MCP1726-0802ESLASHMF datasheet(18/32 Pages) MICROCHIP

18 / 32 page

MCP1726

DS20001936D-page 18

 2005-2014 Microchip Technology Inc.

5.0

APPLICATION CIRCUITS/

ISSUES

5.1

Typical Application

The MCP1726 is used for applications that require high

LDO output current and a power good output.

FIGURE 5-1:

Typical Application Circuit.

5.1.1

APPLICATION CONDITIONS

5.2

Power Calculations

5.2.1

POWER DISSIPATION

The internal power dissipation within the MCP1726 is a

function of input voltage, output voltage, output current

and quiescent current. The following equation can be

used to calculate the internal power dissipation for the

LDO.

EQUATION 5-1:

In addition to the LDO pass element power dissipation,

there is power dissipation within the MCP1726 as a

result of quiescent or ground current. The power

dissipation as a result of the ground current can be

calculated using the following equation:

EQUATION 5-2:

The total power dissipated within the MCP1726 is the

sum of the power dissipated in the LDO pass device

and the PI(GND) term. Because of the CMOS

construction, the typical IGND for the MCP1726 is

140 µA. Operating at a maximum of 3.63V results in a

power dissipation of 0.51 mW. For most applications,

this is small compared to the LDO pass device power

dissipation and can be neglected.

The

maximum

continuous

operating

junction

temperature specified for the MCP1726 is +125°C. To

estimate the internal junction temperature of the

MCP1726, the total internal power dissipation is

multiplied by the thermal resistance from junction to

ambient (R

JA) of the device. The thermal resistance

from junction to ambient for the 3x3 DFN package is

estimated at 64°C/W.

EQUATION 5-3:

Package Type = 8-Lead 3x3 DFN

Input Voltage Range = 3.3V ± 10%

VIN maximum = 3.63V

VIN minimum = 2.97V

VOUT typical = 2.5V

IOUT =1.0A maximum

10 µF

VOUT =2.5V @ 1A

10 µF

VIN =3.3V

Off

1000 pF

MCP1726-2.5

10 k



PWRGD

VIN

SHDN

GND

PWRGD

CDELAY

VOUT

VIN

LDO

IN MAX





OUT MIN



–

 I

OUT MAX







PLDO = LDO Pass device internal power

dissipation

VIN(MAX) = Maximum input voltage

VOUT(MIN) = LDO minimum output voltage

IGND



IN MAX



VIN



PI(GND) = Power dissipation due to the quiescent

current of the LDO

VIN(MAX) = Maximum input voltage

IVIN = Current flowing in the VIN pin with no

LDO output current (LDO quiescent

current)

JMAX



TOTAL





AMAX



TJ(MAX) = Maximum continuous junction

temperature

PTOTAL = Total device power dissipation

JA = Thermal resistance from

junction-to-ambient

TA(MAX) = Maximum ambient temperature

MCP1726-0802E/MF Datasheet(PDF) 18 Page - Microchip Technology

MCP1726-0802E/MF Datasheet(HTML) 18 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32

Datasheet Download

Link URL