Application information VNQ5E250AJ-E
26/37 Doc ID 17360 Rev 3
3.4 Current sense and diagnostic
The current sense pin performs a double function (see Figure 33: Current sense and
diagnostic):
●
Current mirror of the load current in normal operation, delivering a current
proportional to the load one according to a known ratio K
X
.
The current I
SENSE
can be easily converted to a voltage V
SENSE
by means of an
external resistor R
SENSE
. Linearity between I
OUT
and V
SENSE
is ensured up to 5V
minimum (see parameter V
SENSE
in Table 9: Current sense (8 V < V
CC
<18V)). The
current sense accuracy depends on the output current (refer to current sense electrical
characteristics Table 9: Current sense (8 V < V
CC
<18V)).
●
Diagnostic flag in fault conditions, delivering a fixed voltage V
SENSEH
up to a
maximum current I
SENSEH
in case of the following fault conditions (refer to Table 11):
– Power limitation activation
– Overtemperature
– Short to V
CC
in off-state
– Open load in off-state with additional external components.
A logic level high on CS_DIS pin sets at the same time all the current sense pins of the
device in a high impedance state, thus disabling the current monitoring and diagnostic
detection. This feature allows multiplexing of the microcontroller analog inputs by sharing of
sense resistance and ADC line among different devices.
Figure 33. Current sense and diagnostic
Main MOSn
41V
OUTn
I
Loff2
R
SENSE
R
PROT
To uC ADC
R
PU
V
PU
Pwr_Lim
V
SENSE
PU_ CMD
Overtemperature
OL OFF
+
-
V
OL
CURRENT
SENSEn
I
OUT
/K
X
I
SENSEH
V
BAT
V
SENSEH
Load
INPUTn
V
CC
GND
CS_ DIS
