General description

The ASL3417SHN has a hysteretic buck DC-to-DC topology. With input voltages from

10 V to 80 V, it allows maximum flexibility on output voltages for each channel, enabling

applications with up to 20 LEDs. It also provides an output current of up to and above

1.5 A per channel.1 Furthermore, two output channels can be connected together to

provide an even higher current. It drives an external high-side N channel MOSFET from

an internally regulated adjustable supply. The ASL3417SHN buck driver gives a flexible

system design which can be used to drive three LED strings with the same architecture.

The ASL3417SHN provides an SPI interface for extensive control and diagnostic

communication with an external microcontroller. Furthermore, the ASL3417SHN

integrates a customer programmable Limp-home mode. It allows configurable operation in

Limp-home mode in case SPI communication with the microcontroller has failed.

The ASL3417SHN offers an adjustable hysteresis for optimizing external components as

well as minimizing LED current ripple.

In addition, the ASL3417SHN provides an output voltage of up to 70 V. It has a

measurement capability that can be used to identify LED open or short circuit conditions.

The microcontroller can read this voltage and use it to detect open or short circuit

conditions. There are also additional diagnostic features such as current reached status.

Additional features include input under-voltage lockout and thermal shutdown when the

junction temperature of the ASL3417SHN exceeds +175 C.

It is housed in a very small HVQFN32 pin package with an exposed thermal pad and is

designed to meet the stringent requirements of automotive applications. It is fully AEC

Q100 grade 1 qualified. It operates over the ambient automotive temperature range of

40 C to +125 C.

Features and benefits

 The ASL3417SHN is an automotive grade product that is AEC-Q100 grade 1 qualified.

 Operating ambient temperature range of 40 C to +125 C

 Wide operating input voltage range from +10 V to +80 V

 Able to drive up to 20 LEDs, wide operating LED voltage range regulated from 2.5 V to

70 V

 Output current of up to and above 1.5 A with high LED current accuracy of 5 over

the complete operating temperature range

 Output current programmable via SPI interface

 Read back programmed current via SPI

 Customer programmable Limp-home mode.

 Two output current ranges, programmable via SPI interface with 5 accuracy

 Hysteretic converter

 Fast gate drive for high efficiency

 Programmable internal gate driver voltage regulator

 Support logic level and standard level FETs

 Integrated bootstrap diode

 PWM inputs for individual dimming of each channel

 Low Electro Magnetic Emission (EME) and high Electro Magnetic Immunity (EMI)

 Input voltage monitoring and input under voltage protection

 Output voltage monitoring

 Control signal to enable the device

 Junction temperature monitoring via SPI

 Small package outline HVQFN32

 Low quiescent current < 5A at 25 C when EN = 0

 Short-circuit and open-circuit output protection

Applications

 Automotive LED lighting

 Daytime running lights

 Position or park light

 Low beam

 High beam

 Turn indicator

 Fog light

 Cornering light

 Advanced front lighting