MIC2005-0.5LYM5 TR Micrel Inc, MIC2005-0.5LYM5 TR Datasheet - Page 21

• 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
Functional Description
V
V
circuitry driving the switch and the input (Source
connection) of the power MOSFET switch. V
Drain connection of the power MOSFET and supplies
power to the load. In a typical circuit, current flows from
V
directional when enabled, if V
current will flow from V
When the switch is disabled, current will not flow to the
load, except for a small unavoidable leakage current of
a few microamps. However, should V
more than a diode drop (~0.6 V), while the switch is
disabled, current will flow from output to input via the
power MOSFET’s body diode.
If discharging C
consider using MIC20X4 or MIC20X7; these MIC20XX
family members are equipped with a discharge FET to
insure complete discharge of C
Current Sensing and Limiting
MIC20XX protects the system power supply and load
from damage by continuously monitoring current
through the on-chip power MOSFET. Load current is
monitored by means of a current mirror in parallel with
the power MOSFET switch. Current limiting is invoked
when the load exceeds the set over-current threshold.
When current limiting is activated the output current is
constrained to the limit value, and remains at this level
until either the load/fault is removed, the load’s current
requirement drops below the limiting value, or the
switch goes into thermal shutdown.
Kickstart™
Only parts in bold have Kickstart™.
(Not available in 5-pin SOT-23 packages)
The MIC201X is designed to allow momentary current
surges (Kickstart™) before the onset of current limiting,
which permits dynamic loads, such as small disk drives
or portable printers to draw the energy needed to
overcome inertial loads without sacrificing system
safety. In this respect, the Kickstart™ parts (MIC201X)
differs
(MIC200X) which immediately limit load current,
potentially starving the motor and causing the appliance
to stall or stutter.
Micrel, Inc.
IN
IN
IN
2003
2013
and V
is both the power supply connection for the internal
to V
markedly
OUT
2004
2014
OUT
toward the load. Since the switch is bi-
2005X
LOAD
2015
from
is required by your application,
OUT
2006
2016
to V
the
IN
LOAD
OUT
.
2007
2017
non-Kickstart™
.
is greater than V
OUT
2008
2018
exceed V
OUT
2009X
2019X
is the
parts
IN
by
IN
,
21
During this delay period, typically 128ms, a secondary
current limit is in effect. If the load demands a current in
excess the secondary limit, MIC201X acts immediately
to restrict output current to the secondary limit for the
duration of the Kickstart™ period. After this time the
MIC201X reverts to its normal current limit. An example
of Kickstart™ operation is shown in Figure 3.
Figure 3 Label Key:
A. MIC201X is enabled into an excessive load (slew
B. R
C. Kickstart™ period.
D. Current limiting initiated. FAULT/ goes LOW.
E. V
F. Thermal shutdown followed by thermal cycling.
G. Excessive load released, normal load remains.
H. FAULT/ delay period followed by FAULT/ going
Undervoltage Lock-Out
Undervoltage lock-out insures no anomalous operation
occurs before the device’s minimum input voltage of
UVLO
and 2.5V maximum had been achieved. Prior to
reaching this voltage, the output switch (power
MOSFET) is OFF and no circuit functions, such as
FAULT/ or ENABLE, are considered to be valid or
operative.
rate limiting not visible at this time scale) The initial
current surge is limited by either the overall circuit
resistance and power supply compliance, or the
secondary current limit, whichever is less.
heating (effect exaggerated for emphasis).
where V
for dead shorts).
MIC201X drops out of current limiting.
HIGH.
OUT
ON
THRESHOLD
of the power FET increases due to internal
is non-zero (load is heavy, but not a dead short
OUT
Figure 3. Kickstart™ Operation
= 0V. Limiting response will be the same
which is 2V minimum, 2.25V typical,
MIC20xx Family
M9999-080211-D