SN75372

DUAL MOSFET DRIVER

SLLS025A – JULY 1986

3–8

POST OFFICE BOX 655303

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