VNF9Q20F datasheet(2/109 Pages) STMICROELECTRONICS

2 / 109 page

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 4 outputs controllable via SPI or 2-OTP assignable direct inputs. 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 VNF9Q20F 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 VNF9Q20F 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 4 outputs can be directly controlled by dedicated,

assignable direct inputs.

It is also possible to configure the VNF9Q20F in parallel mode (CH0//CH1 only) through a dedicated OTP bit.

The VNF9Q20F 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.

VNF9Q20F

DS13909 - Rev 6

page 2/109

VNF9Q20F Datasheet(PDF) 2 Page - STMicroelectronics