commit | b7ef3b51c0550fd42386191dcb9175e2d05a5a98 | [log] [tgz] |
---|---|---|
author | yrrapt <yrrapt@gmail.com> | Wed Feb 03 14:23:27 2021 +0100 |
committer | yrrapt <yrrapt@gmail.com> | Wed Feb 03 14:23:27 2021 +0100 |
tree | be3f12b41aedcd32a872c71307fc4f4d15110aa8 | |
parent | ee08a0d33fa0c7db9e982ec7b228b9d3399883ba [diff] |
Updates following KLayout DRC
This is the Google/EFabless/Skywater Caravel submission of the Amateur Radio Satellite Transceiver.
These blocks serve as the first pieces in a larger design of an open source amateur radio satellite transceiver - this is the first tapeout submission.
The design sources of the continued project can be found here: amsat_txrx_ic.
VCO Layout
A S-Band phase locked loop employing a differential ring oscillator VCO with quadrature outputs. CML (Current Mode Logic) and flip-flop based pre-scaler dividers are used with a fractional-N divider which uses a 3rd order MASH structure with dithering. Finally a PFD (Phase Frequency Detector) is combined with a charge pump with off chip filtering to complete the loop.
A cell based buffer is used to drive the external 100 ohm differential output.
Bandgap Layout
A bandgap reference with separate PTAT and CTAT currents. Provides less than +/-0.2% variation from -40 to 125 degrees celcius (tt simulation). 6 bits of trimming on both PTAT and CTAT allows less than 1% accuracy over process variations.
To install the environment used for development of this repository, follow these instructions.
git clone https://github.com/yrrapt/sky130_setup.git cd sky130_setup ./install_pdk.sh ./install_tools.sh
cd amsat_txrx_ic-caravel/xschem xschem
cd amsat_txrx_ic-caravel/gds klayout caravel.gds
cd amsat_txrx_ic-caravel/utils ./run_drc amsat_txrx_ic-caravel
cd amsat_txrx_ic-caravel/utils ./run_drc amsat_txrx_ic-caravel