Dual-Channel Synchronous Buck, High-Brightness LED Controller with and without SPI Interface

The MAX20096/MAX20097 are dual-channel, high-voltage, synchronous n-channel high-current buck LED drivers. The ICs use a proprietary average current-mode-control scheme to regulate the inductor current. This control method does not require any control-loop compensation, maintaining nearly constant switching frequency. Inductor current sense is achieved by sensing the current in the bottom switching device. The ICs integrate two fully synchronous buck-converter controllers, and operate over a wide 4.5V to 65V input range. The ICs are designed for high-frequency operation and can operate at switching frequencies as high as 1MHz.

In the MAX20096, the output voltages and currents on both channels and the junction temperature can be read back through the SPI interface. Protection features include inductor current-limit protection, overvoltage protection, and thermal shutdown. The MAX20096 is available in a space-saving thermally enhanced (5mm × 5mm), 32-pin side-wettable TQFN package and is specified to operate over the -40°C to +125°C automotive temperature range.

The MAX20097 is available in a 28-pin thermally enhanced TSSOP package, but does not have the SPI interface. It includes an open-drain fault flag (FLTB) that goes low in case of an open string, shorted string, or overvoltage activation in any one of the channels, or also in thermal shutdown.

Applications

* Automotive Exterior Lighting

* Commercial, Industrial, and Architectural Lighting

* Daytime Running Lights (DRLs)

* Fog Light and Adaptive Front Light Assemblies

* High-Beam/Low-Beam/Signal/Position Lights

* Integration Minimizes BOM for High-Brightness LED Driver, Saving Space and Cost

* Wide 4.5V to 65V Input Voltage Range

* No Compensation Components

* Programmable Switching Frequency

* External MOSFETs that are Sizable for the Appropriate Current

* Wide Dimming Ratio Allows High-Contrast Ratio

* Analog Dimming

* PWM Dimming

* Suitable for Matrix Lighting

* Maintains Current Regulation While Shorting/Opening Individual LEDs in the String

* Ultra-Fast Response Control Loop Prevents Overshoots and Undershoots

* Protection Features and Wide Temperature Range Increase System Reliability

* Short Circuit, Overvoltage, and Thermal Protection

* -40°C to +125°C Operating Temperature Range

* Thermal Monitor and LED Current Monitor

* Fault Diagnosis Through SPI Interface and Through FLTB Pin for Applications without SPI Interface