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  2. def/
  3. doc/
  4. gds/
  5. lef/
  6. macros/
  7. mag/
  8. maglef/
  9. ngspice/
  10. openlane/
  11. qflow/
  12. scripts/
  13. spi/
  14. utils/
  15. verilog/
  16. xschem/
  17. .travis.yml
  18. info.yaml
  19. LICENSE
  20. Makefile
  21. mpw-one-b.md
  22. README.md
README.md

Amateur Radio Satellite Transceiver (SKY130) - Caravel Submission

This is the Google/EFabless/Skywater Caravel submission of the Amateur Radio Satellite Transceiver.

Design

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.

1.3 - 3.6 GHz Fractional-N Phase Locked Loop

pll 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

bandgap 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.

Using the sources

To install the environment used for development of this repository, follow these instructions.

  1. Install the tools:
git clone https://github.com/yrrapt/sky130_setup.git
cd sky130_setup
./install_pdk.sh
./install_tools.sh
  1. View schematics:
cd amsat_txrx_ic-caravel/xschem
xschem
  1. View layout:
cd amsat_txrx_ic-caravel/gds
klayout caravel.gds
  1. Run DRC:
cd amsat_txrx_ic-caravel/utils
./run_drc amsat_txrx_ic-caravel
  1. Run LVS:
cd amsat_txrx_ic-caravel/utils
./run_drc amsat_txrx_ic-caravel