What is the application mode of hot plug controller

System Apr 22 16


Hot plug controllers are usually used in high availability systems such as servers, network switches, and other forms of communication infrastructure. This kind of system usually needs to replace the faulty circuit board or module in the charged state, and the system still operates normally. This process is called hot plug.

 

One use of the hot plug controller is to solve the output end protection problem of the switching DC boost circuit by using the overcurrent and short-circuit protection functions of the hot plug protection circuit.

 

Hot plug controller is a part of power management integrated circuit (IC). Hot plug refers to hot plug. Hot plug function allows users to take out and replace damaged power supply or cards and other components without shutting down the system and cutting off the power supply, thus improving the system's ability of timely recovery, expansibility and flexibility to disasters. If there is no hot plug controller, the module at the load side will have a surge current impact on the power supply when it is plugged in and out, affecting the stability of voltage and the reliability of power supply.

 

This problem can be solved by the hot plug controller, which can reasonably control the surge current and ensure the safe power on interval. After power on, the hot plug controller can continuously monitor the power supply current to avoid short circuit and overcurrent during normal operation.

 

The booster circuit of the hot plug control chip is equipped with output overcurrent and short circuit protection. When the remote terminal CTL is grounded, the power supply enters the standby mode and the output is zero. The hot plug controller includes an n-channel MOSFET serving as a main switch for power control, a detection resistor for measuring current, and a hot plug controller.

 

The hot plug controller is used to realize a loop for controlling the on current of the MOSFET, which includes a current detection comparator. The current detection comparator is used to monitor the voltage drop on the external detection resistor. When the current flowing through the detection resistor generates a voltage of more than 50 MV, it will cause the comparator to indicate overcurrent and turn off the MOSFET Tps2491 has a soft start function, in which the overcurrent reference voltage rises linearly rather than suddenly, which makes the load current change in a similar manner.

 

Another module of the hot plug controller is a timer, which limits the adjustment time of the current in the case of overcurrent. The selected MOSFET can withstand a certain power within a specified maximum time. MOSFET manufacturers use figure 3 to mark this range, or secure work area (SOA).