AIC1730
PMAX = (TJ-TA)/(qJB + qBA
)
NOISE BYPASS CAPACITOR
Use a 0.1mF bypass capacitor at BP for low
where TJ-TA is the temperature difference
between the die junction and the surrounding air,
output voltage noise. Increasing the capacitance
such as 1mF will decrease the output noise,
however, values above 1mF provide no
qJB is the thermal resistance of the package, and
qBA is the thermal resistance through the PCB,
copper traces, and other materials to the
surrounding air.
performance
advantage
and
are
not
recommended.
As a general rule, the lower the temperature is,
the better the reliability of the device is. So the
PCB mounting pad should provide maximum
thermal conductivity to maintain low device
temperature.
POWER DISSIPATION
The maximum power dissipation of AIC1730
depends on the thermal resistance of the case
and circuit board, the temperature difference
between the die junction and ambient air, and
the rate of air flow. The rate of temperature rise is
greatly affected by the mounting pad
configuration on the PCB, the board material,
and the ambient temperature. When the IC
mounting with good thermal conductivity is used,
the junction will be low even if the power
dissipation is great.
The GND pin performs the dual function of
providing an electrical connection to ground and
channeling heat away. Therefore, connecting the
GND pin to ground with a large pad or ground
plane would increase the power dissipation and
reduce the device temperature.
The power dissipation across the device is P =
IOUT (VIN-VOUT).
The maximum power dissipation is:
100
10
100
m
m
OUT=1 F
COUT=2.2 F
C
10
1
1
STABLE REGION
STABLE REGION
0.1
0.01
0.1
0.01
50
100
50
100
150
150
IOUT (mA)
IOUT(mA)
10
AIC [ ANALOG INTERGRATIONS CORPORATION ]
