49 lines
1.6 KiB
HTML
49 lines
1.6 KiB
HTML
<html><head>
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<meta http-equiv="content-type" content="text/html; charset=windows-1252"><style>#header + #content > #left > #rlblock_left,
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#content > #right > .dose > .dosesingle,
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#content > #center > .dose > .dosesingle
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{display:none !important;}</style><style>img[src="http://s05.flagcounter.com/count/pTvk/bg=FFFFFF/txt=000000/border=CCCCCC/columns=6/maxflags=36/viewers=0/labels=0/"]
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{display:none !important;}</style></head><body><h1>MOSFET Beta</h1>
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We use a parameter called "beta" to describe the behavior of a MOSFET. The default value is small (20m), which is appropriate for a signal MOSFET. To simulate
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a power MOSFET, use a larger value like 80.
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<p>
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This worksheet will calculate the value of beta for a particular MOSFET, given Rds(on).
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<p>
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<script>
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function units(x) {
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x = x.trim();
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if (x.match(/m$/)) {
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x = x.replace(/m$/, "");
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return .001 * x;
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}
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// don't think we need this but you never know
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if (x.match(/u$/)) {
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x = x.replace(/u$/, "");
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return 1e-6 * x;
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}
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return x;
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}
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function calc() {
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var rds = units(document.getElementById('rds').value);
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var vgs = units(document.getElementById('vgs').value);
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var vt = units(document.getElementById('vt').value);
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var beta = Math.abs(1/(rds*(vgs-vt)));
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document.getElementById('result').innerHTML = "beta = " + beta;
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}
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</script>
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<form action="/action_page.php">
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Rds(on) (Ω): <input type="text" id="rds" oninput="calc()"><br>
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Vgs (V): <input type="text" id="vgs" oninput="calc()"><br>
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Threshold (V): <input type="text" id="vt" oninput="calc()"><br>
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</form>
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<div id="result">
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</div>
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</body></html>
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