Power switch structure with low RDSon and low current limit
View Patent ↗In one embodiment, a power switch device ( 33 ) includes a first MOSFET device 41 and a second MOSFET device ( 42 ). A split gate structure ( 84 ) including a first gate electrode ( 48,87 ) controls the first MOSFET device ( 41 ). A second gate electrode ( 49,92 ) controls the second MOSFET device ( 42 ). A current limit device ( 38 ) is coupled to the first gate electrode ( 48,97 ) to turn on the first MOSFET device during a current limit mode. A comparator device ( 36 ) is coupled to the second gate electrode ( 49,92 ) to turn on the second MOSFET device ( 42 ) when the power switch device ( 33 ) is no longer in current limit mode.
1. A hot swap protection device comprising:
a split gate switching device including a first MOSFET device having a first gate electrode and a second MOSFET device having a second gate electrode;
a current limit device coupled to the first gate electrode for controlling the first MOSFET device during a current limit mode of operation; and
a comparator device coupled to the first and second gate electrodes for turning on the second MOSFET device during non-current limit mode of operation.
2. The device of claim 1 wherein the split gate switching comprises:
a plurality of first gate electrodes for controlling a plurality of first MOSFET devices; and
a plurality of second gate electrodes for controlling a plurality of second MOSFET devices, wherein at least one second gate electrode is interdigitated between a pair of first gate electrodes.
3. The device of claim 1 further comprising a load device coupled to drain regions of the first and second MOSFET devices.
4. The device of claim 3 wherein the load device comprises a DC/DC converter.
5. The device of claim 1 wherein the first and second MOSFET devices are formed in one body of semiconductor material.
6. The device of claim 1 wherein the first and second MOSFET devices, the current limit device, and the comparator device are formed on one body of semiconductor material.
7. The device of claim 1 wherein the first MOSFET device forms an inrush current limit device.
8. A power switching structure comprising:
a split gate switching device including a first switch having a first control electrode and a second switch having a second control electrode;
a current limit device coupled to the first control electrode for controlling the first switch during a current limit mode of operation; and
a comparator device coupled to the second control electrode for turning on the second switch during a non-current limit mode of operation.
9. The structure of claim 8 further comprising a load device coupled to the first and second switches.
10. The structure of claim 8 wherein the first and second switches are formed in one body of semiconductor material.
11. The structure of claim 8 wherein the first and second switches, the current limit device, and the comparator device are formed on one body of semiconductor material.