| Gate drive optocoupler XD0129is a driver IC used for driving power MOSFET(Metal-Oxide-Semiconductor Field-Effect Transistor) or IGBT (Insulated Gate BipolarTransistor).Firstly, an overview to the component, the parameter and the action of optocouplerare given. The irradiating principle of infared light emitting diode and the workingtheory of photodiode are highlighted. The model of the photodiode is given. Secondly,internal structure of power MOSFET is analyzed in detail. Thus, a parameter model isproposed. Finally, according to the parameter model and driving principle of powerMOSFET, the optocoupler XD0129has been devised for gate driving. XD0129consistsof a gallium arsenide (AlGaAs) light emitting diode at input and a drive circuit at output.A pre-regulated circuit based on regulation principle of zener diode is designed in theReference module, which meets the operating voltage range and improves precision.The chip integrates an Under Voltage LockOut module with hysteresis, which could turnoff the chip at Under Voltage and avoid security issue at threshold.Based on a0.4μm BCD (Bipolar CMOS DMOS) process, function and electricalcharacteristics of the whole chip are simulated. The results show that the supply voltagerange is15~30V. Meanwhile, with a10resistance and a10nF capacitor in series atoutput, the maximum propagation delay, the maximum rise time and fall time are400ns,100ns and100ns, respectively. The up and down thresholds of Under Voltage Lockoutare12.65V and11.15V, respectively. The peak output current is2.0A at typicalconditions. The performance reaches the indicator. |
