| P+ poly precision resistors |
| --------------------------- |
| |
| Spice Model Information |
| ~~~~~~~~~~~~~~~~~~~~~~~ |
| |
| - Cell Name: :cell:`res_high_po_XpXX`, :cell:`sky130_fd_pr__res_high_po` |
| - Model Type: subcircuit |
| |
| Operating ranges where SPICE models are valid |
| |
| - :math:`|V_{r0} – V_{r1}| = 0` to 5.0V |
| - Currents up to 500 µA/µm of width (preferred use ≤ 100 µA/µm) |
| |
| Details |
| ~~~~~~~ |
| |
| The resistors have 5 different fixed widths, plus a variable W/L option. |
| |
| - 0.35 (0p35) |
| - 0.69 (0p69) |
| - 1.41 (1p41) |
| - 2.85 (2p83) |
| - 5.73 (5p73) |
| |
| They are modeled as subcircuits, using a conventional resistor model combined with the capacitance under the resistor, as well as matching parameters and temperature coefficients. The fixed-width resistors may only be used in the above configurations. Each resistor end is contacted using a slot licon. Length is variable and measured between the front ends of the slot licons. |
| |
| The fixed-width resistors are modeled using the equation |
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| *\ :math:`R_0`\ * = head/tail resistance [Ω] (dominated by the slot licons) |
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| *\ :math:`R_1`\ * = body resistance [Ω/µm] = :math:`R_{SH}`/W |
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| A top-down schematic drawing of the precision resistor is shown below. |
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| |res_high_po| |
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| In addition to the :math:`R_0` and :math:`R_1` values, several fixed-value resistors are measured at e-test, as shown in the table below: |
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| .. include:: res_high-table0.rst |
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| |
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| More details on the use of the precision resistors, and their models, are in the document ***SKY130 process Family Device Models*** (002-21997), which can be obtained from SkyWater upon request. |
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| The symbols for the 300 ohm/sq precision resistors are shown below: |
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| |symbol-res_high_po_0p35| |symbol-res_high_po_0p69| |
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| :model:`sky130_fd_pr__res_high_po_0p35` :model:`sky130_fd_pr__res_high_po_0p69` |
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| |symbol-res_high_po_1p41| |symbol-res_high_po_2p85| |
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| :model:`sky130_fd_pr__res_high_po_1p41` :model:`sky130_fd_pr__res_high_po_2p85` |
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| |symbol-res_high_po_5p73| |
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| :model:`sky130_fd_pr__res_high_po_5p73` |
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| A generic version of the poly resistor is also available, which permits user inputs for W and L, and connections in series or parallel. |
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| |symbol-res_high_po| |
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| .. |res_high_po| image:: res_high_po.svg |
| .. |symbol-res_high_po_0p35| image:: symbol-res_high_po_0p35.svg |
| .. |symbol-res_high_po_0p69| image:: symbol-res_high_po_0p69.svg |
| .. |symbol-res_high_po_1p41| image:: symbol-res_high_po_1p41.svg |
| .. |symbol-res_high_po_2p85| image:: symbol-res_high_po_2p85.svg |
| .. |symbol-res_high_po_5p73| image:: symbol-res_high_po_5p73.svg |
| .. |symbol-res_high_po| image:: symbol-res_high_po.svg |
| |
