Internal setting of primary coil voltage, internal setting of coil current limit, logic level compatible input, drive current quasi-proportional to collector current, single flag coil current, low voltage clamp thermal shutdown High voltage power integrated circuits with vertical current power Darlington and logic level compatible driver circuits. When the input is on, the enable pin allows the switch to be blocked externally. The built-in coil current limiting and collector voltage clamping protection circuit can be used as an intelligent, high-voltage, high-current interface to use an advanced electronic ignition system. If the input signal from the microcontroller happens to be kept high, the device prevents overheating by forcing a smooth reduction in collector current (low voltage clamping characteristic) and does not create unwanted sparks.

The working principle of VB325SP is mainly as a high-voltage power switch device driven by logic level input, which is directly connected to the high-energy electronic ignition coil. The input VIN of the VB325SP is provided by a low power signal generated by an external controller, which determines the dwell time and ignition point. During VIN high (≥4V) periods, the VB325SP increases the current in the coil to the desired internally set current level. Once this level is reached, the coil current remains constant until the ignition point, corresponding to a VIN transition from high to low (typical). 1.9V threshold). During the turn-off period of the coil current, the primary voltage HVC is limited to an internal set value Vcl, typically 380V. The transition from saturation to desaturation, the current limiting phase of the coil, must have the ability to withstand overvoltage. The maximum amount of overshoot allowed. Feedback When the collector current exceeds 4.5A, the feedback signal goes high and remains constant until the input voltage is turned off. Overvoltage VB325SP can withstand the following transients from the battery line: -100V/2msec (Ri=10Ω) +100V/0.2msec (Ri=10Ω) +50V/400msec (Ri=4.2Ω, VIN=3V)

Typical application diagram

Inductive load switching time