The super-slow spectrum (3S, 0mHz » 40mHz) be the important feature of neurotransmitters in slow synaptic transmissions for brain cognition function. 3S analysis focuses on the near infrared (940nm) otopoints (mapping prefrontal cortex and temporal lobe) data in high validity for such as lie detection. The goal is to design 3S analysis micro system based on digital ADC and FPGA. My ideas are in voltage-controlled oscillator (not gate chain or Schmitt trigger) for digital ADC and in state machine and embedded RAM with Cyclone EP1C6 FPGA. The db4 order-10 low frequency wavelet algorithm was hardened into this FPGA. The validity results touched 87% for lie test and 80% for smile test. This work may lay a prelimi- nary foundation for neurotransmitter measurement SoC.