Features and Benefits
- 4-Output TFT-LCD Bias Power
- 2.8V to 5.5V Input for the TFT-LCD Section
- Integrated 440kHz or 2.2MHz Boost and Buck-Boost Converters
- Positive and Negative 3mA Gate Voltage Regulators 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 with Fine-Tuning via I2C
- I2C Interface for Control and Diagnostics
- Fault Indication through the FLTB pin and I2C
- Overload and Thermal Protection
- -40°C to +105°C Ambient Temperature Operation
- 40-Pin (6mm x 6mm) TQFN Package with Exposed Pad
The MAX20069B 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 +15V 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 (VPOS) is set by connecting an external resistor-divider on FBP or through I2C. The negative source-driver supply voltage (VNEG) is always tightly regulated to -VPOS (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 up to +28V and -21.5V and can deliver up to 3mA each.
The IC features a quad-string LED driver that operates from a separate input voltage (VBATT) 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 each other. 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 MAX20069B 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.
- • Automotive Central Information Displays
- • Automotive Dashboards
- • Automotive Head Up Displays
- • Automotive Navigation System
Product Lifecycle Production
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
Evaluation Kits (1)
The MAX20069 evaluation kit (EV kit) demonstrates the MAX20069 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 powermanagement solution for small-size 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 stand-alone mode or in I2C mode.
The TFT bias portion 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 4V to 18V output that provides up to 150mA. 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 (GVDD) and -21.5V (GVEE) and can deliver up to 3mA each.
The LED driver portion of the EV kit operates from a DC supply voltage of 4.5V up to the 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.
*Note: To be ordered separately.
- Automotive Central Information Displays
- Automotive Dashboards
- Automotive Head Up Displays
- Automotive Navigation System
Features & Benefits
- Demonstrates Robustness of MAX20069
- 2.8V to 5.5V Input Range for TFT Power Section
- 4.5V to 42V Input Range for LED Driver Section
- 2.2MHz or 440kHz 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 150mA (Step-Up Switching Regulator)
- -6V Output at 100mA (Inverting Buck-Boost Switching Regulator)
- +16V Output at 3mA (Positive-Charge Pump)
- -7V Output at 3mA (Negative-Charge Pump)
- HB LED String Output Currents Configurable for 20mA, 50mA, 100mA, 120mA or 150mA
- 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
Documentation & Resources
Tools & Simulations
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.
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Pricing displayed is based on 1-piece. The USA list pricing shown is for budgetary use only, shown in United States dollars (FOB USA per unit), and is subject to change. International prices may vary due to local duties, taxes, fees and exchange rates.