HCNR200 & HCNR201 Analog Optocouplers Broadcom HCNR200 and HCNR201 Analog Optocouplers consist of a high-performance AlGaAs LED that illuminates two closely matched photodiodes. The input photodiode monitors and stabilizes the light output of the LED. The nonlinearity and drift characteristics of the LED can be virtually eliminated. The output photodiode produces a photocurrent that is linearly related to the light output of the LED. The close matching of the photodiodes and advanced design of the package ensure the high linearity and stable gain characteristics of the optocoupler.