> ## Documentation Index
> Fetch the complete documentation index at: https://docs.atopile.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Crystal_Oscillator

## Interfaces

<ParamField path="xtal_if" type="XtalIF" />

## Global Attributes

These attributes are available to all modules and interfaces in a design.

<ParamField path="lcsc_id" type="str">
  Assign the LCSC ID of the module.

  If set, this will tell the picker to select that part from LCSC for this block.
</ParamField>

<ParamField path="manufacturer" type="str">
  This module's manufacturer name, as a string.

  Only exact matches on the manufacturer's name will be found by the picker.
  It's recommended to fill this information based on what `ato create component`
  provides.
</ParamField>

<ParamField path="mpn" type="str">
  This module's manufacturer part number, as a string.

  For the picker to select the correct part from the manufacturer,
  this must be set.
</ParamField>

<ParamField path="package" type="str">
  The package of the module.

  This drives which components can be selected, and what footprint is used.

  Must exactly match a known package name.
</ParamField>

<ParamField path="exclude_from_bom" type="bool" />

<ParamField path="override_net_name" type="str">
  When set on an interface, this will override the net name of the interface.

  This is useful for renaming nets which are automatically generated.
</ParamField>

<ParamField path="required" type="bool">
  Only for ModuleInterfaces.
  If set to `True`, require that interface is connected to something outside
  of the module it's defined in.
</ParamField>

<RequestExample>
  ```ato Basic Usage theme={null}
  import Crystal_Oscillator, ElectricPower

  crystal_osc = new Crystal_Oscillator

  # Configure crystal parameters
  crystal_osc.crystal.frequency = 16MHz +/- 20ppm
  crystal_osc.crystal.load_capacitance = 18pF +/- 10%
  crystal_osc.crystal.equivalent_series_resistance = 80ohm +/- 20%
  crystal_osc.crystal.package = "HC49U"

  # Connect power for ground reference
  power_3v3 = new ElectricPower
  assert power_3v3.voltage within 3.3V +/- 5%
  crystal_osc.xtal_if.gnd ~ power_3v3.lv

  # Connect to microcontroller crystal pins
  microcontroller.xtal_in ~ crystal_osc.xtal_if.xin
  microcontroller.xtal_out ~ crystal_osc.xtal_if.xout

  # Load capacitors are automatically calculated:
  # C_load = (Crystal_load_cap - Stray_cap) * 2
  # Typically results in 22pF capacitors for 18pF crystal

  # Current limiting resistor prevents overdrive (optional)
  crystal_osc.current_limiting_resistor.resistance = 1kohm +/- 5%

  # Common frequencies: 8MHz, 12MHz, 16MHz, 20MHz, 25MHz
  # Used for: microcontroller clocks, RTC, timing references
  ```
</RequestExample>