Automatic recovery electronic fuse with soft start function

Automatic recovery electronic fuse with soft start function

The circuit is shown in the attached figure. TPS2014 is an N-channel MOSFET power distribution switch launched by Texas Instruments, USA. It uses an 8-pin DIP dual in-line package, and the functions of each pin are as follows: ① Pin GND (ground terminal); ②, ③ Pin IN (voltage input terminal), the input voltage range is VIN=0.3~7V; ④ Pin EN (logic enable control), the switch is turned on when EN=0; ⑤ Pin DC (overcurrent logic output terminal), DC=0 in the fault state; ⑥, ⑦, ⑧ Pin OUT (voltage output terminal), VOUT=0.3-(VIN+0.3)V.

Close the start switch SB, add the low-level control signal to the ④ pin, and control the rise and fall time of the power switch through the internal circuit. In order to delay the transient process of the output voltage, limit the surge current during the switching time to the minimum, and the transient time is determined by the capacity of C2. When the load RL is overcurrent or short-circuited, the chip automatically switches to the constant current output mode, and the output of the ⑤ pin jumps to a low level, and the fault indicator LED2 lights up. The chip will not resume normal function until the fault is eliminated. When using, the ② and ③ pins should be connected in parallel to minimize the chip voltage drop and power consumption.