STBP110 Datasheet, PDF (7/40 Pages) STMicroelectronics – Overvoltage protection device

STBP110
2
Pin description
Pin description
2.1
Input (IN)
Input voltage (IN) pin. The IN pin is connected to the DC power supply. An external low ESR
ceramic capacitor of minimum value 1 µF must be connected between IN and GND. This
capacitor is needed for decoupling and also protects the IC against fast voltage spikes and
ESD events. This capacitor should be located as close to the IN pin as possible.
2.2
Output (OUT)
Output voltage (OUT) pin. The OUT pin is connected to the input through a low R_DS(on)
N-channel MOSFET switch.
If no fault is detected and the STBP110 is enabled by the EN input, this switch is turned on
and the output voltage follows the input voltage.
The output is disconnected from the input when the input voltage is under the UVLO
threshold or above the OVLO threshold, when the junction temperature is above the thermal
shutdown threshold or when the device is disabled by the EN input.
After the input voltage or junction temperature returns to the specified range, there is
a recovery delay, t_rec, and the power output is then connected to the input (see Figure 8).
The switch turn-on time is intentionally prolonged to limit the inrush current and voltage drop
caused, for example, by charging output capacitors (soft-start feature).
2.3
Fault indication output (FLT)
The active low, open-drain fault indication output provides information on the STBP110 state
to the application controller. The FLT is asserted (i.e. driven low), if the STBP110 is in the
overvoltage condition or thermal shutdown mode is active.
As the FLT output is of the open-drain type, it may be pulled up by an external resistor R_PU
to the controller supply voltage (see Figure 4). If there is no need to use this output, it may
be left disconnected. The suitable R_PU resistor value is in the range of 10 kΩ to 1 MΩ.
To improve safety and to prevent damage to application circuits in the event of extreme
voltage or current conditions, an optional protective resistor R_FLT can be connected between
the FLT output and the controller input (see Figure 4). The suitable R_FLT resistor value is in
the range of 10 kΩ to 100 kΩ.
The FLT output is in Hi-Z (high impedance) state when the device is disabled by EN input or
when the input voltage is lower than the UVLO threshold.
2.4
Enable input (EN)
This active low logical input can be used to enable or disable the device. When the EN input
is driven high, the STBP110 is in shutdown mode and the power output is disconnected
from the input (see Figure 8). When the EN input is driven low and all operating conditions
are within specified limits, the power output is connected to the input.
Doc ID 018687 Rev 3
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