| 摘要 |
An improved power interface device suitable for managing power for a PCMCIA card is disclosed which includes internal charge pumps, to gradually turn on the device's internal N-channel MOSFETs, and a first discharge circuit for gradually turning off the N-channel MOSFETs. The first discharge circuit includes an MOS capacitor that incrementally discharges the gates of the N-channel MOSFETs such that the turn-off speed of each N-channel MOSFET is controlled by the ratio of the capacitances of the capacitor and the MOSFET's gate. A second discharge circuit includes a capacitor and is used to gradually turn on the interface device's internal P-channel MOSFET by incrementally charging its gate. The turn-on speed of the P-channel MOSFET is controlled by the ratio of the capacitances of this capacitor and the MOSFET's gate. In another embodiment, diode clamps are provided to protect the interface device's N-channel MOSFETs against time dependent breakdown. The diode clamps are formed within the substrate housing the device's internal charge pumps, thereby saving valuable die area.
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