VNF9Q20FTR [STMicroelectronics]

The VNF9Q20F 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 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.

• AEC-Q100 qualified
• General
  • Quad channel with 24-bit ST-SPI for full diagnostic and digital current sense feedback
  • Integrated 10-bit ADC for digital current sense
  • Integrated PWM engine with independent phase shift and frequency generation (for each channel)
  • Programmable Bulb/LED mode for all channels
  • Advanced limp-home functions for robust fail-safe system
  • Very low standby current
  • Optimized electromagnetic emissions
  • Very low electromagnetic susceptibility
  • Control through direct inputs and/or SPI
  • Compliant with European directive 2002/95/EC
  • Capacitive loads charging mode
• Diagnostic functions
  • Digital proportional load current sense
  • Synchronous diagnostic of overload, short to GND and harness protection
  • Asynchronous diagnostic of output shorted to V_CC and OFF-state open-load
  • Built In Self-Test for ADC and harness protection
  • Programmable case overtemperature warning
• Protections
  • Full configurable wire harness protection (STi²Fuse)
  • Load current limitation
  • Self-limiting of fast thermal transients
  • Latch-off or programmable time limited auto restart (power limitation and overtemperature shutdown)
  • Undervoltage shutdown
  • Overvoltage clamp
  • Load dump protected
  • Protection against loss of ground