US 12,218,652 B2
Autonomous power supply switch
Hamzeh Nassar, Graz (AT)
Assigned to Renesas Design Austria GmbH, Graz (AT)
Appl. No. 18/712,107
Filed by Renesas Design Austria GmbH, Graz (AT)
PCT Filed Nov. 23, 2022, PCT No. PCT/EP2022/083040
§ 371(c)(1), (2) Date May 21, 2024,
PCT Pub. No. WO2023/104525, PCT Pub. Date Jun. 15, 2023.
Claims priority of application No. 21212828 (EP), filed on Dec. 7, 2021.
Prior Publication US 2024/0333274 A1, Oct. 3, 2024
Int. Cl. H03K 17/00 (2006.01); H03K 17/693 (2006.01)
CPC H03K 17/005 (2013.01) [H03K 17/693 (2013.01)] 7 Claims
OG exemplary drawing
 
1. An autonomous power supply switch with a main supply input and a backup supply input and a supply output to which a power consumer may be connected to supply the power consumer with power provided at the main supply input and to switch to the backup supply input, if the power provided at the main supply input is below a switch threshold, wherein the switch comprises:
a first switch transistor (S1) of the PMOS type connected between the main supply input and the supply output with its source and bulk connected to the supply output and with a gate of the first switch transistor connected to a first steering point of the switch;
a second switch transistor (S2) of the PMOS type connected between the backup supply input and the supply output with its source and bulk connected to the supply output and with a gate of the second switch transistor connected to a second steering point of the switch;
an inverter or Schmitt trigger with its input connected to the second steering point and its output connected to the first steering point and its power supply connected to the backup supply input of the switch; and
an ohmic resistor (R) connected between the main supply input and the second steering point of the switch to protect the second switch transistor (S2) and the inverter of the switch against voltage spikes.