MIC2514_08 Datasheet, PDF (5/6 Pages) Micrel Semiconductor – IttyBitty Integrated High-Side Switch

Micrel, Inc.
Functional Diagram
MIC2514
Functional Description
The MIC2514 is a non-inverting high-side switch. A
logic-high control input turns on the output transistor,
and a logic-low turns off the output transistor. Fault
conditions turn off the output transistor.
Control Input
Applying a logic-high input to CTL (control input)
activates the thermal shutdown and gate control circuits.
If there are no fault conditions, the output MOSFET turns
on.
Gate Control
The gate control circuit applies the supply voltage to the
output MOSFET gate, turning it off, or forces the
MOSFET gate below the supply voltage, turning it on, as
determined by CTL and thermal shutdown.
Input and Output
IN (input) is the supply connection to the logic circuitry
and the source of the output MOSFET. OUT (output) is
the drain of the output MOSFET. In a typical circuit;
current flows through the switch from IN to OUT toward
the load.
The output MOSFET has an intrinsic body diode which
will conduct if OUT is forced to a higher voltage than IN.
Thermal Shutdown
Thermal shutdown turns off the output MOSFET if the
die temperature exceeds approximately 170°C. Thermal
shut-down releases the output after the die temperature
decreases 10°C.
Current Limit
The current limit is preset internally. The preset level
prevents damage to the output MOSFET but allows a
typical current of 1.9A through the output MOSFET for
the MIC2514. This current limit is sufficient to protect the
bond wire and the output device from instantaneous high
current. Package thermal ratings and power dissipation
should be considered when determining safe continuous
operating current. Output current is monitored by
sensing the voltage drop across the output MOSFET
source metal resistance.
August 2008
5
M9999-082808-C