MIC2005-1.2YM6 TR Micrel Inc, MIC2005-1.2YM6 TR Datasheet - Page 11

• Manufacturer Part Number: MIC2005-1.2YM6 TR
• Description: IC DISTRIBUTION SW 1.2A SOT23-6
• Manufacturer: Micrel Inc
• Type: High Side Switchr

Specifications of MIC2005-1.2YM6 TR

• Number Of Outputs: 1
• Rds (on): 100 mOhm
• Internal Switch(s): Yes
• Current Limit: 1.2A
• Voltage - Input: 2.5 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: SOT-23-6
• Short Circuit Current Limit: 1.6A
• Input Voltage Range: 2.5 to 5.5V
• Number Of Switches: Single
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 6
• Package Type: SOT-23
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 576-2589-2; MIC2005-1.2YM6 TR; MIC2005-1.2YM6TR; MIC2005-1.2YM6TR

January 2008
Functional Description
VIN and VOUT
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 (~0.6V), while the switch is
disabled, current will flow from output to input via the
power MOSFET’s body diode. This effect can be used
to advantage when large bypass capacitors are placed
on MIC2005/2015’s output. When power to the switch is
removed, the output capacitor will be automatically
discharged.
If discharging C
consider using MIC2005/2015 or MIC2007/2017 in place
of MIC2005/2015. These MIC2000 family members are
equipped with a discharge FET to insure complete
discharge of C
Current Sensing and Limiting
MIC2005/2015 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 an internally 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 MIC2005/2015 goes into thermal shutdown.
Kickstart (MIC2015 only)
The MIC2015 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 MIC2015 differs markedly
from MIC2005 and its peers, which immediately limit
load current, potentially starving the motor and causing
the appliance to stall or stutter.
During this delay period, typically 128 ms, a secondary
current limit is in effect. If the load demands a current in
excess the secondary limit, MIC2015 acts immediately
to restrict output current to the secondary limit for the
IN
IN
is both the power supply connection for the internal
to V
OUT
toward the load. Since the switch is bi-
LOAD
LOAD
.
is required by your application,
OUT
to V
IN
OUT
.
is greater than V
OUT
exceed V
OUT
is the
IN
by
IN
,
11
duration of the Kickstart period. After this time the
MIC2015 reverts to its normal current limit. An example
of Kickstart operation is shown below.
A) MIC2015 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
Under Voltage Lock Out
Under voltage lock-out insures no anomalous operation
occurs before the device’s minimum input voltage of
2.5V 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.
Picture Key:
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).
MIC2015 drops out of current limiting.
HIGH.
O
O
U
OUT
ON
U
T
T
of the power FET increases due to internal
is non-zero (load is heavy, but not a dead short
Figure 3. Kickstart Operation
OUT
= 0. Limiting response will be the same
M9999-011708-A
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