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#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: 8000,
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: 8000,
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: 8000,
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>
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