An integrated MEMS inertial sensing device can include a MEMS inertial sensor with a drive loop configuration overlying a CMOS IC substrate. The CMOS IC substrate can include an AGC loop circuit coupled to the MEMS inertial sensor. The AGC loop acts in a way such that generated desired signal amplitude out of the drive signal maintains MEMS resonator velocity at a desired frequency and amplitude. A benefit of the AGC loop is that the charge pump of the HV driver inherently includes a ‘time constant’ for charging up of its output voltage. This incorporates the Low pass functionality in to the AGC loop without requiring additional circuitry.