Micro-Conductivity Rapid Detection Research of Electrophoresis Chip Based on Orthogonal Vector Lock-In Amplifier on FPGA

A capacitively coupled contactless conductivity detection (C4D) method of capillary electrophoresis microchip based on orthogonal vector lock-in amplifier on FPGA is presented. The digital orthogonal vector lock-in amplifier is configured by assembling LPM MULT, ALTMULT ADD, Low-pass Filter and other IP core. The orthogonal driving signals are generated by custom DDS IP core based on DSP Builder software, the embedded CPU, NIOS II, achieves the flexible control of detection system. The simulation results show that it can effectively weaken noise interference. Simultaneously, it can provide a novel design method for the miniaturization, integration and control of biochip system.