Predriver Level Shifter for Infrared Transmitter
Original Publication Date: 1987-May-01
Included in the Prior Art Database: 2005-Feb-01
This article describes a circuit arrangement for a predriver level shifter for a power field-effect transistor (FET). This circuit takes a logic signal from a transceiver gate array and converts the signal to low impedance 12-volt logic levels to drive a power FET which acts as a current sink to drive an infrared (IR) light-emitting diode (LED) bank. Switching the LED bank as fast as possible is important because of the receiver filtering method. The receiver, in order to filter out high frequency fluorescent bulb noise, utilizes three filters of differentiation. The output signal voltage of the receiver is a strong function of the rise time of the received signal.