Datasheet

Smart shutdown function L6390
14/26 Doc ID 14493 Rev 7
7 Smart shutdown function
The L6390 integrates a comparator committed to the fault sensing function. The comparator
has an internal voltage reference V
ref
connected to the inverting input, while the non-
inverting input is available on pin 10. The comparator input can be connected to an external
shunt resistor in order to implement a simple overcurrent detection function. The output
signal of the comparator is fed to an integrated MOSFET with the open drain output
available on pin 2, shared with the SD input. When the comparator triggers, the device is set
in shutdown state and both its outputs are set to low level leaving the half-bridge in tri-state.
Figure 6. Smart shutdown timing waveforms
SD/OD
FROM/TO
CONTROLLER
V
BIAS
C SD
RSD
SMART
SD
LOGIC
RON_OD
SHUT DOWN CIRCUIT
RPD_SD
An approximation of the disable time is given by:
where:
HIN/LIN
HVG/LVG
open drain gate
(internal)
comp Vref
CP+
PROTECTION
Fast shut down:
the driver outputs are set in SD state immediately after the comparator
triggering even if the SD signal has not yet reach the lower input threshold
disable time
SD/OD
AM12947v1