VND5E025AS-E Datasheet, PDF (27/37 Pages) STMicroelectronics – Double channel high-side driver with analog current sense for automotive applications

VND5E025AS-E
Application information
3.4.1
Short to V_CC and off-state open-load detection
Short to V_CC
A short circuit between V_CC and output is indicated by the relevant current sense pin set to
V_SENSEH during the device off-state. Little or no current is delivered by the current sense
during the on-state depending on the nature of the short circuit.
Off-state open-load with external circuitry
Detection of an open-load in off mode requires an external pull-up resistor (R_PU) connecting
the output to a positive supply voltage V_PU.
It is preferable that V_PU is switched off during the module standby mode to avoid an increase
in overall standby current consumption in normal conditions, that is, when the load is
connected.
An external pull-down resistor (R_PD) connected between output and GND is mandatory to
avoid misdetection in case of floating outputs in off-state (see Figure 33: Current sense and
diagnostic).
R_PD must be selected in order to ensure V_OUT < V_OLmin unless pulled up by the external
circuitry:
V_{OUT Pull −up _OFF} = R_PD ⋅ I _{L(off 2) f} < V_{OL min} = 2V
R_PD ≤ 22 KΩ is recommended.
For proper open-load detection in off-state, the external pull-up resistor must be selected
according to the following formula:
V_OUT
Pull −up _ ON
=
R_PD ⋅V_PU
− R_PU ⋅ R_PD ⋅ I _{L(off 2)r}
R_PU + R_PD
> V_OLmax
= 4V
For the values of V_OLmin,V_OLmax, I_L(off2)r and I_L(off2)f see Table 10: Open-load detection
(8 V < VCC < 18 V).
Doc ID 022490 Rev 6
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