Cecil J. Aswell

A monolithic light-to-frequency converter with a scalable sensor array

A single-chip CMOS light to frequency converter provides light intensity measurements with an absolute accuracy of 5% and a selectable full scale sensitivity of either 1, 10 or 100 mW/ cm/sup 2/. The device incorporates a new switched-capacitor charge-metering current-to-frequency converter with an integral bandgap reference and exhibits a measured linearity error of 0.2% for a full scale frequency of 0.5 MHz and 1% for 1 MHz. A pin-programmable divider is included on the chip so that the output can be scaled for applications that require a lower frequency. An output enable is provided so that multiple units may share the same controller input line.<<ETX>>