Low Power AFE Circuit Supporting IR Array Sensor for Human Detection

We are developing technology for camera systems to monitor humans using an intermittent-sensing scheme. In this system, to reduce power consumption, a CMOS image sensor is powered on and captures optical images when humans are detected using a low-power IR array sensor. A low-power analog front end (AFE) circuit that reads the small output voltage of an IR array sensor is required to create the system. Therefore, we examined the circuit for the IR array sensor using methods of a dual-slope integrating analog-to-digital converter (ADC). Consequently, a power reduction of approximately 83% compared with existing IR array sensor devices is expected. Another expected achievement is a battery life of about 12 months, which would be 4.7 times longer than that of the previous system using an existing IR array sensor device for the whole system.