September 19, 2008. Most AC-DC power supplies and DC-DC converters have internal current-limiting circuits to protect the power device, and to some degree its load. The majority of over-current-protections include an automatic recovery feature. In practice, the current limit feature typically starts operating when the output current exceeds it The current sense signal is an essential part of a current-mode switch mode power supply design; it is used to regulate the output and also provides overcurrent protection. Figure 1 shows the current sensing circuit for an LTC3855 synchronous switching mode step-down power supply. The LTC3855 is a current-mode control device with cycle-by-cycle I am building a power supply with LM723 and my intention is to have 0-30V and a range of 0-5A variable. I am regulating voltage normally, however for current limiting, if I want to regulate small current amounts like 10mA, 100mA I need a shunt resistor with high value, which is not viable for 5A, since with LM723 I need a 0.67V voltage drop to limit current. \$\begingroup\$ yup, 1 additional note: Foldback current protection is much more important for a linear supply than it is for a switching supply such as those you listed. Linear supplies increase their power dissipation as the difference between Vin and Vout increases. Because of this, when the current limit is hit and voltage begins to drop, power dissipation increases even if the current is A current limiting circuit aids in power supplies by ensuring overall protection where there may be an overload or short circuits. Generally, you will find current limiters fitted in electronic components to prevent future damages during power supply. They are among the standard features needed in regulating power supplies Integrated Circuits Six countermeasures to limit startup surge current of SMPS. The inrush current of the switching power supply refers to the peak current flowing into the power supply equipment at the instant the power is turned on as shown in the below figure. Since the input filter capacitor of the charger quickly charges, the peak current is much larger than 3lxST.

power supply with current limit