Voltage discharge circuit having divided discharge current
AssigneeLattice Semiconductor Corporation
InventorsRobert Gary Pollachek, Loren Mclaury, Fabiano Fontana
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Abstract
In one embodiment, a voltage discharge (VD) system has a slow VD subsystem that provides two concurrent discharge current paths to at least begin to discharge both positive and negative voltages: a first path from the positive-voltage node to ground and a second path from the positive-voltage node to the negative-voltage node. In addition to this relatively slow VD subsystem, the VD system can also have a conventional fast VD subsystem that is turned on after the slow VD subsystem has reduced the positive and negative voltages to some degree (e.g., half of each charge removed). Such a VD system can eliminate dangerous overshoot conditions, even when control-signal skew is present.
Claims18
In an integrated circuit having a reference-voltage ground (e.g., Vss), a method for discharging a positive node (e.g., array_well) having a positive voltage (e.g., Vpp) relative to ground and a negative node (e.g., negative_pump) having a negative voltage (e.g., Vneg) relative to ground, the method comprising:
- (a) establishing concurrent first and second discharge paths, wherein:
- the first discharge path (e.g., mirror0) is between ground and a first node of the negative and positive nodes;
- and
- the second discharge path (e.g., mirror1, divider, follower) is between the negative and positive nodes;
- and
- (b) dividing discharge current from the first node between the first discharge path and the second discharge path.
An integrated circuit having a reference-voltage ground (e.g., Vss) and comprising a voltage discharge (VD) system for discharging a positive node (e.g., array_well) having a positive voltage (e.g., Vpp) relative to ground and a negative node (e.g., negative_pump) having a negative voltage (e.g., Vneg) relative to ground, the VD system comprising first and second discharge paths, wherein:
- the first discharge path (e.g., mirror0) is between ground and a first node of the negative and positive nodes;
- and
- the second discharge path (e.g., mirror1, divider, follower) is between the negative and positive nodes, such that the first and second discharge paths concurrently divide discharge current from the first node between the first discharge path and the second discharge path.
Dependencies are inferred from the claim text.