淺析汽車TFT-LCD顯示器升壓電源的解決方案

Maxim公司的MAX16928是高度集成的汽車TFT-LCD顯示器電源,器件集成了一個升壓轉換器(高達6W,輸出高達18V),一個1.8V/3.3V穩壓控制器(500mA電流)和兩個柵極電壓穩壓器,其中的正柵極電壓穩壓器能在28V時提供20mA電流,高頻2.2MHz工作,提供軟起動和超溫關斷等功能.主要用在汽車儀表盤,汽車中心信息顯示器和汽車導航系統.本文介紹了MAX16928主要特性,方框圖, 正輸出和負輸出電壓的多級電荷泵電路以及典型應用電路.

Automotive TFT-LCD Power Supply with Boost Converter and Gate Voltage Regulators

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.

MAX16928主要特性:

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

Internal Soft-Start

Overtemperature Shutdown

-40NC to +105NC Operation

AEC-Q100 Qualified

MAX16928應用:

Automotive Dashboards

Automotive Central Information Displays

Automotive Navigation Systems

圖1.MAX16928升壓轉換器功能框圖

圖2.正輸出電壓的多級電荷泵電路

圖3.負輸出電壓的多級電荷泵電路

圖4.MAX16928應用電路圖