MITSUBISHI RF POWER MODULE
ELECTROSTATIC SENSITIVE DEVICE
OBSERVE HANDLING PRECAUTIONS
RA30H4452M
Output Power Control:
Depending on linearity following 2 methods are recommended to control the output power:
a) Non-linear FM modulation:
By Gate voltage VGG
.
When the Gate voltage is close to zero, the RF input signal is attenuated up to 60dB and only a small leakage
current is flowing from the battery into the Drain.
Around VGG=3.5V the output power and Drain current increases strongly.
Around VGG=4V, latest at VGG=5V, the nominal output power becomes available.
b) Linear AM modulation:
By RF input power Pin.
The Gate voltage is used to set the Drain quiescent current for the required linearity.
Oscillation:
To test RF characteristic this module is put on a fixture with 2 bias decoupling capacitors each on Gate and Drain, a
4.700pF chip capacitor, located close to the module, and a 22µF (or more) electrolytic capacitor.
When an amplifier circuit around this module shows oscillation following may be checked:
a) Do the bias decoupling capacitors have a low inductance pass to the case of the module ?
b) Is the load impedance ZL=50W ?
c) Is the source impedance ZG=50W ?
Frequent on/off switching:
In Base Stations frequent on/off switching can result in reduced or no output power, when the resin that coats the
transistor chips gets thermally expanded by the on/off switching. The bond wires in the resin will break after long time
thermally induced mechanical stress.
Quality:
MITSUBISHI ELECTRIC cannot take any liability for failures resulting from Base Station operation time or operating
conditions exceeding those in Mobile Radios.
The technology of this module is the result of more than 20 years experience, field proven in several 10 million
Mobile Radios. Today most returned modules show failures as ESD, substrate crack, transistor burn-out, etc which
are caused by handling or operating conditions. Few degradation failures can be found.
Keep safety first in your circuit
Mitsubishi Electric Corporation puts the maximum effort into making semiconductor products better and more
reliable, but there is always the possibility that trouble may occur with them. Trouble with semiconductors may lead
to personal injury, fire or property damage. Remember to give due consideration to safety when making your circuit
designs, with appropriate measures such as (i) placement of substitutive, auxiliary circuits, (ii) use of
non-flammable material or (iii) prevention against any malfunction or mishap.
RA30H4452M
2 Dec 2002
MITSUBISHI ELECTRIC
8/9
MITSUBISHI [ Mitsubishi Group ]
