Reducing latency when activating a power supply unit

A system for reducing latency when activating a power supply unit (PSU) among a plurality of PSUs in a power supply system, the system comprising:

• a supply bus comprising a voltage rail, the supply bus and voltage rail operatively connected to each PSU within the power supply system;
• a plurality of power input feeds, wherein each of the plurality of power input feeds provides input voltage to one of the plurality of PSUs;
• and
• the plurality of PSUs, wherein each of the plurality of PSUs comprises memory for storing instructions executed by a central processing unit (CPU), a charging module comprising a resistor and a switch, and a switching regulator comprising an output capacitor, wherein the PSU is configured to:
• receive input power from one of the plurality of power input feeds;
• receive, from the supply bus, a first controlled signal designating the status of the PSU as standby;
• disable, using the CPU and in response to the first controlled signal, the switching regulator;
• receive, from the voltage rail, charge flowing through the resistor of the charging module to maintain a charge of the output capacitor of the switching regulator;
• receive, from the supply bus, a second controlled signal designating the status of the PSU as active;
• enable, using the CPU and in response to the second controlled signal, the switching regulator;
• charge the output capacitor using the PSU;
• and
• output voltage from the PSU through the charging module to the voltage rail.

A power supply unit (PSU) comprising:

• a charging module comprising a resistor and a switch and operatively connected to a supply bus;
• a switching regulator comprising an output capacitor and operatively connected to the charging module;
• an input stage comprising a plurality of components configured to:
• receive input power from a power input feed;
• receive, from the supply bus through the resistor of the charging module, a first controlled signal designating a status of the PSU as standby;
• disable, in response to the first controlled signal, the switching regulator;
• receive, from a voltage rail of the supply bus, charge flowing through the resistor of the charging module to maintain a charge of the output capacitor;
• receive, from the supply bus, a second controlled signal designating the status of the PSU as active;
• enable, in response to the second controlled signal, the switching regulator;
• in response to enabling the switching regulator:
• output a voltage from the input stage through the switch of the charging module to the voltage rail;
• and
• charge the output capacitor using the voltage output from the input stage.