LM9061 datasheet(11/14 Pages) NSC

11 / 14 page

Application Hints (Continued)

manufacturer for all of the MOSFETs in the array Also all

MOSFETs should have the same style heat sink or ideally

all mounted on the same heat sink The electrical connec-

tion of the MOSFETs should get special attention With typi-

cal RDS(ON) values in the range of tens of milli-Ohms a

poor electrical connection for one of the MOSFETs can ren-

der it useless in the circuit

Figure 7 shows a circuit with four parallel NDP706A

MOSFETs This particular MOSFET has a typical RDS(ON)

of 0013X with a TJ of 25 C and 0020X with a TJ of

125 C

With the VDS threshold voltage being set to 500 mV this

circuit will provide a typical maximum load current of 150A

at 25 C and a typical maximum load current of 100A at

125 C The maximum dissipation per MOSFET will be

nearly 20W at 25 C and 125W at 125 C With up to 20W

being dissipated by each of the four devices an effective

heat sink will be required to keep the TJ as low as possible

when operating near the maximum load currents

TLH12317 – 15

FIGURE 7 Driving Multiple MOSFETs

LM9061 Datasheet(PDF) 11 Page - National Semiconductor (TI)