MIC2514 Datasheet, PDF (5/5 Pages) Micrel Semiconductor – IttyBitty™ Integrated High-Side Switch Preliminary Information

MIC2514
Functional Diagram
TTL _CTL
Compatible
Input
THERMAL
SHUTDOWN
IN
+3V to +13.5V
CURRENT
LIMIT
.01Ω
MIC2514
GATE
CONTROL
OUT
Micrel
Functional Description
The MIC2514 is a noninverting 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 de-
creases 10°C.
Current Limit
The current limit is preset internally. The preset level pre-
vents damage to the output MOSFET but allows a typical
current of 1.9A through the output MOSFET for the MIC2514.
This current limit is sufficent 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.
6-22
1997