Simplified Block Diagram
- 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
- Automotive Central Information Displays
- Automotive Dashboards
- Automotive Head Up Displays
- Automotive Navigation System
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.