// SAME Analog Modular Ecosystem
//
// / SPDX-FileCopyrightText: 2026 Denis Chevalier <perso@denischevalier.fr>
// / SPDX-License-Identifier: CC-BY-SA-4.0
// / SPDX-License-Identifier: CERN-OHL-S-2.0+
// / SPDX-License-Identifier: GPL-3.0-or-later
//
// The prose, explanatory text, rendered figures, tables, and mathematical
// content of this specification are licensed under CC BY-SA 4.0. If a later
// version of CC BY-SA is published, the author grants permission to distribute
// this work under that later version as well.
//
// Hardware designs contained herein (schematics, PCB layouts, mechanical
// drawings, and CAD models) are licensed under CERN-OHL-S-2.0+.
//
// All executable code, helper libraries (`lib/*`), metrology assertions, and
// embedded verification scripts throughout the source documents are licensed
// under the GNU General Public License v3.0 or later (GPL-3.0-or-later).

#import "../lib/unify.typ": qty, unit
#import "@preview/cetz:0.5.2"
#import "@preview/cetz-plot:0.1.4": plot

#figure(
  cetz.canvas({
    import cetz.draw: *

    plot.plot(
      size: (12, 6),
      x-mode: "log",
      y-mode: "linear",
      x-label: [Frequency $f$ ($unit("Hz")$)],
      y-label: [$upright("PSRR")(f)$ ($unit("dB")$)],
      x-min: 1,
      x-max: 1000000,
      y-min: 0,
      y-max: 140,
      x-grid: "minor",
      y-grid: "minor",
      {
        // 500 kHz PWAM Carrier vertical reference line
        plot.add(
          ((500000, 0), (500000, 140)),
          style: (stroke: (paint: luma(120), thickness: 0.8pt, dash: "dashed")),
          label: none,
        )
        // General purpose (TL07x): PSRR_DC = 100 dB, fp1 = 1 kHz, fp2 = 100 kHz
        plot.add(
          style: (stroke: (dash: "solid")),
          label: [TL07x],
          domain: (1, 1000000),
          samples: 1000,
          f => (
            100
              - 10 * calc.log(1 + calc.pow(f / 1000, 2), base: 10)
              - 10 * calc.log(1 + calc.pow(f / 100000, 2), base: 10)
          ),
        )
        // Low noise (OPA211): PSRR_DC = 130 dB, fp1 = 300 Hz, fp2 = 50 kHz
        plot.add(
          style: (stroke: (dash: "dotted")),
          label: [OPA211],
          domain: (1, 1000000),
          samples: 1000,
          f => (
            130
              - 10 * calc.log(1 + calc.pow(f / 300, 2), base: 10)
              - 10 * calc.log(1 + calc.pow(f / 50000, 2), base: 10)
          ),
        )
        // Precision low noise (LT1028): PSRR_DC = 120 dB, fp1 = 300 Hz, fp2 = 100 kHz
        plot.add(
          style: (stroke: (dash: "dashed")),
          label: [LT1028],
          domain: (1, 1000000),
          samples: 1000,
          f => (
            120
              - 10 * calc.log(1 + calc.pow(f / 300, 2), base: 10)
              - 10 * calc.log(1 + calc.pow(f / 100000, 2), base: 10)
          ),
        )
      },
    )
  }),
  caption: [Power supply rejection ratio ($upright("PSRR")$) degradation across frequency, highlighting the reduced rejection at the $qty(500, "kHz")$ PWAM carrier frequency],
) <figure-power-supply-noise-coupling-mathematical-model>