MHW803–2

4

MOTOROLA RF DEVICE DATA

APPLICATIONS INFORMATION

NOMINAL OPERATION

All electrical specifications are based on the nominal

conditions of Vs1 = Vs2 = Vs3 = 7.5 Vdc (Pins 2, 3, 4) and Pout

equal to 2 watts. With these conditions, maximum current

density on any device is 1.5 x 105 A/cm2 and maximum die

temperature with 100

°C case operating temperature is

165

°C. While the modules are designed to have excess gain

margin with ruggedness, operation of these units outside the

limits of published specifications is not recommended unless

prior communications regarding intended use have been

made with the factory representative.

GAIN CONTROL

The module output should be limited to 2 watts. The pre-

ferred method of power output control is to fix Vs1 = Vs2 = Vs3

= 7.5 Vdc (Pins 2, 3, 4), Pin (Pin 1) at 1 mW, and vary VCont

(Pin 1) voltage.

DECOUPLING

Due to the high gain of the three stages and the module

size limitation, external decoupling networks require careful

consideration. Pins 2, 3 and 4 are internally bypassed with a

0.018

µF chip capacitor which is effective for frequencies

from 5 MHz through 905 MHz. For bypassing frequencies

below 5 MHz, networks equivalent to that shown in Figure 1

are recommended. Inadequate decoupling will result in spu-

rious outputs at certain operating frequencies and certain

phase angles of input and output VSWR.

LOAD MISMATCH

During final test, each module is load mismatch tested in a

fixture having the identical decoupling networks described in

Figure 1. Electrical conditions are Vs1 = Vs2 = Vs3 equal to 10

Vdc, VSWR equal to 10:1, and output power equal to 3 watts.