MP20043 –DUAL-CHANNEL, 300mA LDO WITH PROGRAMMABLE OUTPUT VOLTAGE
APPLICATION INFORMATION
Input capacitor of larger value will help improve
line transient response with the drawback of
increased size. Ceramic capacitors are
preferred, but tantalum capacitors may also
sufficient.
Output Voltage
The output
voltage
of
MP20043
is
programmable with setting different states of P1
PIN and P2 PIN. For combination A, the setting
rule is as the following table:
Output Capacitor Selection
Table 1 Programmable Output Voltage
Setting (Combination A)
The MP20043 is designed specifically to work
with very low ESR ceramic output capacitor in
space-saving and performance consideration. A
ceramic capacitor in the range of 0.47µF and
10µF, and with ESR lower than 1ꢀ is suitable
for the MP20043 application circuit. Output
capacitor of larger values will help to improve
load transient response and reduce noise with
the drawback of increased size.
P1 State P2 State
VOUT1
VOUT2
L
L
1.5V
2.8V
L
H
1.8V
1.8V
1.8V
1.8V
2.7V
2.8V
2.9V
2.8V
2.9V
2.8V
2.7V
2.6V
2.8V
2.8V
2.9V
3.3V
L
Open
L
H
H
H
H
Open
L
Open
Open
Open
H
.
Open
For example, when P1 and P2 are both open,
output voltage of channel 1 is 2.8V, and the
output voltage of channel 2 is 3.3V.
Power Dissipation
The power dissipation for any package depends
on the thermal resistance of the case and circuit
board, the temperature difference between the
junction and ambient air, and the rate of airflow.
The power dissipation across the device can be
represented by the equation:
P = (VIN - VOUT) ×IOUT
The allowable power dissipation can be
calculated using the following equation:
P(MAX) = (TJunction - TAmbient) / θJA
Where (TJunction - TAmbient) is the temperature
difference between the junction and the
surrounding environment, θJA is the thermal
resistance from the junction to the ambient
environment. Connect the GND pin of MP20043
to ground using a large pad or ground plane
helps to channel heat away.
Input Capacitor Selection
Using a capacitor whose value is >0.47µF on
the MP20043 input and the amount of
capacitance can be increased without limit.
MP20043 Rev.0.91
10/10/2011
www.MonolithicPower.com
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12
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