Radiation Hardened CMOS Programmable Bias Generator for Space Applications at 180nm

This work presents a two-channel 8-bit programmable bias generator (PBG) that provides output voltage ranges from 0.5V to 2.1V in 256 steps and drives
$\bm{100\Omega}$
resistive in parallel with a 100pF capacitive load. The design is radiation hard and achieves constant functionality over the −55°C to 125°C temperature range. A Radhard voltage reference, class AB folded cascode opamp, and an R-2R digital-to-analog converter (RDAC) is designed in the PBG with a common Centroid layout. After fabrication, the device was tested, and characterization results show that the PBG has a maximum, 0.18 LSB differential nonlinearity and -0.53 integral nonlinearity. After functional testing, radiation testing was done up to 300krad on the device, and device functionality was constant. The total die size, including input-output pads of the fabricated radiation-hardened PBG device, is
$3\ \mathbf{mm }\times 3$
mm, and power consumption is less than 5 mW. This device is implemented using
$\bm{0.18}\upmu \mathbf{m}$
CMOS technology.