How can I test a MOSFET for drain-source on-resistance on my curve tracer?

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Drain-Source On-Resistance - RDS(on) What is drain-source on-resistance? Drain-source on-resistance (RDS(on)) is the resistance between the drain and the source of a MOSFET when a specific gate-to-source voltage (VGS) is applied to bias the device to the on state. As the VGS increases, the on-resistance generally decreases. The measurement is made in the ohmic (i.e. linear) region of the device. Generally speaking, the lower the MOSFET on-resistance, the better. One of the ways to trace this resistance is to use a curve tracer. On a curve tracer, the so called &ldquo;Collector Supply&rdquo; drives the drain while the &ldquo;Step Generator&rdquo; drives the gate. For step-by-step instructions on how to test a MOSFET for drain-source on-resistance using a curve tracer, see below. For instructions on how to use an oscilloscope or SMU to measure MOSFET on-resistance, see our &ldquo; What is the drain-source on-resistance of a MOSFET? &rdquo; FAQ. What the display shows: The display shows VDS on the horizontal axis, and the resulting ID on the vertical axis. The specification is met when at the specified VDS, VDS/ID is less than or equal to the specified maximum. How to test a MOSFET for drain-source on-resistance on a curve tracer: 1. Under Controls, set: &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; A:Max Peak Volts to the lowest setting above the specified V DS &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; B: Max Peak Power Watts to the lowest setting that satisfies (I D x V DS ) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; C: Collector Supply Polarity to (+DC) for N-channel or (-DC) for P-channel&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; D: Horizontal Volts/Div to display V DS &nbsp;between the 5th and 10 th horizontal divisions &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; E: Vertical Current/Div to display I D &nbsp;between the 5th and 10th vertical divisions &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; F: Number of steps to minimum (zero) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; G: Step Generator to Voltage &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; H: Step Generator Polarity to apply forward bias (+ for N-channel), &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp; (- for P-channel) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; I: Step/Offset Ampl to approx 50% of the specified V GS &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; J: Pulse to Long&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; K: Configuration to (Base/Step Gen, Emitter/Common) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; L: Variable Collector Supply to minimum % (full ccw) &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; M: DotCursor ON 2. Apply power to the MOSFET: &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; A: Position the Left/Right switch as appropriate &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; B: Slowly increase the Variable Collector Supply until the specified V DS &nbsp;is reached 3. Compare to data sheet specifications: &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; A: Check that V DS /I D is less than or equal to the specified minimum Tektronix Curve Tracers are discontinued products. More efficient and accurate methodologies and solutions have been designed to support curve tracing functionality on a much more compact form factor. One such solution is based on using a dual channel SMU or two single channel SMUs and software to control the bias voltage step generation and the relative drain to source voltage drop. To learn more, see our &ldquo; What is the drain-source on-resistance of a MOSFET? &rdquo; FAQ.

How can I test a MOSFET for drain-source on-resistance on my curve tracer?

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What is drain-source on-resistance?

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How to test a MOSFET for drain-source on-resistance on a curve tracer: