (X1) is powered by a voltage higher than the input voltage (Vin). The higher voltage maybe obtained from a voltage (V3) at a node between an additional switch (S6) and an additional capacitor (C3). Alternatively, the higher voltage may be obtained from the boot voltage (Vboot). Powering the driver (X1) with the higher voltage allows the lateral semiconductor area of the charge pump circuit (56) to be reduced, by using NMOS FETs for at least one switch. The invention is particularly useful for applications such as DSPs and mixed signal or analog circuits. <IMAGE></p> |
