Analog Devices Inc. ADPD4200 Sensor Front End operates as a complete photometric sensor front end, stimulating up to four Light Emitting Diodes (LEDs). This Sensor Front End also measures the return signal on up to four separate current inputs. The ADPD4200 Sensor Front End is equipped with twelve-time slots that enable twelve separate measurements per sampling period. This sensor includes a control circuitry with flexible LED signaling and synchronous detection. The ADPD4200 Sensor Front End uses a 1.8V analog core and 1.8V or 3.3V compatible digital input/output (I/O). This sensor features dual-channel processing with simultaneous sampling, on-chip digital filtering, 400mA total LED peak drive current, and 512-byte FIFO size. The ADPD4200 Sensor Front End includes multiple applications in wearable health and fitness monitors, industrial monitoring, and home patient monitoring devices.