MLX83202 Datasheet, PDF (16/35 Pages) Melexis Microelectronic Systems – Automotive NFET pre-drivers

MLX83202/MLX83203
Automotive NFET pre-drivers
8.3 Enable input
Pulling the Enable input (EN) low forces the pre-driver to pull all FET gate voltages to ground, switching off all
external transistors (high impedance). While EN is low, the programming of the EEPROM via SPI can be
initiated by pulling ICOM low for a time Tspi_su.
8.4 Protection and diagnostic functions
8.4.1 Drain-source voltage monitoring
The MLX8320x provides a drain-source voltage monitoring feature for each external FET to protect against
short circuits. This drain-source voltage monitoring comparator can be enabled/disabled in EEPROM.
The drain-source voltage monitor for a certain external FET is only active when the corresponding input is set
to “on” and the dead time is over. An additional blanking time can be programmed in EEPROM. If the drain-
source voltage stays higher than the VDS monitor threshold voltage, the VDS error is raised. This threshold
voltage is configurable in EEPROM.
The reaction of the pre-driver on a VDS error can be configured in EEPROM with the Bridge Feedback bit. If
this bit is set the pre-driver will automatically disable the drivers when a VDS error is detected. If not set the
pre-driver remains active. In any case the VDS error will be reported.
VDS_COMP_EN
0
1
VDS_BF_EN
x
0
Pre-driver reaction on error event
Any drain-source over voltage event is ignored
and no error is reported on ICOM.
VDS_ERR is reported on ICOM, but the pre-driver remains active.
1
1
VDS_ERR is reported on ICOM and the pre-driver is disabled.
Table 6. Pre-driver reaction on VDS error
8.4.2 Programmable dead time
The pre-drivers’ internal implementation guarantees that low side and high side of the same external half
bridge can not be “on” at the same time connecting supply directly to ground. See Figure 12 for this internal
implementation of the pre-driver. The pre-driver also provides a programmable dead time in EEPROM.
8.4.3 Supply overvoltage shutdown
The pre-driver has an integrated VSUP over voltage shut down to prevent destruction of the pre-driver at high
supply voltages. A VSUP_OV event will always switch off the pre-driver, this reaction can not be masked.
8.4.4 Regulated supply overvoltage shutdown
The pre-driver has an integrated VREG over voltage shut down. The reaction of the pre-driver on this
VREG_OV depends on the status of the Bridge Feedback bit in EEPROM. If this VREG_OV_BF_EN bit is set
the pre-driver will pull all gate voltages low, switching off all external FETs.
3901083203
Rev 2.2
Page 16 of 35
Prelim. Data Sheet
4 Dec 2013