MCP1701T-1802I/CB Microchip Technology, MCP1701T-1802I/CB Datasheet - Page 11
MCP1701T-1802I/CB
Manufacturer Part Number
MCP1701T-1802I/CB
Description
IC LDO REG 110MA 1.8V SOT-23A
Manufacturer
Microchip Technology
Datasheet
1.MCP1701-1802ITO.pdf
(20 pages)
Specifications of MCP1701T-1802I/CB
Regulator Topology
Positive Fixed
Voltage - Output
1.8V
Voltage - Input
Up to 10V
Voltage - Dropout (typical)
0.18V @ 20mA
Number Of Regulators
1
Current - Output
110mA (Min)
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
SOT-23A-3
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Current - Limit (min)
-
Other names
MCP1701T-1802I/CB
MCP1701T1802ICBRTR
MCP1701T1802ICBRTR
MCP1701T1802ICBTR
MCP1701T1802ICBRTR
MCP1701T1802ICBRTR
MCP1701T1802ICBTR
5.0
5.1
The amount of power dissipated internal to the LDO
linear regulator is the sum of the power dissipation
within the linear pass device (P-channel MOSFET) and
the quiescent current required to bias the internal
reference and error amplifier. The internal linear pass
device power dissipation is calculated as shown in
Equation 5-1.
EQUATION 5-1:
The internal power dissipation, as a result of the bias
current for the LDO internal reference and error
amplifier, is calculated as shown in Equation 5-2.
EQUATION 5-2:
The total internal power dissipation is the sum of P
(pass device) and P
EQUATION 5-3:
For the MCP1701, the internal quiescent bias current is
so low (2 µA, typ.) that the P
dissipation equation can be ignored. The maximum
power dissipation can be estimated by using the
maximum input voltage and the minimum output
voltage to obtain a maximum voltage differential
between input and output. The next step would be to
multiply the maximum voltage differential by the
maximum output current.
EQUATION 5-4:
© 2005 Microchip Technology Inc.
Given:
T
P
P
V
AMAX
I
MAX
MAX
OUT
OUT
V
IN
P
TOTAL
THERMAL CONSIDERATIONS
Power Dissipation
P
P
D
= 3.3V to 4.1V
= 3.0V ± 2%
= 1 mA to 100 mA
= 55°C
= (4.1V – (3.0V x 0.98)) x 100 mA
= 116.0 milliwatts
D
(Pass Device) = (V
= (V
= P
P
INMAX
D
D
(Pass Device) + P
(Bias) = V
D
(bias).
– V
OUTMIN
D
IN
IN
(bias) term of the power
– V
x I
) x I
GND
OUT
D
OUTMAX
(Bias)
) x I
OUT
D
To determine the junction temperature of the device, the
thermal resistance from junction-to-ambient must be
known. The 3-pin SOT-23 thermal resistance from
junction-to-air (R
335° C/W. The SOT-89 R
approximately 52° C/W when mounted on 1 square inch
of copper. The R
and other application-specific conditions.
The device junction temperature is determined by
calculating the junction temperature rise above
ambient, then adding the rise to the ambient
temperature.
EQUATION 5-5:
EQUATION 5-6:
T
T
T
T
T
J
J
J
J
J
=
=
=
=
=
P
116.0 milliwatts 335°C/W
93.9°C
116.0 milliwatts 52°C/W
61°C
DMAX
JA
JA
will vary with physical layout, airflow
) is estimated to be approximately
JUNCTION
TEMPERATURE – SOT-23
EXAMPLE:
JUNCTION
TEMPERATURE – SOT-89
EXAMPLE:
R
JA
+
MCP1701
T
JA
A
is estimated to be
DS21874B-page 11
+
+
55°C
55°C