STEF033 Datasheet, PDF (11/25 Pages) STMicroelectronics – Electronic fuse for 3.3 V line

STEF033
Typical application
5.3
C_dv/dt calculation
The device includes a rise-time control circuit, allowing the soft-start during turn-on and Hot-
plug of the equipment. The pre-programmed rise time, defined as the time interval during
which the output voltage goes from 10% to 90% of the nominal voltage, is typically 1.4 ms.
The STEF033 and STEF033A in DFN10 package feature a user-programmable output
voltage ramp-up time; by connecting a capacitor between the C_dv/dt pin and GND,
modification of the output voltage ramp-up time is possible. The capacitance to be added on
the C_dv/dt pin can be selected using the following table.
Table 7. Typical rise time values vs. dv/dt capacitor
C_dv/dt
Rise Time ⁽¹⁾ [ms]
none
1.4
100 pF
2.8
470 pF
8
1. V_CC = 3.3 V, C_IN = 10 µF, C_OUT = 10 µF, R_LIMIT = 24 Ω, I_OUT = 1 A
1 nF
16
Figure 5. Delay time and V_OUT rise time
90%
delay
time
10%
rise
time
V_OUT
Enable
5.4
Enable-Fault pin
The Enable/Fault pin has the dual function of controlling the output of the device and, at the
same time, of providing information about the device status to the application.
It can be connected to an external open-drain or open-collector device. In this case, when it
is pulled at low logic level, it will turn the output of the E-Fuse off.
If this pin is left floating, since it has internal pull-up circuitry, the output of the E-Fuse is kept
ON in normal operating conditions.
This pin should never be biased to a voltage higher than 3.6 V.
In case of thermal fault, the pin is pulled to an intermediate state (Figure 6). This signal can
be provided to a monitor circuit, signaling that a thermal shutdown has occurred, or it can be
DocID025099 Rev 2
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