General Description

The MAX25561 is a 6-channel LED backlight driver with an integrated current-mode boost controller that operates over a switching frequency range of 400kHz to 2.2MHz and incorporates spread spectrum. Selectable phase-shifting of the output channels is included to reduce EMI. The MAX25561 provides up to 220mA per channel. The device is capable of operating down to very low battery voltages by virtue of a unique input voltage switching scheme.

Extensive diagnostics and an I2C interface are included to assist with system ASIL B compliance.

The MAX25561 is available in a compact TQFN package and operates over the -40°C to +125°C temperature range.

Benefits and Features

•Operates Down to 3V on Battery Input whileMaintaining 5V Gate Drive

•Wide Boost Duty-Cycle Range

•Boost or SEPIC Current-Mode DC-DC Controller

•400kHz to 2.2MHz Operating Frequency Range

•Optional Spread Spectrum

•Can Be Synchronized to an External Clock

•LED Current Sinks

•Up to 220mA Output Current per String

•Low OUT_ Regulation Voltage

•Optional Phase-Shifting Between Channels

•15000:1 Dimming Ratio at 200Hz

•External or Internal (I2C) Dimming

•>15000:1 Dimming Ratio with Hybrid Dimming

•Integrated Charge-Pump to Drive Series nMOSFET

•Temperature Foldback Using External NTCTemperature Sensor

•Fast Startup Option without I2C Intervention UsingEN Pin Only

•FLTB Output Provides Diagnostic Information

•Shorted or Open LEDs

•Any OUT_ Pin Shorted to GND

•IREF/RT Resistor Out of Range

•Thermal Warning/Shutdown

•Undervoltage/Overvoltage on Boost Output

•Bandgap Out-of-Range/Internal Oscillator Failure

•V18 Internal Supply out-of-Range

•Input Overcurrent (Measured at Boost InputUsing External Sense Resistor)

•Input/Output PWM Comparison

•Continuous Output Current Measurement andCurrent Mismatch (Shutdown/Flag)

•I2C Interface with CRC

•Readback of Measured DIM Pin Duty Cycle andFrequency

•Compact TQFN Package

Applications

•Automotive Instrument Clusters

•Automotive Central Information Displays

•Automotive Head-Up Displays