A 5s-time-constant temperature-stable integrator for a tuneable PID controller in LOC applications

In this paper, we present a novel, ultra-long-time-constant analogue integrator for a PID controller in Lab-on-Chip (LOC) applications. A time constant of up to 5 seconds is achievable using a capacitance of only 18pF by exploiting transconductance reduction techniques involving current splitting and gm-attenuated OTA. Additionally, this architecture provides the ability to digitally tune the time constant from 200ms to 5s with 4-bit programmability. The design achieves a temperature dependance of 1.2% over the range from 0°C to 100°C with micropower consumption.