JAJSMS4F August 2021 – March 2024 TPS7H2211-SEP , TPS7H2211-SP
PRODUCTION DATA
The EN pin controls the state of the eFuse. Bringing EN high turns on the switch and bringing EN low turns off the switch. In a cold sparing application, only one of the switches is to be enabled at a given time. This EN signal can be controlled from external circuitry. For example, a microcontroller or FPGA may interface to the eFuses through two GPIO pins. The TPS7H2211 is compatible with a variety of logic levels such as 1.1-V logic.
When the primary 12-V rail is to be used, EN of the primary eFuse is set high while the EN of the secondary eFuse remains low. If there is an issue with the primary rail, the secondary rail can instead be used. To make this change, first deassert the EN pin of the primary eFuse. Then assert the EN pin of the secondary eFuse. If both pins are enabled at the same time, reverse current flow in one of the eFuses may result. While there is internal reverse current protection circuitry in the eFuses, it is simple to avoid this problem through proper EN sequencing.