MIC2583R-MBQS TR Micrel Inc, MIC2583R-MBQS TR Datasheet - Page 18

• Manufacturer Part Number: MIC2583R-MBQS TR
• Description: IC CTRLR HOT SWAP 200MV 16-QSOP
• Manufacturer: Micrel Inc
• Type: Hot-Swap Controllerr

Specifications of MIC2583R-MBQS TR

• Applications: General Purpose
• Internal Switch(s): No
• Voltage - Supply: 2.3 V ~ 13.2 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP (0.150", 3.90mm Width)
• Linear Misc Type: Positive Low Voltage
• Family Name: MIC2583
• Package Type: QSOP
• Operating Supply Voltage (min): 2.3V
• Operating Supply Voltage (max): 13.2V
• Operating Temperature (min): -40C
• Operating Temperature (max): 85C
• Operating Temperature Classification: Industrial
• Product Depth (mm): 3.99mm
• Product Height (mm): 1.4mm
• Product Length (mm): 4.98mm
• Mounting: Surface Mount
• Pin Count: 16
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: MIC2583R-MBQSTR; MIC2583R-MBQSTR

For
considerations, please see MOSFET Selection text and
subsequent sections.
Auto-Restart - MIC2583R
The MIC2583R provides an auto-restart function. Upon
an overcurrent fault condition such as a short circuit, the
MIC2583R initially shuts off the GATE output. The
MIC2583R attempts to restart with a 12µA charge
current at a preset 10% duty cycle until the fault
condition is removed. The interval between auto-retry
attempts is set by capacitor C
Sense Resistor Selection
The MIC2582 and MIC2583 use a low-value sense
resistor to measure the current flowing through the
MOSFET switch (and therefore the load). This sense
resistor is nominally set at 50mV/I
accommodate worst-case tolerances for both the sense
resistor (allow ±3% over time and temperature for a
resistor with ±1% initial tolerance) and still supply the
maximum required steady-state load current, a slightly
more detailed calculation must be used.
The current limit threshold voltage (i.e., the “trip point”)
for the MIC2582/83 may be as low as 42mV, which
would
42mV/I
case where the value of the sense resistor is 3% high
yields:
Micrel, Inc.
April 2009
additional
LOAD(CONT)
equate
. Carrying the numbers through for the
information
to
a
sense
FILTER
on
.
resistor
MOSFET
Figure 8. 5V Switch/3.3V LDO Application
LOAD(CONT)
value
thermal
. To
of
18
Once the value of R
manner, it is good practice to check the maximum
I
tolerance buildup in the opposite direction. Here, the
worst-case maximum current is found using a 59mV trip
voltage and a sense resistor that is 3% low in value. The
resulting equation is:
As an example, if an output must carry a continuous 2A
without nuisance trips occurring, Equation 11
yields:
lowest standard value is 20mΩ. At the other set of
tolerance extremes for the output in question,
Knowing this final data, we can determine the necessary
wattage of the sense resistor using P = I
be I
These numbers yield the following: P
(19.4mΩ) = 0.175W.
In this example, a
R
I
I
LOAD(CONT)
LOAD
LOAD
SENSE
LOAD(CONT, MAX)
(
(
CONT
CONT
R
(
MAX
SENSE
which the circuit may let through in the case of
,
,
MAX
MAX
)
=
(
)
)
MAX
(
. 1
=
=
, and R will be (0.97)(R
03
¼
(
60
20
)
. 0
W sense resistor is sufficient.
=
)
8 .
0 .
(
97
42
I
LOAD
40
mV
m
SENSE
)
mV
(
Ω
R
59
8 .
2
SENSE
A
(
mV
CONT
=
mV
. 3
has been chosen in this
04
=
)
(
NOM
)
20
A
=
,
4 .
I
)
MIC2582/MIC2583
MAX
approximately 3A.
LOAD
)
40
m
=
M9999-043009-C
Ω
SENSE(NOM)
2
= (3A)
8 .
R, where I will
R
.
(
CONT
mV
SENSE
The next
60
8 .
2
)
mV
(
NOM
).
(11)
)
(1 2 )