Heimdall IR Receivers Vishay Semiconductors Heimdall IR Receivers are miniaturized SMD IR receiver modules for infrared remote control systems. The two PIN diodes and a preamplifier are assembled on a lead frame and the epoxy package contains an IR filter. The demodulated output signals from the transmitters can be directly connected to a microprocessor for decoding. Vishay Semiconductors Heimdall IR Receivers are optimized to suppress almost all spurious pulses from Wi-Fi / CFL sources. These IR receivers offer improved immunity against HF, RF, and optical noises.