The VNF9D5SF is a device made using STMicroelectronics VIPower technology. It is intended for driving resistive or inductive loads directly connected to the ground.
The device is protected against voltage transients on the VCC pin. Programming, control, and diagnostics are implemented via the SPI bus. A digital current sense feedback for each channel is provided through an integrated 10-bit ADC. Dedicated trimming bits allow adjusting the ADC reference current.
The device is equipped with 2 outputs controllable via SPI or 2-OTP assignable direct inputs. In whatever operating situation it is always possible to turn off channels quickly by relevant DIx (FAST_OFF < tDIx_off). Real-time diagnostic is available through the SPI bus (open-load, output short to VCC, overtemperature, communication error, power limitation or latch off). The device detects open-load in OFF-state conditions.
The VNF9D5SF embeds the STMicroelectronics proprietary I²t functionality, featuring an intelligent circuit breaking aimed at protecting PCB traces, connectors and wire harness from overheating, with no impact on load transients like inrush currents and capacitance charging. This function is set by two parameters called INOM and tNOM: there are 3 dedicated bits, per each parameter, to set respectively INOM (nominal current) and tNOM (nominal timing). The I²t curve parameters can be individually set per each channel.
The VNF9D5SF can limit the dissipated power to a safe level up to thermal shutdown intervention. Thermal shutdown can be configured as latched off or programmable time limited auto restart.
The output current limitation protects the device in case of overload.
The device enters a fail-safe mode in case of communication loss with the microcontroller, reset of digital memory or watchdog monitoring time-out event. In fail-safe mode, the 2 outputs can be directly controlled by dedicated, assignable direct inputs.
It is also possible to configure the VNF9D5SF in parallel mode (CH0//CH1) through a dedicated OTP bit.
The VNF9D5SF features an operative condition called capacitive charging mode (CCM), which is available in both fail-safe and normal device states and with channels configured in bulb mode.
During the sleep mode, the device is able to support the parking mode functionality. In case one or more OUTPUT pins are pulled up to battery by an external secondary switch (for instance the L99SP08 which is delivering the requested current to the load) the device offers a very low current consumption (ISOFF2). For further information refer to the application note AN6371 - Interaction of L99SP08 with dual (VNF9DxxSF) and quad (VNF9Q20SF) M09 monolithic eFuses.
