The MAX25605 is a six-channel automotive sequential LED controller. The device implements a sequential turn function or any other sequential light animation without the use of a microcontroller or software. The MAX25605 integrates six cascoded low RDSON n-channel MOSFETs suitable for LED lighting applications up to 750mA. Each switch supports up to three series LEDs per switch. The entire LED string voltage supported is up to 60V. The n-channel MOSFETs are divided into two groups of three, allowing a single device to sequence either one or two strings of LEDs. Integrated gate drivers and level shifters for the switches are supplied by an internal charge-pump regulator, supporting buck-boost and boost-to-battery applications, in addition to ground-referenced LED driver topologies.
Sequencing functionality and timing is programmed by connecting resistors to the A0, A1, A2, and CLK inputs. Programming options include: dimming up/down, short LED threshold, multi-device sequence position, dimming frequency, and fade duration. The optional logarithmic fade feature allows for gradually turning the LEDs on or off. The sequence can be disabled by pulling the enable input low. With EN pulled low, the switches are open and the LED driver current flows through the entire LED string. Each switch also integrates single-LED fault detection, asserting a fault flag in case of shorted LEDs, open LEDs, or open wires between the sequencer and the LED string. Additionally, up to 16 devices can be sequenced together through the use of a SYNC input.
The MAX25605 operates over the -40°C to +125°C automotive temperature range and is available in a 20-pin 4mmx4mm side-wettable TQFN and a 20-pin TSSOP package with exposed pad.
Applications
- Hardware-Based Lighting Animation
- Sequential Turn Signal Lights
