Datasheet

36 NXP Semiconductors
10XS3435
7.3.3.2 Openload faults
The 10XS3435 incorporates three dedicated openload detection circuitries on the output to detect in OFF and in ON state.
7.3.3.3 Openload detection In OFF state
The OFF output openload fault is detected when the output voltage is higher than V
OLD(THRES)
pulled up with internal current source
(
I
OLD(OFF)
) and reported as a fault condition when the output is disabled (OFF). The OFF Output openload fault is latched into the status
register or when the internal gate voltage is pulled low enough to turn OFF the output. The OL_OFF[0:3] fault bit is set in the status register.
If the open load fault is removed (
FS output pin goes to high), the status register will be cleared after reading the register.
The OFF output openload protection can be disabled through SPI (OLOFF_DIS[0:3] bit).
7.3.3.4 Openload detection in ON state
The ON output openload current thresholds can be chosen by SPI to detect a standard bulbs or LEDs (OLLED[0:3] bit set to logic [1]). In
the case where load current drops below the defined current threshold OLON bit is set to logic [1], the output stays ON and FS
is not
disturbed.
7.3.3.5 Openload detection in ON state for LED
Open load for LEDs only (OLLED[0:3] set to logic [1]) is detected periodically each t
OLLED
(fully-on, D[7:0] = FF). To detect OLLED in fully-
on state, the output must be ON at least t
OLLED.
and PWM module must be enabled (PWM_en = 1 in GCR register)
To delatch the diagnosis, the condition should be removed and SPI read operation is needed (OL_ON[0:3] bit). The ON output openload
protection can be disabled through SPI (OLON_DIS[0:3] bit).
7.3.4 Analog current recopy and temperature feedback
The CSNS pin is an analog output reporting a current proportional to the designed output current or a voltage proportional to the
temperature of the GND flag (pin #14). The routing is SPI programmable (TEMP_en, CSNS_en, CSNS_s[1,0] and CSNS_ratio_s bits).
In case the current recopy is active, the CSNS output delivers current only during ON time of the output switch without overshoot. The
maximum current is 2.0 mA typical. The typical value of external CSNS resistor connected to the ground is 2.5 kOhm.
The current recopy is not active in Fail-safe mode.
7.3.4.1 Temperature prewarning detection
In Normal mode, the 10XS3435 provides a temperature prewarning reported via SPI in case of the temperature of the GND flag is higher
than T
OTWAR
. This diagnosis (OTW bit set to [1]) is latched in the SPI DIAGR0 register. To delatch, a read SPI command is needed.
7.3.5 Active clamp on VPWR
The device provides an active gate clamp circuit in order to limit the maximum transient VPWR voltage at VPWR
(CLAMP)
. In case of
overload on an output the corresponding output is turned off which leads to high voltage at VPWR with an inductive VPWR line. When the
VPWR voltage exceeds VPWR
(CLAMP)
threshold, the turn-off on the corresponding output is deactivated and all HS[0:3] outputs are
switched ON automatically to demagnetize the inductive Battery line.
For a long battery line between the battery and the device (> 20 meters), the smart high-side switch output may exceed the energy
capability in case of a short-circuit. It is recommended to implement a voltage transient suppressor to drain the battery line energy.
7.3.6 Reverse battery on VPWR
The output survives the application of reverse voltage as low as -18 V. Under these conditions, the ON resistance of the output is two
times higher than typical ohmic value in forward mode. No additional passive components are required except on VDD current path.