MAX17115

Internal-Switch Boost Regulator and High-Voltage, Low-Dropout Linear Regulator for TFT LCDs

Highly Integrated Solution for TFT-LCD Power

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製品情報

2.5V to 5.5V Input Supply Range
Pin-Programmable 640kHz/1.2MHz Switching Frequency
Current-Mode Step-Up Converter
- Fast-Transient Response to Pulsed Load
- High-Accuracy Output Voltage (0.8%)
- Built-In 20V, 4.6A, 0.1Ω n-Channel Power MOSFET
- Cycle-by-Cycle Current Limit
- High Efficiency (88%)
Programmable Soft-Start
High-Performance Operational Amplifier
- 200mA Output Short-Circuit Current
- 45V/µs Slew Rate
- 20MHz -3dB Bandwidth
- Rail-to-Rail Input and Output
High-Voltage LDO
- High ±0.5% Accuracy
- 40mA Guaranteed Output Current
Logic-Controlled High-Voltage Switch with Adjustable Delay
High-Voltage Stress Mode
Built-In Sequencing
Thermal-Overload Protection
Gate Driver for Input-Side True Shutdown™ Switch
Logic-Level Shutdown Input
Timer-Delayed Fault Shutdown for Boost-Regulator Output

The MAX17115 includes a high-performance step-up regulator, a high-accuracy, high-voltage, low-dropout linear regulator (LDO), a high-performance buffer ampifier, and a logic-controlled high-voltage switch block.

The DC-DC converter is a high-frequency (1.2MHz/640kHz) current-mode step-up regulator with a built-in power MOSFET. It provides fast-transient response to pulsed loads while producing efficiencies over 88%. The built-in power MOSFET allows output voltages as high as 18V from inputs from 2.5V to 5.5V. A programmable soft-start function controls startup inrush currents.

The operational amplifier, typically used to drive the LCD backplane (VCOM), features high-output short-circuit current (200mA), fast slew rate (45V/µs), and wide bandwidth (20MHz). Its rail-to-rail input and output maximize application flexibility. The high-voltage LDO is adjustable and has a high accuracy of ±0.5%. It is typically used to drive a gamma reference divider string. The high-voltage switch control block modulates the shape of the gate-on supply and provides an adjustable delay for power-up sequencing.

The high-voltage stress (HVS) function is used to temporarily increase the source-driver supply voltage of the LCD panel for aging tests. The HVS digital input controls an open-drain internal switch, which is typically used to change the feedback divider of the step-up regulator.

The MAX17115 is available in a lead-free, 32-pin, thin QFN package. The package is a 5mm x 5mm square with a maximum thickness of 0.8mm for thin LCD panel design.

Applications