US 11,705,900 B2
Protection circuitry
Andrew Buist, Edinburgh (GB); Mark McCloy-Stevens, Edinburgh (GB); Dave Smith, Edinburgh (GB); Gordon Russell, Dunfermline (GB); and Huy Binh Le, Edinburgh (GB)
Assigned to Cirrus Logic, Inc., Austin, TX (US)
Filed by Cirrus Logic International Semiconductor Ltd., Edinburgh (GB)
Filed on Jan. 27, 2021, as Appl. No. 17/159,786.
Claims priority of provisional application 62/968,248, filed on Jan. 31, 2020.
Prior Publication US 2021/0242865 A1, Aug. 5, 2021
Int. Cl. H03K 17/0814 (2006.01); H02H 3/18 (2006.01)
CPC H03K 17/08142 (2013.01) [H02H 3/18 (2013.01)] 22 Claims
OG exemplary drawing
 
1. Back-power prevention circuitry for preventing a back power condition in which current flows from a load into a power supply, the circuitry comprising:
an output stage comprising:
an input node configured to be coupled to the power supply; and
an output node configured to be coupled to the load; and
one or more control nodes for controlling a conduction path between the input node and the output node; and
protection circuitry coupled to the one or more control nodes, the protection circuitry configured to control the one or more control nodes to break the conduction path between the input node and the output node to prevent back current flow from the load to the power supply in response to a load voltage at the output node exceeding a supply voltage at the input node, wherein the protection circuitry comprises:
an active protection circuit configured to break the conduction path when the supply voltage exceeds an operational threshold of the active protection circuit; and
a passive protection circuit configured to break the conduction path when the supply voltage is below the operational threshold of the active protection circuit.