NCV8460A Datasheet, PDF (14/16 Pages) ON Semiconductor – Self Protected High Side Driver with Temperature Shutdown and Current Limit

5V
STAT
Input
NCV8460A
Vbat
GND
V pull −up
VD
V OUT
OL I
R pull −up
RL
Figure 32. Open Load Detection In Off State
OFF State Open Load Detection
Off State Open Load Detection requires an external
pull-up resistor (R_pull-up) connected between V_OUT pin and
a positive supply voltage (V_pull-up).
The external R_pull-up resistor value should be selected to
ensure that a false OFF State OL condition is not detected
when the load (R_L) is connected. A V_OUT voltage above the
V_{OL_min} (Openload Off State Detection Threshold)
minimum value with the load (R_L) connected needs to be
avoided. The following formula shows this relationship:
ǒ ǒ ǓǓ _{VOUT + Vpull*upń RL ) Rpull*up RL t VOL_min}
In addition to ensuring the selected R_pull-up resistor value
does not cause a false OFF State OL detection condition
when the load is connected, the R_pull-up must also not cause
the OFF State OL to miss detecting an OL condition when
the load is disconnected. A V_OUT voltage below the
V_{OL_max} (Openload Off State Detection Threshold)
maximum value with the load (R_L) disconnected needs to be
avoided. The following formula shows this relationship:
ǒ Ǔ _{Rpull*up t Vpull*up * VOL_max ńOL1}
OL₁ + I_L^ǒOutput Leakage with V_OUT + 3.5 V^Ǔ
Because I_d (OFF) may significantly increase if V_OUT is
pulled high (up to several mA), R_pull-up resistor should be
connected to a supply that is switched OFF when the module
is in standby.
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