SN75372

DUAL MOSFET DRIVER

SLLS025A − JULY 1986

3−8

POST OFFICE BOX 655303

POST OFFICE BOX 1443

APPLICATION INFORMATION

driving power MOSFETs

The drive requirements of power MOSFETs are much lower than comparable bipolar power transistors. The

input impedance of a FET consists of a reverse biased PN junction that can be described as a large capacitance

in parallel with a very high resistance. For this reason, the commonly used open-collector driver with a pullup

resistor is not satisfactory for high-speed applications. In Figure 12(a), an IRF151 power MOSFET switching

an inductive load is driven by an open-collector transistor driver with a 470-

Ω pullup resistor. The input

5 V

7

4

8

3

5

1

2

6

TLC555P

1/2 SN75447

470

Ω

48 V

M

t − Time −

µs

(b)

(a)

IRF151

4

3

2

1

0

0

0.5

1

1.5

2

2.5

3

Figure 13. Power MOSFET Drive Using SN75447