ELECTROSTATIC SENSITIVE DEVICE
OBSERVE HANDLING PRECAUTIONS
MITSUBISHI RF POWER MODULE
RoHS COMPLIANCE
RA55H3847M
Output Power Control:
Depending on linearity, the following two methods are recommended to control the output power:
a) Non-linear FM modulation:
By the gate voltage (V
GG
).
When the gate voltage is close to zero, the RF input signal is attenuated up to 60 dB and only a small leakage
current flows from the battery into the drain.
Around V
GG
=4V, the output power and drain current increases substantially.
Around V
GG
=4.5V (typical) to V
GG
=5V (maximum), the nominal output power becomes available.
b) Linear AM modulation:
By RF input power P
in
.
The gate voltage is used to set the drain’s quiescent current for the required linearity.
Oscillation:
To test RF characteristics, this module is put on a fixture with two bias decoupling capacitors each on gate and
drain, a 4.700 pF chip capacitor, located close to the module, and a 22 µF (or more) electrolytic capacitor.
When an amplifier circuit around this module shows oscillation, the 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 Z
L
=50Ω?
c) Is the source impedance Z
G
=50Ω?
Frequent on/off switching:
In base stations, frequent on/off switching can cause thermal expansion of the resin that coats the transistor chips
and can result in reduced or no output power. The bond wires in the resin will break after long-term thermally
induced mechanical stress.
Quality:
Mitsubishi Electric is not liable for failures resulting from base station operation time or operating conditions
exceeding those of mobile radios.
This module technology results from more than 20 years of experience, field proven in tens of millions of mobile
radios. Currently, most returned modules show failures such as ESD, substrate crack, and transistor burnout,
which are caused by improper handling or exceeding recommended operating conditions. Few degradation
failures are found.
Keep safety first in your circuit designs!
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. 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.
RA55H3847M
MITSUBISHI ELECTRIC
8/8
12 Jun 2007
MITSUBISHI [ MITSUBISHI ELECTRIC SEMICONDUCTOR ]
