General Description
With increasing demand for animation in automotive lighting, LEDs
must be controlled independently. Therefore, LED drivers with
digital interfaces are essential to effectively drive
pixel-controlled lighting applications. In exterior lighting,
multiple lamp functions are typically located on different PCB
boards with off-board wires connected to each other. It is
difficult for a traditional single-ended interface to meet the
strict EMC requirements. By using an industrial-standard CAN
physical layer, the UART-based FlexWire interface of the
TPS929120-Q1 easily accomplishes long distance off-board
communication without impacting EMC.
The TPS929120-Q1 is a 12-channel, 40-V high-side LED driver that
controls the 8-bit output current and 12-bit PWM duty cycles. The
device meets multiple regulation requirements with LED
open-circuit, short-to-ground, and single LED short-circuit
diagnostics. A configurable watchdog also automatically sets
fail-safe states when the MCU connection is lost, and, with
programmable EEPROM, TPS929120-Q1 can flexibly be set for different
application scenarios.
Features
- AEC-Q100-qualified for automotive applications:
- Temperature grade 1: –40°C to +125°C, TA
- Functional Safety-Capable
- Documentation available to aid functional safety system design
- 12-Channel precision high-side current output:
- Supply voltage 4.5 V to 40 V
- Up to 75 mA channel current set by resistor
- 2-Bit global, 6-bit independent current setting
- High current accuracy < ±5% at 5 mA to 75 mA
- High current accuracy < ±10% at 1 mA
- Low voltage drop 500 mV at 50 mA
- 12-Bit independent PWM dimming
- Programmable PWM frequency up to 20 kHz
- Linear and exponential dimming method
- FlexWire control interface
- Up to 1-MHz clock frequency
- Maximum 16 devices on one FlexWire bus
- Up to 8 bytes data transaction in one frame
- 5-V LDO output to supply CAN transceiver
- Diagnostic and protection:
- Programmable fail-safe state
- LED open-circuit detection
- LED short-circuit detection
- Single-LED short-circuit diagnostic
- Programmable low-supply detection
- Open-drain ERR for fault indication
- Watchdog and CRC for FlexWire interface
- 8-Bit ADC for pin voltage measurement
- Overtemperature protection
