AAT2822IBK-1-T1 Skyworks

DATA SHEET AAT2822/2823/2824/2825 TFT-LCD DC/DC Converter with WLED Driver and VCOM Buffer General Description Features The AAT2822-AAT2825 family of integrated panel power LCD Bias Power solutions provides the regulated voltages required by an 2.5V to 5.5V Input Supply Range active-matrix thin-film transistor (TFT) liquid-crystal dis- 1.3MHz Fixed Frequency Current-Mode Step-Up play (LCD). The AAT2822 includes a triple-output DC-DC Regulator converter, a LED backlight driver, and a VCOM buffer in Fast Transient Response a 4 mm x 4mm TQFN package. The primary 1.3MHz Adjustable Voltage up to 14.5V DC-DC boost converter uses an ultra-small inductor and 1% Typical Accuracy ceramic capacitor to generate output voltage (V ) of Small External Inductor and Capacitors AVDD up to 14.5V for the charge pumps. The low on-resistance Integrated Soft Start and Sequencing of All Rails of the integrated power MOSFET allows for efficiency up Short-Circuit, Over-Voltage, and Over-Temperature to 93%. Protection Positive Output, VGH The two charge pumps independently regulate a positive Up to 13.2V Input Supply (V ) DD output (VGH) and a negative output (VGL). These low- Adjustable Voltage up to 30V 20mA power outputs use external diode and capacitor stages 3% Typical Accuracy to regulate output voltages up to +30V and down to -30V. A proprietary regulation algorithm minimizes out- Negative Output, VGL put ripple when using small capacitors. Up to 13.2V Input Supply (V ) DD Adjustable Voltage down to -30V 20mA The high efficiency backlight driver provides a constant 3% Typical Accuracy current output capable of boosting up to 28V. The driver WLED Driver is an ideal power solution for backlight applications with Input Voltage Range: 2.5V to 25V up to seven white LEDs in series or up to 39 white LEDs Maximum Continuous Output: in a parallel and series configuration. LED brightness is 12V 260mA PWM controlled up to 1kHz. Filtered PWM is supported 28V 50mA for higher frequencies. Panel sizes from 5 10 The high slew rate operational amplifier is suitable for 5.0 3S5P VCOM buffering and gain adjustment. 5.6 3S6P 7.0 3S9P The sequencing of the power supplies ensures proper 8.0 3S10P/11P panel startup and avoid damage to the device. 10 3S13P The AAT2822 family is available in a Pb-free, 24-pin 4 x Constant LED Current with 6% Accuracy 4mm TQFN package and operates over the -40C to PWM Dimming Control +85C temperature range. Up to 1kHz 1.3MHz Switching Fixed Frequency Up to 90% Efficiency VCOM Buffer High-Performance 13V/s Slew Rate 12MHz, -3dB Bandwidth 75mA Output Short-Circuit Current Low 1.5mA Quiescent Current Applications Automotive Displays Digital Photo Frames Netbooks PNDs Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 1 202081B Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. August 2, 2012 DATA SHEET AAT2822/2823/2824/2825 TFT-LCD DC/DC Converter with WLED Driver and VCOM Buffer Typical Application V IN V AVDD 2.5V - 5.5V L1 D1 C C IN1 AVDDOUT R IN R FB1 LX FB VIN R FB2 C IN2 COMP V DD VDD R COMP C COMP C DRVP D3 DRVN DRVP D2 C DRVN R FBP1 FBN V FBP GL V GH R C FBN1 VGL C R VGH FBP2 R FBN2 REF V IN 2.5V - 5.5V C REF C WIN L2 ON V LED OFF EN D2 Up to 13 strings ON WLX WEN OFF R C PWM OVP1 WOUT WDIM R WCOMP OVP WCOM P R OVP2 C WCOMP WF B VAVDD OPIN OP- R BAL VCOM OUT VCOM IN R OP1 OUT OP+ C COMOUT AGND PGND1 PGND 2 R OP2 Skyworks Solutions, Inc. Phone 781 376-3000 Fax 781 376-3100 sales skyworksinc.com www.skyworksinc.com 2 202081B Skyworks Proprietary Information Products and Product Information are Subject to Change Without Notice. August 2, 2012