applikator, light sensing chip

The LM 1890 is a general purpose building block for use in visible light and infra-red applications whether they be analogue or digitally oriented. Included on a single bipolar chip are a I inear light-to-current converter, a voltage comparator biased with light-derived currents, and a voltage reference (figure 1 ). Photocurrent is produced by an on-chip photodiode that is ion-implanted to produce a shallow junction depth. The resultant spec-tral response is enhanced in the visible light range (figure 2) as compared with conven-tional silicon photodiodes.