VN5E050J-E Datasheet, PDF (24/34 Pages) STMicroelectronics – Single channel high side driver for automotive applications

Application information
VN5E050J-E
3.4
Open load detection in Off state
Off-state open-load detection requires an external pull-up resistor (R_PU) connected between
the OUTPUT pin and a positive supply voltage (V_PU) like the +5V line used to supply the
microprocessor.
The external resistor has to be selected according to the following requirements:
1. No false open load indication when load is connected: in this case we have to avoid
V_OUT to be higher than V_Olmin; this results in the following condition
V_OUT= (V_PU/(R_L+R_PU))R_L<V_Olmin.
2. No misdetection when load is disconnected: in this case the V_OUT has to be higher than
V_OLmax; this results in the following condition R_PU<(V_PU–V_OLmax)/I_L(off2).
Because I_s(OFF) may significantly increase if V_out is pulled high (up to several mA), the pull-
up resistor R_PU should be connected to a supply that is switched OFF when the module is in
standby.
The values of V_OLmin, V_OLmax and I_L(off2) are available in the Electrical characteristics
section.
Figure 33. Open load detection in Off state
V batt.
VPU
VCC
R PU
INP UT
DRIVER
+
LOGIC
IL(off2)
S TATU S
+
R
-
OUT
VOL
RL
GROUND
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