0

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0.40

10

1.0

-1

0.5

SINGLE PULSE

0.1

0.3

0.7

0.05

D = 0.9

Peak TJ = PDM x ZθJC + TC

Duty Factor D =

2

t2

t1

Note:

RECTANGULAR PULSE DURATION (seconds)

Figure 5. Maximum Effective Transient Thermal Impedance Junction-to-Case vs Pulse Duration

Typical Performance Curves

VRF141G

Figure 7. 175 MHz T est Circuit

C1 - Arco 402, 1.5 ±20 pF

C2 - Arco 406, 15 ±115 pF

C3, C4, C8, C9, C10 - 1000 pF Chip

C5, C11 - 0.1 mF Chip

C6 - 330 pF Chip

C7 - 200 pF and 180 pF Chips in Parallel

C12 - 0.47 mF Ceramic Chip, Kemet 1215 or Equivalent

C13 - Arco 403, 3.0 ±35 pF

L1 - 10 T urns AWG #16 Enameled Wire,

Close Wound, 1/4, I.D.

L2 - Ferrite Beads of Suitable Material for

1.5±2.0 mH Total Inductance

R1 - 100 Ohms, 1/2 W

R2 - 1.0 kOhm, 1/2 W

Unless Otherwise Noted, All Chip Capacitors are ATC

Type 100B or Equivalent.

T1 - 9:1 RF Transformer. Can be made of 15±18 Ohms

Semirigid Co-ax, 62 ±90 Mils O.D.

T2 - 1:9 RF Transformer . Can be made of 15±18 Ohms

Semirigid Co-ax, 70 ±90 Mils O.D.

,

Board Material - 0.062

Fiberglass (G10),

NOTE: For stability, the input transformer T1 must be loaded

with ferrite toroids or beads to increase the common

mode inductance. For operation below 100 MHz. The

same is required for the output transformer.

See pictures for construction details.

-

DUT

Connections to

low impedance

windings

9:1

Impedance

ratio

4:1

Impedance

ratio

High

impedance

windings

Center

tap

Center

tap

28V

Output

L1

L2

C1

C2

C3

C4

C5

C6

C7

C8

C9

C10

C11

C12

T2

C13

Bias 0-6V

R1

R2

T1

Input

+