SkyWater130 SAR ADC

Synchronous 8 bit SAR ADC generated using BAG3.

Inventory

This repo consists of bag3_sync_sar_adc and data/bag3_sync_sar_adc_data_skywater130. The later consists of yaml files that describe the required parameters of each circuit. The former consists of BAG3 generators. Please visit each repo individually to make sure you have the most up to date implementations.

Provided is a list of files with descriptions:

• Top level ADC
  • Generator: sar_sync_bootstrap.py
  • Specs (8 bit): specs_slice_sync_bootstrap.yaml
  • Specs (4 bit): specs_slice_sync_bootstrap_small.yaml
• Bootstrapped Sampler
  • Generates sampling switch
  • Generator: sampler_top.py
  • Specs: specs_clkgen_sync_sar.yaml
• Synchronous Logic
  • This block can be further split into the full 8 bit logic array with output registers, and the unit logic block for 1 bit
  • Generator (for all blocks): sar_logic_sync.py
  • Specs:
    • For top level: specs_logic_sync.yaml
    • For array: specs_logic_array_sync.yaml
    • For unit: For top level: specs_logic_unit_sync.yaml
    • For OAI logic gate in unit:
• MIM Cap DAC
  • This block generates an 8 bit capacitor dac of MIM caps
  • Generator (for all blocks): sar_cdac.py
  • Specs:
    • For cap DAC: specs_cdac_mim.yaml
    • For switch bank: specs_capdrv_unit.yaml
    • For single MIM capacitor: specs_cap_mim.yaml
• Comparator
  • This block contains a wrapper around a comparator. A strongARM is used.
  • Generator: sar_comp.py
  • Specs: specs_comp_sa.yaml
• Clock generator
  • Divides input clock by 16 for a reset/sampling signal, provides buffering for clock signals
  • Generator: clk_sync_sar.py
  • Specs: specs_clkgen_sync_sar.yaml
• Digital blocks
  • Contains BAG generator code for some standard logic gates (inv, nand, flip flop, latch, etc.)
  • Generator: digital.py
  • Does not have any dedicated yaml files
• Util Folder
  • Contains layout helper functions
  • folder

Setup

This generator will only work inside a BAG3 workspace ( template repo ). See the ReadMe for the template repo for workplace setup instructions.

After cloning, add

bag3_sync_sar_adc/src 

to .bashrc_pypath .

If you wish to use this generator with Virtuoso, also add

bag3_sync_sar_adc/src/OA/bag3_sync_sar_adc

to your cds.lib

To generate a design from this repo run the following command in your workspace:

./gen_cell.sh data/bag3_sync_sar_adc_data_skywater130/specs_gen/sar_lay/your_yaml.yaml

Caveats

This generator has only been verified LVS and DRC clean on configurations in the provided yamls.

Licensing

This library is licensed under the BSD, 3-Clause license. See here for full text of the BSD, 3-Clause license.