/a>TFT-LCD display” title=”TFT-LCD display”>TFT-LCD display” title=”TFT-LCD display”>TFT-LCD Display power supply solution, integrated a boost converter, a 1.8V /3.3V regulator controller and two gate voltage regulators (one 28V provides 20mA, one negative gate voltage). High-power boost output up to 6W, output voltage up to 18V, operating frequency 2MHz, mainly used in Automobile dashboard, information display and navigation system. This article introduces the main features of MAX16928, block diagram, typical application circuit diagram and the main features of MAX16928 evaluation board, circuit diagram, bill of materials and PCB layout diagram.
The MAX16928 is a highly integrated power supply for automotive TFT-LCD applications. The device integrates one boost converter, one 1.8V/3.3V regulator controller, and two gate voltage regulators. The device comes in several versions to satisfy common automotive TFT-LCD power-supply requirements.
The boost converter uses spread-spectrum modulation to reduce peak interference and to optimize EMI performance.
The sequencing input (SEQ) allows flexible sequencing of the positive-gate and negative-gate voltage regulators. The power-good indicator (PGOOD) indicates a failure on any of the converters or regulator outputs. Integrated thermal shutdown circuitry protects the device from overheating .
The MAX16928 is available in a 20-pin TSSOP package with exposed pad and operates over the -40NC to +105NC temperature range.
Main features of MAX16928:
High-Power (Up to 6W) Boost Output Providing Up to 18V
1.8V or 3.3V Regulator Provides 500mA with External npn Transistor
One Positive-Gate Voltage Regulator Capable of Delivering 20mA at 28V
One Negative-Gate Voltage Regulator
High-Frequency 2.2MHz Operation
Flexible Stand-Alone Sequencing
True Shutdown™ Boost Converter
-40NC to +105NC Operation
Automotive Central Information Displays
Automotive Navigation Systems
Figure 1. Functional block diagram of MAX16928 boost converter
Figure 2. MAX16928 typical application circuit diagram
Evaluation Kit for the MAX16928
The MAX16928 evaluation kit (EV kit) is a fully assembled and tested surface-mount PCB that provides the voltages and features required for automotive thin-film transistor (TFT), liquid-crystal Display (LCD) applications. The EV kit includes a boost converter, a 3.3V regulator controller with external npn transistor, two gate voltage regulators, a single-stage positive charge pump, and a single-stage negative charge pump.
The EV kit can operate from 4.5V to 5.5V input voltages and is optimized for automotive TFT-LCD applications. The boost converter is configured for a 12V output that provides at least 400mA. The regulator controller output is 3.3V and provides at least 500mA . The positive-gate voltage regulator provides 18V output and the negative-gate voltage regulator provides -5.9V.
Main features of the MAX16928 evaluation kit:
4.5V to 5.5V Input Range
12V Output at 400mA (Boost Converter)
3.3V Output at 500mA (Regulator Controller)
18V Output (Positive-Gate Voltage Regulator)
-5.9V Output (Negative-Gate Voltage Regulator)
2.2MHz (Boost Converter)
Single-Stage Positive and Negative Charge Pumps
Proven PCB Layout
Fully Assembled and Tested
Figure 3. MAX16928 evaluation board circuit diagram
MAX16928 Evaluation Kit Bill of Materials (BOM):
Figure 4. The PCB layout of the MAX16928 evaluation board
For details, see: