Overview: NCP370 Positive and Negative
Overvoltage Protection
with Internal Low RON N-MOSFETs and Reverse
Charge Control Pin http://onsemi. The NCP370 is an overvoltage, overcurrent and reverse control device. Two main modes are available by setting logic pins. First mode is Direct Mode from Wall−Adapter to the system. In this mode the system is both positive and negative over−voltage protected up to +28 V and down to −28 V. The wall adapter (or AC/DC charger) is disconnected from the system if the input voltage exceeds the overvoltage (OVLO) or undervoltage (UVLO) thresholds. At power up, the Vout turns on 30 ms after the Vin exceeds the undervoltage threshold.
The second mode (see Tables 1 & 2), called the Reverse Mode, allows an external accessory to be powered by the system battery or boost converter. Here the external accessory would be connected to the device input (bottom connector of system) and the device battery would be at the device output. In this case overcurrent protection is activated to prevent accessory faults and battery discharge. Thanks to the NCP370 using an internal NMOS, the system cost and the PCB area of the application board are minimized.
The NCP370 provides a negative going flag (FLAG) output which alerts the system that a fault has occurred.
In addition, the device has ESD−protected input (15 kV Air) when
bypassed with a 1 mF or larger capacitor.
