MP20142 –DUAL-CHANNEL, 200mA LDO WITH PROGRAMMABLE OUTPUT VOLTAGE

MP20142 Rev.0.9

www.MonolithicPower.com

12

7/12/2010

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APPLICATION INFORMATION

Output Voltage

The

output

voltage

of

MP20142

is

programmable with setting different states of P1

PIN and P2 PIN. The setting rule is as the

following table:

Table 1 Programmable Output Voltage

Setting

P1 State

P2 State

L

L

1.5V

1.8V

L

H

1.5V

2.8V

L

Open

1.8V

3.0V

H

L

2.6V

3.0V

H

H

2.8V

3.0V

H

Open

2.8V

3.3V

Open

L

3.0V

3.0V

Open

H

3.0V

3.3V

Open

Open

3.3V

3.3V

For example, when P1 and P2 are both open,

output voltage of channel 1 is 3.3V, 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:

The allowable power dissipation can be

calculated using the following equation:

difference between the junction and the

resistance from the junction to the ambient

environment. Connect the GND pin of MP20142

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 MP20142 input and the amount of

capacitance can be increased without limit.

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 Capacitor Selection

The MP20142 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 1Ω is suitable

for the MP20142 application circuit. Output

capacitor of larger values will help to improve

load transient response and reduce noise with

the drawback of increased size.