MCP1801T-1502I/OT Microchip Technology, MCP1801T-1502I/OT Datasheet - Page 14

• Manufacturer Part Number: MCP1801T-1502I/OT
• Description: High PSRR 150 mA LDO, Vin 10V max, Vout=1.5V, -40C to +85C, 5-SOT-23, T/R
• Manufacturer: Microchip Technology

MCP1801
6.0
6.1
The MCP1801 is most commonly used as a voltage
regulator. Its low quiescent current and low dropout
voltage make it ideal for many battery-powered
applications.
FIGURE 6-1:
6.1.1
6.2
6.2.1
The internal power dissipation of the MCP1801 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
(25.0 µA x V
calculate the internal power dissipation of the LDO.
EQUATION 6-1:
The maximum continuous operating temperature
specified for the MCP1801 is +85°C
internal junction temperature of the MCP1801, the total
internal power dissipation is multiplied by the thermal
resistance from junction to ambient (Rθ
resistance from junction to ambient for the SOT-23-5
pin package is estimated at 256°C/W.
DS22051B-page 14
I
50 mA
Where:
OUT
V
Input Voltage Range =
V
1.8V
P
V
OUT(MIN)
LDO
OUT
IN(MAX)
P
APPLICATION CIRCUITS &
ISSUES
Typical Application
Power Calculations
LDO
Package Type =
V
=
V
IN
APPLICATION INPUT CONDITIONS
POWER DISSIPATION
IN
OUT
(
maximum =
V
). The following equation can be used to
IN MAX )
C
1 µF Ceramic
=
=
=
OUT
typical =
(
V
I
OUT
OUT
NC
LDO Pass device internal power
dissipation
Maximum input voltage
LDO minimum output voltage
MCP1801
Typical Application Circuit.
)
–
=
V
OUT MIN
SOT-23-5
2.4V to 5.0V
5.0V
1.8V
50 mA maximum
SHDN
GND
V
(
IN
)
) I
.
×
To estimate the
JA
OUT MAX )
). The thermal
V
2.4V to 5.0V
C
1 µF
Ceramic
IN
IN
(
)
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:
Where:
Where:
Where:
Where:
P
T
T
T
T
T
P
P
T
D(MAX)
A(MAX)
J(RISE)
J(RISE)
J(MAX)
J(MAX)
TOTAL
TOTAL
AMAX
Rθ
Rθ
Rθ
T
J MAX
P
T
(
T
JA
JA
JA
D MAX
A
J
T
(
J RISE
(
)
=
=
=
=
=
=
=
=
=
=
=
=
=
=
T
=
)
J
=
P
)
=
Maximum continuous junction
temperature
Total device power dissipation
Thermal resistance from
junction to ambient
Maximum ambient temperature
Maximum device power
dissipation
Maximum continuous junction
temperature
Maximum ambient temperature
Thermal resistance from
junction to ambient
Rise in device junction
temperature over the ambient
temperature
Maximum device power
dissipation
Thermal resistance from
junction to ambient
Junction Temperature
Rise in device junction
temperature over the ambient
temperature
Ambient temperature
TOTAL
=
(
---------------------------------------------------
T
T
P
J RISE
© 2008 Microchip Technology Inc.
J MAX
(
(
D MAX
(
×
Rθ
Rθ
)
)
+
–
)
JA
JA
×
T
T
A
A MAX
Rθ
+
(
T
JA
AMAX
)
)