A 150-MHz TIA with un-Conventional OTA Stabilization Technique via Local Active Feed-Back

To satisfy the requirements of the 5G standards the base-band of the wireless transceiver includes circuits able to process signals with hundreds of MHz of bandwidth e.g. an active-RC filter with 150 MHz cut-off frequency. An operational transconductance amplifier with a loop gain of 35 dB at 100 MHz and 1.4 GHz unity gain bandwidth was designed using an unconventional topology in which a local feedback (LFB) path is returned to the input node as opposed to the output as it is classically done. This allows using heavy current reuse (stacking) in the LFB path without large distortion and signal losses at the output node. The circuit is operated from a 1.8 V supply and consume 4 mW of power. Post-layout simulations based on a 28 nm CMOS process shows an input referred noise integrated up to 120 MHz of 88 μV and an outstanding IIP3 of more than 51 dBm across the all band. The resulting in band FoM of 187.7 [dBJ-1] greatly exceeds the state of the art.