MAX25530

Automotive I²C-Controlled 4-Channel 150mA Backlight Driver and 4-Output TFT-LCD Bias

Industry's First Automotive TFT Bias with 4 CH LED Driver

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Overview

Features and Benefits
Product Details

Features and Benefits

4-Output TFT-LCD Bias Power
- 2.8V to 5.5V Input for the TFT-LCD Section
- Integrated 430kHz or 2.2MHz Boost and Buck-Boost Converters
- Positive and Negative 10mA Gate Voltage Regulators (Tripler/Inverting Doubler) with Adjustable Output Voltage
- Flexible Resistor-Programmable Sequencing through the SEQ Pin
- Undervoltage Detection on All Outputs
- Low-Quiescent-Current Standby Mode
4-Channel LED Backlight Driver
- Up to 150mA Current per Channel
- 4.5V to 42V Input Voltage Range
- Integrated Boost/SEPIC Controller (440kHz or 2.2MHz)
- Dimming Ratio 10,000:1 at 200Hz
- Adaptive Voltage Optimization to Reduce Power Dissipation in the LED Current Sinks
- Open-String, Shorted-LED, and Short-to-GND Diagnostics
Low EMI
- Phase-Shift Dimming of LED Strings
- Spread Spectrum on LED Driver and TFT
- Selectable Switching Frequency
I²C Interface for Control and Diagnostics
- Fault Indication through the FLTB pin and I²C
- Auto-Retry after Fault Detection
Overload and Thermal Protection
-40°C to +105°C Ambient Temperature Operation
40-Pin (6mm x 6mm) TQFN Package with Exposed Pad
AECQ100 Grade 1

Product Details

The MAX25530 is a highly integrated TFT power supply and LED backlight driver IC for automotive TFT-LCD applications. The IC integrates one buck-boost converter, one boost converter, two gate-driver supplies, and a boost/SEPIC converter that can power one to four strings of LEDs in the display backlight.

The source-driver power supplies consist of a synchronous boost converter and an inverting buck-boost converter that can generate voltages up to +18V and down to -7V. The positive source driver can deliver up to 120mA, while the negative source driver is capable of 100mA. The positive source-driver supply-regulation voltage (V_POS) is set by connecting an external resistor-divider on FBP or through I²C. The negative source-driver supply voltage (V_NEG) is always tightly regulated to -V_POS (down to a minimum of -7V). The source-driver supplies operate from an input voltage between 2.8V and 5.5V.

The gate-driver power supplies consist of regulated charge pumps that generate from +28V to -21.5V and can deliver 10mA or more each depending on the exact configuration.

The IC features a quad-string LED driver that operates from a separate input voltage (V_BATT) and can power up to four strings of LEDs with 150mA (max) of current per string. The IC features logic-controlled pulse-width-modulation (PWM) dimming, with minimum pulse widths as low as 500ns with the option of phase shifting the LED strings with respect to one another. When phase shifting is enabled, each string is turned on at a different time, reducing the input and output ripple, as well as audible noise. With phase shifting disabled, the current sinks turn on simultaneously and parallel connection of current sinks is possible.

The startup and shutdown sequences for all power domains are controlled using one of the seven preset modes, which are selectable through a resistor on the SEQ pin or through the I²C interface. The MAX25530 is available in a 40-pin (6mm x 6mm) TQFN package with an exposed pad, and operates over the -40°C to +105°C ambient temperature range.

Applications

Automotive Central Information Displays
Automotive Dashboards
Automotive Head Up Displays
Automotive Navigation System

Product Categories

Power Management
- LCD/CCD/OLED Bias
- Step-Up (Boost) LED Drivers

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Evaluation Kits (1)

MAX25530EVKIT

Evaluation Kit for the MAX25530

MAX25530EVKIT

View Detailed Evaluation Kit Information

The MAX25530 evaluation kit (EV kit) demonstrates the MAX25530 IC, which is a highly integrated power supply plus LED backlight driver for automotive TFT-LCD applications. The EV kit is a fully assembled and tested surface-mount PCB that provides a complete power-management solution for automotive displays. The EV kit demonstrates one buck-boost converter, one boost converter, two gate-voltage controllers, and a boost converter that powers a quad-string LED driver.

The EV kit can be configured to operate in a stand-alone mode or in an I²C mode.

The TFT bias section of the EV kit operates from a 2.8V to 5.5V DC supply voltage. The step-up switching regulator (POS) is configured for a 5V to 18V output that provides up to 120mA. The inverting buck-boost converter (NEG) generates a negative output that tracks the positive output (down to a minimum of -7V) and provides up to 100mA. The gate-driver power supplies consist of regulated charge pumps that generate +28V (DGVDD) and -21.5V (DGVEE) and can deliver up to 10mA each, depending on the POS setting. Operation at 430kHz and 2.2MHz is possible.

The LED driver section demonstrates a step-up DC-DC pre-regulator followed by four channels of linear current sinks. The step-up pre-regulator switches at 2.2MHz or 440kHz and operates as a current-mode controlled regulator capable of providing up to 600mA for the current sinks. Each channel can operate up to 48V and provides up to 150mA.

The LED driver portion of the EV kit operates from a DC supply voltage of 4.5V up to the High-Brightness (HB) LED string-forward voltage. The EV kit can withstand a 52V load-dump condition. The EV kit also demonstrates the IC’s features, such as adaptive voltage optimization, Overvoltage and Undervoltage protection, cycle-by-cycle current limit, thermal shutdown, and digital PWM dimming operation using a digital PWM input signal to control the brightness of the HB LEDs.

The EV kit provides an I²C interface that can operate in conjunction with the MINIQUSB+ adapter board or a third-party I²C master. The EV kit also includes Windows^®-compatible software that provides a simple graphical user interface (GUI) for exercising the features of the IC.

Applications

Automotive Central Information Displays
Automotive Dashboards
Automotive Head Up Displays
Automotive Navigation System

Features & Benefits

Demonstrates Robustness of MAX25530
2.8V to 5.5V Input Range for TFT Power Section
4.5V to 42V Input Range for LED Driver Section
2.2MHz or 430kHz I²C programmable Boost and Inverted Buck-Boost Switching Frequency with Spread-Spectrum Option on TFT Power Section
2.2MHz or 440kHz I²C programmable Boost Frequency with Spread-Spectrum Option on LED Driver Section with four 150mA LED drivers
TFT Section Default Output Voltages (Stand-alone Mode)
- +6V Output at 120mA (Step-Up Switching Regulator)
- -6V Output at 100mA (Inverting Buck-Boost Switching Regulator)
- +16V Output at 10mA (Positive-Charge Pump)
- -7V Output at 10mA (Negative-Charge Pump)
HB LED String Output Currents Configurable for 20mA, 50mA, 100mA, 120mA or 150mA
Flexible Resistor-Programmable TFT Output Sequencing (Stand-alone Mode)
Demonstrates Cycle-by-Cycle Current-Limit and Thermal-Shutdown Features on Boost LED Driver
Demonstrates Adaptive Voltage Optimization on LED Driver Section
I²C Programmability
Dedicated GUI
Proven PCB Layout and Thermal Design
Fully Assembled and Tested

Resources

MAX25530EVKIT ODB File - Design Files

TGZ

1.07M

Documentation & Resources

Data Sheets

MAX25530: Automotive I²C-Controlled 4-Channel 150mA Backlight Driver and 4-Output TFT-LCD Bias Data Sheet (Rev. 0)
5/13/2021

PDF

998K

Videos

Introduction to the MAX25530 Automotive I2C Controlled 4 Channel 150mA Backlight Driver and 4 Output TFT Bias
11/29/2022

Technical Articles

LED Driver for Automotive Display Applications
9/24/2021

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.