ARF475FL

Table 1 - Typical Series Equivalent Large Signal Input - Output Impedance

Freq. (MHz)

Zin (Ω) gate to gate

Z

30

60

90

120

150

5.2 -j10

1.37 -j5.2

.53 -j2.6

.25 -j1.0

.25 +j0.2

41 -j20

26 -j25

16 -j23

10 -j20

6.7 -j17

Z

Conjugate of optimum load for 600 Watts peak output at Vdd = 150V

25% duty cycle and PW = 5ms

Figure 5b, TRANSIENT THERMAL IMPEDANCE MODEL

Note:

Duty Factor D =

t1/t

2

Peak TJ = PDM x ZθJC + TC

t1

t2

SINGLE PULSE

1.0

RECTANGULARPULSEDURATION(SECONDS)

FIGURE 5a, MAXIMUM EFFECTIVE TRANSIENT THERMAL IMPEDANCE, JUNCTION-TO-CASE vs PULSE DURATION

0.18

0.16

0.14

0.12

0.10

0.08

0.06

0.04

0.02

0

0.5

0.1

0.3

0.7

0.05

D = 0.9

0.0755

0.0893

0.0135F

0.161F

Dissipated Power

(Watts)

T

T

Z

impedances: Case to sink, sink to

ambient, etc. Set to zero when modeling

only the case to junction.