Photodiode Detector (CB1588E )

This circuit, suggested by Philips Components (1980), uses a fast voltage comparator and requires a symmetrical 5-volt power supply, which can excite TTL loads. As we can see, the outputs are complementary (flip-flops). The input resistors are selected according to the characteristics of the photodiode. R2 must have the approximate resistance of the photodiode near the trigger point.