Six-channel LED drivers target automotive rear lighting

Lumissil Microsystems, a division of Integrated Silicon Solution, Inc. (ISSI), has expanded its automotive lighting portfolio with the addition of the IS32LT3146 and IS32LT3147 LED drivers. The six-channel LED drivers are AEC-Q100 qualified and offer a wide input voltage range of 5 V to 40 V to handle the automotive battery voltage supply range and spikes as well as low headroom voltage. Applications include sequential turn lights, welcome lights, rear lights, and stop or taillights.

The LED drivers provide six channels of adjustable constant current sources that are each adjustable from 10 mA to 75 mA. The channels can be connected in parallel for increased current drive capacity up to a maximum of 450 mA per device. The devices also feature a low headroom voltage and low quiescent current for low power consumption. The max headroom is 500 mV at 25 mA per channel and 900 mV at 75 mA per channel. Both devices operate over a temperature range of -40°C to 150°C.

The devices integrate advanced thermal management and fault protection. The thermal shunt circuitry minimizes driver thermal stress, while the fault detection and reporting offers additional system reliability, said the company. In addition, the current slew rate control optimizes electromagnetic interference (EMI) and the thermal roll-off helps ensure device reliability over its lifetime.

The IS32LT3146 provides additional logic to turn on output channels in groups of one, two, three or six in one-group-after-another-group sequential mode or all-channels blinking on/off mode, said Lumissil. The LED driver is designed for standalone operation where a vehicle’s body control module (BCM) signal powers the device and all functions can be configured via external resistors without a microcontroller host.

The IS32LT3147 device’s output channels provide individual PWM dimming via dedicated PWM input control pins. An off-the-shelf microcontroller host’s GPIOs can be used to control PWM inputs or Lumissil’s IS32LT3134 animation controller could be used with up to two IS32LT3147 instances to modulate up to 12 output current sources for complex pattern playback, said Lumissil.

“If PWM dimming is not required, then IS32LT3147 PWM input control pins could be pulled high to enable for max current output or pulled low to disable the channel while BCM signal powers the device on or off,” said the company.

Both drivers are housed in a thermally-enhanced 6.5 × 4.4 mm eTSSOP-20 package. The IS32LT3146 and IS32LT3147 are priced at $0.99 each in quantities of 1,000.