RLP03N06CLE

Temperature Dependence of Current Limiting and
Switching Speed Performance
The RLD03N06CLE, CLESM and RLP03N06CLE are monolithic power devices which incorporate a Logic Level power MOSFET transistor with a current sensing scheme and control circuitry to enable the device to self limit the drain source current flow. The current sensing scheme supplies current to a resistor that is connected across the base to emitter of a bipolar transistor in the control section. The collector of this bipolar transistor is connected to the gate of the power MOSFET transistor. When the ratiometric current from the current sensing reaches the value required to forward bias the base emitter junction of this bipolar transistor, the bipolar "turns on". A resistor is incorporated in series with the gate of the power MOSFET transistor allowing the bipolar transistor to adjust the drive on the gate of the power MOSFET transistor to a voltage which then maintains a constant current in the power MOSFET transistor. Since both the
ratiometric current sensing scheme and the base emitter unction voltage of the bipolar transistor vary with temperature, the current at which the device limits is a function of temperature. This dependence is shown in Figure 3.

The resistor in series with the gate of the power MOSFET transistor also results in much slower switching performance than in standard power MOSFET transistors. This is an advantage where fast switching can cause EMI or RFI. The switching speed is very predictable.