High-side driver has fault protection. (design ideas).(Brief Article)

HIGH-SIDE DRIVERS FIND common use in driving grounded solenoid coils and other loads. Short-circuit protection for such drivers is essential for avoiding damage from wiring faults and other causes. Polymer fuses are generally too slow, and discrete current-limiting circuits are large and cumbersome. The circuit in Figure 1 uses a small, low-dropout linear regulator as a high-side switch and provides inherent current limiting and thermal shutdown. The regulator comes in an SO-8 package. The zener diode provides transient protection, and the output capacitor ensures stability of the