Design of a Programmable Gain Amplifier (PGA) for Bluetooth Low Energy (BLE) in 0.13 um CMOS

Abstract

Programmable Gain Amplifiers (PGA's) are circuits capable of conveniently changing their gain to address various levels of amplification. Knowing this, the topology proposed in this work takes a source degenerated first stage, a common-source with resistive load second stage, and a gm boosting circuit interface to realize a PGA that has low power consumption and low area. The design developed was able to achieve a maximum power dissipation of 103.1 uW, a minimum bandwidth of 5.59 MHz, a maximum noise of 32.01 nV/sqrt(Hz), and a gain range of 2.31 - 19.84 dB. Each differential output of the circuit is loaded with 700 fF, which is the estimated load for the hypothetical following block, the Analog-to-Digital Converter (ADC). Furthermore, the supply voltage of the circuit is 1 V and the design was undertaken on Global Foundrie's 130 nm technology. The phase margin of the core circuit is no greater than 100.3˚  and no less than 49˚  . The circuit which design is described in this work is intended to be within the receiver (RX) sub-domain of a Bluetooth Low-Energy (BLE) system, which finds applications on the IoT and healthcare industries, for instance.