LX1802

Voltage potential......................................................................................... 0.0V to +20.0V
ESD Voltage................................................................................................................. 2kV
Storage Temperature Range(TSTOR)................................................................10°C to 55°C
Storage humidity...............................................................................................10% to 90%

The MSC-LX1802 is the IC2 "Plug" for the MED427A-1 module. The "Plug" chip has peak rectifier, level shifter, and switch. This full wave peak rectifier converts the peak to peak AC input waveform to a DC level. The charge builds up on both terminals of the storage capacitor to step up the DC level during a full wave input signal. The charge dissipates via a resistor when the AC input signal stops. The level shifter LX1802 is a source follower transistor with a resistive load. The input connects to the peak rectifier output and the output connects to IGBT_G. If the input voltage is below threshold, the output (IGBT_G) equals IGBT_E voltage. If the input voltage exceeds the threshold voltage of the transistor, the output steps up to the bootstrap voltage Vhi+IGBT_E at the IGBT_G output. The switch supplements the discharge of the capacitor in the peak rectifier when the AC input signal stops. The switch remains open when there is an AC signal since a virtual ground forms at LX1802's input and prevents a channel from forming in the active device. The opposite occurs when the AC signal stops and the input builds a potential greater than a threshold voltage.