MIC2007 Datasheet, PDF (12/17 Pages) Micrel Semiconductor – Adjustable Current Limit Power Distribution Switch

Micrel
MIC2007/MIC2017
Enable
ENABLE is a HIGH true control signal, which activates
the main MOSFET switch. ENABLE will operate with
logic running from supply voltages as low as 1.8V, once
V_IN has exceeded the UVLO threshold. ENABLE can be
wire-OR’d with other MIC2007/2017s or similar devices
without damage to the device.
ENABLE may be driven higher than V_IN, but no higher
than 5.5V.
Slew Rate Control
Large capacitive loads can create significant current
surges when charged through a high-side switch such
as the MIC2007/2017. For this reason, the
MIC2007/2017 provides built-in slew rate control to limit
the initial inrush currents upon enabling the power
MOSFET switch.
Slew rate control is active upon powering up, and upon
re-enabling the load. At shutdown, the discharge slew
rate is controlled by the external load and output
capacitor.
On MIC2007/2017 slew rate is adjustable and can be
further reduced by adding an external capacitance
between VIN and the CSLEW pins.
Thermal Shutdown
Thermal shutdown is employed to protect the
MIC2007/2017 from damage should the die temperature
exceed safe operating levels. Thermal shutdown shuts
off the output MOSFET if the die temperature reaches
145°C.
The MIC2007/2017 will automatically resume operation
when the die temperature cools down to 135°C. If
resumed operation results in reheating of the die, then
another shutdown cycle will occur and the
MIC2007/2017 will continue cycling between ON and
OFF states until the offending load has been removed.
Depending upon PCB layout, package type, ambient
temperature, etc., hundreds of milliseconds may elapse
from the incidence of a fault to the output MOSFET
being shut off. This delay is due to thermal time
constants within the system itself. In no event will the
device be damaged due to thermal overload because
die temperature is monitored continuously by on-chip
circuitry.
October 2005
12
M9999-102805