TC2055-2.85VCTTR Microchip Technology, TC2055-2.85VCTTR Datasheet - Page 5

• Manufacturer Part Number: TC2055-2.85VCTTR
• Description: IC CMOS LDO 2.85V 100MA SOT23A-5
• Manufacturer: Microchip Technology

Specifications of TC2055-2.85VCTTR

• Regulator Topology: Positive Fixed
• Voltage - Output: 2.85V
• Voltage - Input: Up to 6V
• Voltage - Dropout (typical): 0.09V @ 100mA
• Number Of Regulators: 1
• Current - Output: 100mA (Min)
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-5, SC-74A, SOT-25
• Number Of Outputs: 1
• Polarity: Positive
• Input Voltage Max: 6 V
• Output Voltage: 2.85 V
• Output Type: Fixed
• Dropout Voltage (max): 140 mV
• Output Current: 100 mA
• Line Regulation: 0.05 %
• Load Regulation: 0.5 %
• Voltage Regulation Accuracy: 0.4 %
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Limit (min): -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: TC20552.85VCTTR

4.0
4.1
The amount of power the regulator dissipates is prima-
rily a function of input and output voltage, and output
current.
The following equation is used to calculate worst case
power dissipation:
EQUATION 4-1:
The maximum allowable power dissipation (Equation
4-2) is a function of the maximum ambient temperature
(T
°C) and the thermal resistance from junction-to-air
(θ
approximately 220°C/Watt when mounted on a typical
two layer FR4 dielectric copper clad PC board.
EQUATION 4-2:
©
P
Where:
Where all terms are previously defined
P
V
V
I
JA
A MAX
2002 Microchip Technology Inc.
D
LOAD MAX
D
IN MAX
OUT MIN
). The 5-Pin SOT-23A package has a θ
≈ (V
), the maximum allowable die temperature (125
IN
THERMAL CONSIDERATIONS
Power Dissipation
– V
=
=
=
=
OUT MIN
P
Worst case actual power dissipation
Maximum voltage on V
Minimum regulator output voltage
Maximum output (load) current
D
M A X
)I
=
LOAD MAX
T
---------------------------------- -
J
M AX
θ
–
JA
T
A
M A X
IN
JA
of
Equation 4-1 can be used in conjunction with Equation
4-2 to ensure regulator thermal operation is within lim-
its. For example:
Maximum allowable power dissipation:
In this example, the TC2054 dissipates a maximum of
only 20.7mW; far below the allowable limit of 318mW.
In a similar manner, Equation 4-1 and Equation 4-2 can
be used to calculate maximum current and/or input
voltage limits.
4.2
The primary path of heat conduction out of the package
is via the package leads. Therefore, layouts having a
ground plane, wide traces at the pads, and wide power
supply bus lines combine to lower θ
increase the maximum allowable power dissipation
limit.
Given:
Find
:
Actual power dissipation:
V
V
I
T
1. Actual power dissapation
2. Maximum allowable dissapation
P
TC2054/2055/2186
LOAD MAX
A MAX
IN MAX
OUT MIN
D
Layout Considerations
P
D
= 3.0V ±5%
= 2.7V – 2.5%
= 40mA
= 55°C
≈ (V
= [(3.0 x 1.05) – (2.7 x .975)]40 x 10
= 20.7mW
M A X
=
= 318mW
IN MAX
(
-------------------------- -
125 55
(
------------------------------------- -
T
220
J
M AX
–
– V
θ
–
JA
OUT MIN
T
)
A
M A X
JA
DS21663B-page 5
)
and, therefore,
)I
LOAD MAX
–3