A 1-V 7th-Order SC Low-Pass Filter for 77-GHz Automotive Radar in 28-nm FD-SOI CMOS

Abstract

This paper presents a switched capacitor low-pass filter in a 28-nm fully depleted silicon on insulator CMOS technology for 77-GHz automotive radar applications. It is operated at a power supply as low as 1 V and guarantees 5-dB in-band voltage gain while providing out-of-band attenuation higher than 36 dB and a programmable passband up to 30 MHz. A double sampling technique is adopted, which allows high operating frequency to be achieved while saving power. Moreover, low-voltage biasing and common-mode feedback circuits are exploited to guarantee an almost rail-to-rail output voltage swing. The proposed filter provides an output 1-dB compression point as high as 8.7 dBm with a power consumption of 9 mW. To the authors’ knowledge, this is the first SC-based implementation of a low pass filter for automotive radar applications.

CMOS IC Solutions for the 77 GHz Radar Sensor in Automotive Applications

“…The filter operates with a sampling frequency, fS, up to 200 MHz and exploits a double sampling technique to reduce the current consumption. The filter provides a passband up to 20 MHz along with an out-of-band attenuation of around 40 dB at 2 MHz from the passband boundary [40]. The receiver core die is shown in Figure 7.…”

A 2.5-Vpp PVT-insensitive high dynamic range output stage using bulk voltages adjustment

“…This improvement makes sense in a high-resolution ADC [7,8]. What's more, the high output range facilitates high-quality signals in applications like SC filters [9,10], modulators [11,12,13,14], and et al [15,16,17]. However, as the supply voltage scales down, achieving a high output range becomes difficult [18,19,20].…”