STEF12PUR STMicroelectronics, STEF12PUR Datasheet - Page 7

• Manufacturer Part Number: STEF12PUR
• Description: IC LINEAR VOLTAGE REG 10VDFPN
• Manufacturer: STMicroelectronics

Specifications of STEF12PUR

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 497-11266-2

STEF12
4.1
4.1.1
4.1.2
4.1.3
4.1.4
4.1.5
4.2
Operating modes
Turn-on.
When the input voltage is applied, the Enable/Fault pin goes up to the high state, enabling
the internal control circuitry.
After an initial delay time of typically 350 s, the output voltage is supplied with a slope
defined by the internal dv/dt circuitry. If no additional capacitor is connected to dv/dt pin, the
total time from the Enable signal going high and the output voltage reaching the nominal
value is around 1ms (refer to
Normal operating condition.
The STEF12 E-fuse behaves like a mechanical fuse, buffering the circuitry on its output with
the same voltage shown at its input, with a small voltage fall due to the N-channel MOSFET
RDSOn.
Output voltage clamp.
This internal protection circuit clamps the output voltage to a maximum safe value, typically
15V, if the input voltage exceeds this threshold.
Current Limiting.
When an overload event occurs, the current limiting circuit reduces the conductivity of the
power MOSFET, in order to clamp the output current at the value selected externally by
means of the limiting resistor R
Thermal Shutdown.
If the device temperature exceeds the thermal latch threshold, typically 165°C, the thermal
shutdown circuitry turns the power MOSFET off, thus disconnecting the load. The EN/Fault
pin of the device will be automatically set at an intermediate voltage, in order to signal the
overtemperature event. In this condition the E-fuse can be resetted either by cycling the
supply voltage or by pulling down the EN pin below the V
R limit calculation
As shown in
monitor the output current and limit it at the level set by the user.
The R
following theoretical formula, together with the
Limit
value for achieving the requested current limitation can be extimated by using the
Figure
2, the device uses an internal N-channel Sense Fet with a fixed ratio, to
Figures 4,
Doc Number Rev 07
R
Limit
Limit
(Figure
=
------------- -
I
14)
Short
95
2).
“Current limit vs R
il
threshold and then releasing it.
Limit
„,
Typical Application
graph in
Figure
7/17
10.