MIC2005-0.5LYM5 TR Micrel Inc, MIC2005-0.5LYM5 TR Datasheet - Page 28

• Manufacturer Part Number: MIC2005-0.5LYM5 TR
• Description: Fixed Current Limit Single High-Side Switch + Flag + Cslew, Active Low- 0.5A -
• Manufacturer: Micrel Inc
• Type: High Side Switchr

Specifications of MIC2005-0.5LYM5 TR

• Number Of Outputs: 1
• Rds (on): 100 mOhm
• Internal Switch(s): Yes
• Current Limit: 500mA
• Voltage - Input: 2.5 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-5, SC-74A, SOT-25
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 576-3397-2

August 2011
Power Dissipation
Power dissipation depends on several factors such as
the load, PCB layout, ambient temperature, and supply
voltage. Calculation of power dissipation can be
accomplished by the following equation:
To relate this to junction temperature, the following
equation can be used:
where:
T
T
R
In normal operation the switch’s R
no significant I
most often caused by a short circuit, or very-heavy
load, when a significant portion of the input supply
voltage appears across the switch’s power MOSFET.
Under these conditions the heat generated will exceed
the package and PCB’s ability to cool the device and
thermal limiting will be invoked.
T
Micrel, Inc.
J
A
J
θ(J-A)
= junction temperature
= ambient temperature
=
P
D
is the thermal resistance of the package
P
×
D
R
=
θ
J (
R
−
DS
A
)
2
(
R heating occurs. Device heating is
+
ON
T
)
A
×
I (
OUT
)
2
ON
is low enough that
28
In Figure 12, die temperature is plotted against I
assuming a constant case temperature of 85°C. The
plots also assume a worst case R
temperature of 135°C. Under these conditions it is clear
that an SOT-23 packaged device will be on the verge of
thermal shutdown, typically 140°C die temperature,
when operating at a load current of 1.25A. For this
reason we recommend using MLF
for any design intending to supply continuous currents
of 1A or more.
Figure 12. Die Temperature vs. I
160
140
120
100
80
60
40
20
Output Current (T
0
0.2
0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0
Die Temperature vs.
OUTPUT CURRENT (A)
SOT-23
CASE
MLF
ON
®
=85°C)
packaged switches
of 140mΩ at a die
MIC20xx Family
M9999-080211-D
OUT
OUT