MCP1700 datasheet(13/24 Pages) MICROCHIP

13 / 24 page

DS21826B-page 13

MCP1700

6.0

APPLICATION CIRCUITS &

ISSUES

6.1

Typical Application

The MCP1700 is most commonly used as a voltage

regulator. It’s low quiescent current and low dropout

voltage make it ideal for many battery-powered

applications.

FIGURE 6-1:

Typical Application Circuit.

6.1.1

APPLICATION INPUT CONDITIONS

6.2

Power Calculations

6.2.1

POWER DISSIPATION

The internal power dissipation of the MCP1700 is a

function of input voltage, output voltage and output

current. The power dissipation, as a result of the

quiescent current draw, is so low, it is insignificant

(1.6 µA x VIN). The following equation can be used to

calculate the internal power dissipation of the LDO.

EQUATION 6-1:

The

maximum

continuous

operating

junction

temperature specified for the MCP1700 is +125°C. To

estimate the internal junction temperature of the

MCP1700, the total internal power dissipation is

multiplied by the thermal resistance from junction to

ambient (R

θJA). The thermal resistance from junction to

ambient for the SOT-23 pin package is estimated at

230°C/W.

EQUATION 6-2:

The maximum power dissipation capability for a

package can be calculated given the junction-to-

ambient thermal resistance and the maximum ambient

temperature for the application. The following equation

can be used to determine the package maximum

internal power dissipation.

EQUATION 6-3:

EQUATION 6-4:

EQUATION 6-5:

Package Type = SOT-23

Input Voltage Range = 2.3V to 3.2V

VIN maximum = 3.2V

VOUT typical = 1.8V

IOUT = 150 mA maximum

MCP1700

GND

VOUT

VIN

CIN

1µF Ceramic

COUT

1 µF Ceramic

VOUT

VIN

(2.3V to 3.2V)

1.8V

IOUT

150 mA

PLDO

VIN MAX)

()

VOUT MIN

()

–

() I

OUT MAX

)

()

PLDO = LDO Pass device internal power dissipation

VIN(MAX) = Maximum input voltage

VOUT(MIN) = LDO minimum output voltage

TJMAX

()

PTOTAL RθJA

TAMAX

TJ(MAX) = Maximum continuous junction

temperature.

PTOTAL = Total device power dissipation.

θJA = Thermal resistance from junction to ambient.

TAMAX = Maximum ambient temperature.

PDMAX

()

TJMAX

()

TAMAX

()

–

()

---------------------------------------------------

PD(MAX) = Maximum device power dissipation.

TJ(MAX) = Maximum continuous junction

temperature.

TA(MAX) = Maximum ambient temperature.

θJA = Thermal resistance from junction to ambient.

TJRISE

()

PDMAX

()

TJ(RISE) = Rise in device junction temperature over

the ambient temperature.

PTOTAL = Maximum device power dissipation.

θJA = Thermal resistance from junction to ambient.

TJRISE

()

TJ = Junction Temperature.

TJ(RISE) = Rise in device junction temperature over

the ambient temperature.

TA = Ambient temperature.

MCP1700 Datasheet(PDF) 13 Page - Microchip Technology

MCP1700 Datasheet(HTML) 13 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

Datasheet Download

Link URL