MIC39100-1.8BS Micrel Inc, MIC39100-1.8BS Datasheet - Page 11

• Manufacturer Part Number: MIC39100-1.8BS
• Description: IC REG LDO 1A 1.8V SOT223
• Manufacturer: Micrel Inc

Specifications of MIC39100-1.8BS

• Mounting Type: Surface Mount
• Regulator Topology: Positive Fixed
• Voltage - Output: 1.8V
• Voltage - Input: 2.25 ~ 16 V
• Voltage - Dropout (typical): 0.41V @ 1A
• Number Of Regulators: 1
• Current - Output: 1A (Min)
• Operating Temperature: -40°C ~ 125°C
• Package / Case: SOT-223 (3 leads + Tab), SC-73, TO-261
• No. Of Pins: 3
• Peak Reflow Compatible (260 C): No
• Supply Voltage: 60V
• Output Voltage: 1.8V
• Current Rating: 1A
• Output Voltage Max: 1.8V
• Leaded Process Compatible: No
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Limit (min): -
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant, Lead free / RoHS Compliant

For example, the maximum ambient temperature is 50°C,
the ΔT is determined as follows:
Using Figure 4, the minimum amount of required copper can
be determined based on the required power dissipation. Power
dissipation in a linear regulator is calculated as follows:
If we use a 2.5V output device and a 3.3V input at an output
current of 1A, then our power dissipation is as follows:
From Figure 4, the minimum amount of copper required to
operate this application at a ΔT of 75°C is 160mm
August 2005
MIC39100/39101/39102
ΔT = T
T
T
ΔT = 125°C – 50°C
ΔT = 75°C
P
P
P
P
A(max)
J(max)
D
D
D
D
= (V
= (3.3V – 2.5V) × 1A + 3.3V × 11mA
= 800mW + 36mW
= 836mW
J(max)
= 125°C
= maximum ambient operating temperature
IN
– V
– T
OUT
A(max)
) I
OUT
+ V
IN
· I
GND
2
.
11
Quick Method
Determine the power dissipation requirements for the design
along with the maximum ambient temperature at which the
device will be operated. Refer to Figure 5, which shows safe
operating curves for three different ambient temperatures:
25°C, 50°C and 85°C. From these curves, the minimum
amount of copper can be determined by knowing the maxi-
mum power dissipation required. If the maximum ambient
temperature is 50°C and the power dissipation is as above,
836mW, the curve in Figure 5 shows that the required area
of copper is 160mm
The θ
depending upon the availability of copper ground plane to
which it is attached.
JA
of this package is ideally 63°C/W, but it will vary
2
.
M9999-082505-B
Micrel