MAX1889

製造中止

Triple-Output TFT LCD Power Supply with Fault Protection

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製品情報

High-Performance Step-Up Regulator
- Fast Transient Response
- Current-Mode Control Architecture
- Built-In High-Efficiency N-Channel Power MOSFET
- Current-Limit Comparator > 85% Efficiency
- Selectable Switching Frequency (500kHz/1MHz)
- Internal Soft-Start
Positive Linear-Regulator Controller
Negative Linear-Regulator Controller
Triple-Level Protection Against Smoke or Fire
- Input Switch Replaces Input Fuse
- Output Overload Detection with Timer Latch
- Thermal Shutdown
2.7V to 5.5V Input Operating Range
Ultra-Small External Components
1µA Shutdown Current (max)
1mA Quiescent Current (max)
Ultra-Thin 16-Pin QFN Package (0.8mm Maximum Thickness)

The MAX1889 provides the three regulated output voltages required for active matrix, thin-film transistor liquid crystal displays (TFT LCDs). It combines a high-performance step-up regulator with two linear-regulator controllers and multiple levels of protection circuitry for a complete power-supply system.

The main DC-DC converter is a high-frequency (500kHz/1MHz), current-mode step-up regulator with an integrated N-channel power MOSFET that allows the use of ultra-small inductors and ceramic capacitors. With its high closed-loop bandwidth performance, the MAX1889 provides fast transient response to pulsed loads while operating with efficiencies over 85%. The positive and negative linear-regulator controllers post-regulate charge-pump outputs for TFT gate-on and gate-off supplies.

The MAX1889 has a unique input switch control that can replace the typical input fuse by disconnecting the load from the input supply when a fault is detected. The fault detector monitors all three regulated output voltages and can monitor current from the input supply as well. Additionally, the MAX1889 enters thermal shutdown when its overtemperature threshold is reached.

The MAX1889 undervoltage lockout is set at 2.5V (max) to allow the input supply to droop under pulsed load conditions while avoiding any unexpected behavior when its input voltage dips momentarily. Also, the built-in soft-start and cycle-by-cycle current limiting prevent input surge currents during power-up.

The MAX1889 is available in a 16-pin thin QFN package with a maximum thickness of 0.8mm for ultra-thin LCD panel design.

Applications

Car-Navigation Displays
LCD Monitors
Notebook Computer Displays

ドキュメント

データシート 1

MAX1889: Triple-Output TFT LCD Power Supply with Fault Protection Data Sheet (Rev.1) 12/10/2002

信頼性データ 1

MAX1889 Reliability Data 01/12/2023

これは最新改訂バージョンのデータシートです。

ソフトウェア・リソース

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ハードウェア・エコシステム

製品モデル	製品ライフサイクル	詳細
スイッチング・レギュレータ＆コントローラ 3
MAX1790	新規設計には非推奨	低ノイズ、ステップアップDC-DCコンバータ
MAX1778	新規設計には非推奨	クワッド出力、TFT LCD DC-DCコンバータ、バッファ付
MAX1748	製造中	トリプル出力TFT LCD DC-DCコンバータ
ランプ＆チューブ・ドライバ 2
MAX1996A	製造中止	高効率、広輝度範囲、CCFLバックライトコントローラ

MAX1995

高効率、広輝度範囲、CCFLバックライトコントローラ

評価用キット

Evaluation Kit for the MAX1889

今すぐ購入詳細を表示

機能と利点

2.7V to 5.5V Input Range
Output Voltages
- 9V Output at 200mA (Step-Up Switching)
- 20V Output >10mA (Positive Charge-Pump Regulator)
- -7V Output >10mA (Negative Charge-Pump Regulator)
Resistor-Adjustable Outputs
Up to Three Positive and Three Negative Charge-Pump Stages
Up to +28V and -22V Linear-Regulated Output (As Configured)
90&% Efficiency
500kHz/1MHz Step-Up Switching Frequency
Overcurrent Protection
Low Profile
Surface-Mount Components
Fully Assembled and Tested

製品詳細

The MAX1889 evaluation kit (EV kit) is a fully assembled and tested surface-mount circuit board that contains a step-up switching regulator, a positive three-stage charge-pump and high-voltage positive linear-regulator controller, and a negative three-stage charge-pump and high-voltage negative linear-regulator controller. The step-up switching circuit is configured for a 9V output and provides up to 200mA from a DC supply voltage of 2.7V to 5.5V.

The positive charge-pump and linear regulator are configured for a 20V output using two charge-pump stages providing up to 10mA. The negative charge pump and linear regulator are configured for a -7V output using a single charge-pump stage providing up to 10mA. Power for the positive charge-pump input can be provided by the DC input source or the step-up switching regulator output. Power for the negative charge-pump input can be provided by the DC input source or the power ground.

The MAX1889 EV kit demonstrates low quiescent current and high efficiency (up to 90%) for maximum battery life. The EV kit features overload protection for the input and all outputs. Operation at 1MHz allows the use of tiny surface-mount components. The MAX1889 QFN package (1.0mm max) with low-profile external components allows this circuit to be 1.25mm high.