MHW954 Ver la hoja de datos (PDF) - Motorola => Freescale

Número de pieza

componentes Descripción

Fabricante

MHW954

UHF Power Amplifiers

Motorola => Freescale 

APPLICATIONS INFORMATION

NOMINAL OPERATION

All electrical specifications are based on the nominal

conditions of Vs1 = Vs2 = Vs3 = 7.2 Vdc (Pins 2, 4, 5) and Vb

= 5.0 Vdc (Pin 3) for MHW903/953. Nominal conditions are

Vs1 = Vs2 = 7.2 Vdc (Pins 2 and 4) and Vb = 4.5 Vdc (Pin 3) for

MHW954. With these conditions, maximum current density on

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

is 165°C. While the modules are designed to have excess gain

margin with ruggedness, operation of these units outside the

published specifications is not recommended unless prior

communications regarding intended use have been made

with the factory representative.

GAIN CONTROL

The module output power should be limited to specified

value. The preferred method of power control for the

MHW903/953 is to fix Vs1 = Vs2 = Vs3 = 7.2 Vdc, Vb = 5.0 Vdc,

Pin (Pin 1) at 1.0 mW, and vary Vcont (Pin 1) voltage. For the

MHW954, fix Vs1 = Vs2 = 7.2 Vdc and Vb = 4.5 Vdc; then vary

Pin (Pin 1) to control Pout (Pin 5).

DECOUPLING

Due to the high gain of the four stages and the module size

limitation, external decoupling networks require careful con-

sideration, Pins 2, 3, 4 and 5 are internally bypassed with a

0.018 µF chip capacitor which is effective for frequencies from

5.0 MHz through 940 MHz. For bypassing frequencies below

5.0 MHz, networks equivalent to that shown in Figure 1 are

recommended. Inadequate decoupling will result in spurious

outputs at certain operating frequencies and certain phase

angles of input and output VSWR.

MOUNTING CONSIDERATIONS

For the MHW903 Series module, mounting is generally

accomplished by soldering the flange to a suitable heat sink.

This can be done with a low temperature solder such as 52%

In, 48% Sn and type “R” Flux which liquifies below 150°C.

Under no circumstances should the MHW903 Series modules

be heated to a temperature greater than ≈165°C. Internal

construction of the module has been achieved using 36% Tin,

62% lead, 2% silver solder which liquifies at 179– 180°C.

The modules are NOT hermetic. Do not immerse a module

in a flux cleaning solution or other liquids under any

circumstances.

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 = 9.0 Vdc

(Pins 2, 4, 5), and Vb = 5.0 Vdc (Pin 3), Pin = 2.0 mW (12.5%

duty cycle, 4.6 ms period), VSWR equal to 10:1, and output

power equal to 4.5 watts.

MOTOROLA RF DEVICE DATA

MHW903 MHW953 MHW954

5

Share Link: