Automotive 6-Channel Backlight Driver with Boost/SEPIC Controller and IC Interface

The MAX20446 is a 6-channel backlight driver with boost controller for automotive displays. The integrated current outputs can sink up to 130mA LED current each. The device accepts a wide 4.5V to 36V input voltage range and withstands direct automotive load-dump events.

The internal current-mode switching DC-DC controller supports boost or SEPIC topologies and operates in the frequency range 400kHz to 2.2MHz. Integrated spread spectrum helps reduce EMI. An adaptive output-voltage control scheme minimizes power dissipation in the LED current-sink paths.

The device features I2C-controlled pulse-width modulation (PWM) dimming and hybrid dimming. In either case the minimum pulse width is 500ns. Phase-shifted dimming of the strings is incorporated for lower EMI.

Comprehensive diagnostic information is also available through the I2C interface.

The device is available in a 24-pin TQFN package and operates over the -40°C to 125°C temperature range.

Applications

* Central Information Displays * Infotainment Displays * Instrument Clusters

* Wide-Voltage-Range Operation

* Operates Down to 4V Supply After Startup

* Survives Load Dump Up to 52V

* High Integration

* Complete 6-Channel Solution Including Boost Controller

* I2C Control for Minimum Parts Count

* Robust and Low EMI

* Spread-Spectrum Oscillator

* Phase Shifting

* 400kHz to 2.2MHz Switching-Frequency Range

* Fail-Safe Operation Mode Using the FSEN Pin

* Versatile Dimming Scheme Allows Hybrid or PWM-Only Dimming Using DIM Input or I2C

* Dimming Ratio > 10000:1 Using Hybrid Dimming

* 10000:1 Dimming Ratio at 200Hz using PWM Dimming

* Complete Diagnostics

* LED Open/Short Detection and Protection

* Boost Output Undervoltage and Overvoltage

* Boost Voltage

* Individual String LED Current

* Thermal Shutdown

* Compact (4mm x 4mm) 24-Pin TQFN Package