What is power sequencing?
The power sequence is the sequence in which the power is applied and shut down, and includes specifications of the time intervals between steps in the sequence. In other words, the power sequence is a procedure whereby the controlling side must fix the status of the controlled side.
What is power supply sequencer?
A power supply cycle has three operating steps: sequence-up, monitoring and sequence-down. Figure 2 shows these phases for a typical system. During up-sequencing, each power supply must wait its turn, and then power up to the correct voltage in a designated amount of time.
What is the voltage of power good signal?
The power good signal is a +5 volts signal that is generated by a switching power supply when the supply has stabilized its output voltages and passed all its internal self-tests.
What’s the best way to control power sequencing?
One of the most common is to control power-sequencing of circuits with many different rails. For instance, you may have a Supply B that is not supposed to turn on until Supply A is on, and stable.
How is a sequencing function implemented in a power supply?
A typical sequencing function can be implemented by using the ADM1184 to monitor the output voltage of one regulator and provide a logic-high signal to the enable pin of the next regulator once the output voltage being monitored reaches a certain level.
What can you do with a power good signal?
It’s generally a logic level signal and what you do with it is up to you. For example you can use it for power sequencing, you can feed it into a GPIO on a processor for monitoring or hook it up to a red LED that will light up if power isn’t good.
Why is the PG pin not active during startup?
It takes a (short) while to charge up the coil during startup. in that time voltage on output rises slowly, PG will not be active until the voltage meets the specifications. That is the main reason for the PG pin to be there (that and indication of overload).