EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Introduction The AAT2893 evaluation board demonstrates the functionality of the AAT2893 and its application as a highly integrated lighting management unit (LMU) which is optimized for single-cell lithium-ion/polymer battery powered systems and is ideal for portable devices. The AAT2893 integrates a high voltage DC/DC boost converter and is designed to drive up to 10 backlight LEDs in series from a 3.0V to 5.5V input voltage source. Through the I2C interface, the AAT2893 can be programmed with 28.6mA to 0.23mA backlight current and the output voltages of four LDOs are programmable from 1.2V to 3.3V. To reduce overall power consumption, the AAT2893 supports CABC by providing high frequency filtered PWM for contentbased dimming and automatic ambient light control for varying lighting conditions. The ambient light control (ALC) includes a regulated bias supply to power an ambient light sensor (ALS) or a photo diode. The integrated ADC polls the ambient light conditions and is readable through the I2C interface. The ambient light control can also be configured to automatically adjust backlight brightness for changing ambient lighting conditions. This document describes the evaluation board and its accompanying user interface. In addition, a brief “Getting Started” section is included to help the user begin operating the evaluation board. The AAT2893 evaluation board is shown in Figure 1. The schematic of the complete circuit is shown in Figure 2. For additional information, please consult the AAT2893 product datasheet. Board Pictures (a) Top Side. (b) Bottom Side. Figure 1: AAT2893 Evaluation Board Pictures. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 1 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Board Schematic 1 3 5 7 9 LDOA LDOB ILED D1 E3 E2 COMP LDOD C2 4.7µF 2 4 6 8 10 A3 TP4 A2 C8 2.2µF A1 C9 2.2µF TP9 SBIAS C10 2.2µF LDOD SBIAS GC2 R13 0Ω 1 R10 (open) 2 R12 0Ω 3 U2 OUT GC2 GND GC1 VCC NC P3 GC2 6 5 4 SBIAS GC1 BH1600FVC GND Figure 2: AAT2893 Evaluation Board and I2C USB Board Schematic. 2 LDOC TP5 C2 AMB_ IN Gnd SDA C4 2.2µF A4 DGND LDOC TP3 LDOB B1 Header 5X 2 GND LDOA C3 2.2µF TP6 P5 SCL TP2 VIN FLTR B4 PWM R2 0Ω PWM D6 JP3 U1 AAT2893 SDA E4 C6 56nF EN D3 • JP2 SDA VIN D4 D7 SCL P2 C7 10nF D8 C3 R11 100kΩ PWM D2 • • D9 SCL EN D10 JP1 IN _LDO AMB_IN R9 100kΩ PWM D11 IN C4 B3 TP10 OUT E1 LX B2 D5 • • SDM20U40 VIN D4 C1 • SBIAS P1 D3 • DS1 C1 4.7µF VIN D2 PGND L1 4.7µH TP1 D1 AGND C5 2. 2µF Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 P4 GC1 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs I2C USB Communication Board Since the AAT2893 is controlled by I2C interface, an USB interface board is necessary to connect the computer and the AAT2893 demo board, and build the communication between the computer and AAT2893 demo board. The picture of USB interface board is shown in Figure 3. Please pay attention to the compatible pin configuration between J5 on the demo board and J0 on the USB interface board as indicated in Figure 4. (a) Top View. (b) Bottom View. Figure 3: AATI I2C USB Interface Board Pictures. P5 SCL 1 3 5 7 9 2 4 6 8 10 Header 5x2 GND SDA J0 P0.5 SCL P0.3 CSB P0.2 SDI 1 3 5 7 9 2 4 6 8 10 GND P0.4 SDA P0.1 SDO P0.0 SCLK Header 5x2 Figure 4: Compatible Connector on EV Board and I2C USB Interface Board. This USB board has 2 communication ports, one for USB port, connecting to USB I/O port of the computer with a USB wire; the other one for 5x2 Header, connecting to 5x2 header with a 10 flat cable on the AAT2893 Demo Board. Figure 5: I2C USB Board Connection. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 3 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Windows GUI Installation The I2C serial interface is a widely-used interface which requires a master to initiate all communications with the slaves. I2C protocol consists of 2 active wires, SDA (serial data line) and SCL (serial clock line). Both wires are open-drain and require an external pull-up resistor to VCC. The SDA pin serves as I/O function, and the SCL pin controls and references the I2C bus. As the AAT2893 is controlled by I2C interface, AATI provides a Windows GUI Program which can be controlled by computer to achieve the I2C communication. Please contact FAE to install the Windows GUI Program. The steps of Windows GUI installation are listed as below: Step 1: Click the setup file, then a dialog box will appear as below. Click “Next” to continue. 4 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Step 2: Choose the installation folder and user range, then click “Next” to continue. Step 3: Click “Next” to continue. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 5 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Step 4: Installing. Step 5: Installation Completed. Click “Close” to end the installation process. The Windows GUI is installed successfully. When you open the Windows GUI program, the initial workspace is shown as Figure 9. 6 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Getting Started The AAT2893 uses an I2C serial interface to set backlight LED current and LDO ON/OFF and output voltage, as well as other housekeeping functions. AATI provides a Windows GUI Program which can be controlled by computer to establish the I2C communication. Board Configuration and Connection The evaluation is performed using a bench test setup with or without a signal source for PWM. Figure 7 shows the typical connection without external PWM signal source. Figure 8 shows the typical connection with external PWM signal source. Table 1 highlights the steps for configuring the board and making the correct connection to the appropriate test equipment. Step Action Function Enable AAT2893 Step1: configure the evaluation board Set P1 to “on” position Set P2 to “100%” position as default or connect the middle pin of P2 to external signal source when external PWM signal is applied. Set GC1 = 0 and GC2 = 1. Step2: make connection Connect P5 to the header of the I C USB board. Step3: open Windows GUI Step4: apply power to the board Step5: operate the Windows GUI Program Open AAT2893 Windows GUI and ensure Device Status to be connected. A DC power supply is applied to VIN and GND terminals of the AAT2893 evaluation board. Refer to the “Windows GUI Software Introduce” section. 2 Configure PWM Dimming. Set ambient light sensor gain mode. Find the way of communication between the AAT2893 and the computer. Prepare for I2C interface control. Power the AAT2893 and enable it with 3.0V ~ 5.5V. Set appropriately to achieve necessary functions. Table 1: Steps of Getting Evaluation Board Started. Building Up Steps: The board has two terminals labeled VIN and GND for the input power supply connection, and has a 5 × 2 header (P5) for the connection between the demo board and the USB interface board. The computer and the USB interface board are connected by a USB wire. Figure 6 shows the typical connection. 1. Connect the computer and USB interface board via an USB wire. 2. Set P1 to “ON” position, set P2 to “100%” position. 3. Connect JP1 on the demo board for enabling 10-LED string, or connect JP2 on the demo board for 8 LEDs, and connect JP3 on the demo board for 10 LEDs. Connect to the power supply AAT2893 Demo Board I2C USB Board Connect to the AAT2893 demo board via a ten flat cable Computer Connect to the computer via an USB wire Figure 6: Picture of AAT2893 Evaluation Board Demonstration Connection without External PWM Signal Source. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 7 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Power Supply Computer 2.7V~5.5V USB I/O Port Connection between Computer and AATI USB Interface Board via an USB wire for I2C control Connection between AAT2893 Demo Board and AATI USB Interface Board via a ten flat cable for I2C control Figure 7: AAT2893 Evaluation Board Demonstration Connection without External PWM Signal Source. Computer USB I/O Port Signal Source Power Supply 2.7V~5.5V Square wave Freq=100~10kHz VPWM(H) =2.2V~VIN Connection between Computer and AATI USB Interface Board via an USB wire for I2C control Connection between AAT2893 Demo Board and AATI USB Interface Board via a ten flat cable for I2C control Figure 8: AAT2893 Evaluation Board Demonstration Connection with External PWM Signal Source. 8 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Run AAT2893 Windows GUI program on the computer. Make sure the USB interface board is connected and ready for communication. Figure 9 and 10 (snap connection status) show connection status and how to set up the connection between the computer and I2C USB board. USB Interface Board has connected to computer Figure 9: Connection Status between I2C USB Board and Computer. USB Interface Board has not connected to computer Figure 10: No connection Status between I2C USB Board and Computer. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 9 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs The AAT2893 has 28 registers listed in Table 2: • Four for backlight enable, and control and configuration of fade in/out function. • Twenty-one for ambient light sensor control and configuration. • Three for LDOs control and configuration. REG Function Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 BL[6] BL[5] BL[4] BL[3] BL[2] BL[1] BL[0] 0 0 0 0 0 0 BL_EN CABC_EN 0 0 0 0 FLR[3] FLR[2] FLR[1] FTIME[1] FTIME[0] FADE_EN Name Hex ILED 00h BL_ENBLS 01h FADE_FLR 02h Backlight LED Current BL & CABC Enables Fade Floor FADE 03h Fade Control ALC_FADE ALS_CFG0 04h 05h ALC Fade Time ALS Functions PMODE ALS_CFG1 06h SBIAS ON/OFF OFF_TM ALS_CFG2 07h AMLRB 08h ALS_BL0 ALS_BL1 ALS_BL2 ALS_BL3 ALS_BL4 ALS_BL5 ALS_BL6 ALS_BL7 ALS_BL8 ALS_BL9 ALS_BLA ALS_BLB ALS_BLC ALS_BLD ALS_BLE ALS_BLF LDO_AB LDO_CD LDO_EN 09h 0Ah 0Bh 0Ch 0Dh 0Eh 0Fh 10h 11h 12h 13h 14h 15h 16h 17h 18h 19h 1Ah 1Bh ALS input gain/ offset Ambient Level (Read) ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data ALS Data LDO Select LDO Select LDO Enable RSET[2] OS_ ADJ[3] RSET[1] OS_ ADJ[2] RSET[0] OS_ ADJ[1] ALCFU[1] GAIN[1] OS_ ADJ[0] ALCFU[0] GAIN[0] ALCFD[1] GM_SEL FLR[0] INIT_ FADE ALCFD[0] ALS_EN SB[1] SB[0] SB_EN SNSR ALSOUT PTIME[1] PTIME[0] G_ADJ[3] G_ADJ[2] G_ADJ[1] G_ADJ[0] AMB[7] AMB[6] AMB[5] AMB[4] AMB[3] AMB[2] AMB[1] AMB[0] LDOA[3] LDOC[3] 0 ALS0[6] ALS1[6] ALS2[6] ALS3[6] ALS4[6] ALS5[6] ALS6[6] ALS7[6] ALS8[6] ALS9[6] ALSA[6] ALSB[6] ALSC[6] ALSD[6] ALSE[6] ALSF[6] LDOA[2] LDOC[2] 0 ALS0[5] ALS1[5] ALS2[5] ALS3[5] ALS4[5] ALS5[5] ALS6[5] ALS7[5] ALS8[5] ALS9[5] ALSA[5] ALSB[5] ALSC[5] ALSD[5] ALSE[5] ALSF[5] LDOA[1] LDOC[1] 0 ALS0[4] ALS1[4] ALS2[4] ALS3[4] ALS4[4] ALS5[4] ALS6[4] ALS7[4] ALS8[4] ALS9[4] ALSA[4] ALSB[4] ALSC[4] ALSD[4] ALSE[4] ALSF[4] LDOA[0] LDOC[0] 0 ALS0[3] ALS1[3] ALS2[3] ALS3[3] ALS4[3] ALS5[3] ALS6[3] ALS7[3] ALS8[3] ALS9[3] ALSA[3] ALSB[3] ALSC[3] ALSD[3] ALSE[3] ALSF[3] LDOB[3] LDOD[3] LDO_END ALS0[2] ALS1[2] ALS2[2] ALS3[2] ALS4[2] ALS5[2] ALS6[2] ALS7[2] ALS8[2] ALS9[2] ALSA[2] ALSB[2] ALSC[2] ALSD[2] ALSE[2] ALSF[2] LDOB[2] LDOD[2] LDO_ENC ALS0[1] ALS1[1] ALS2[1] ALS3[1] ALS4[1] ALS5[1] ALS6[1] ALS7[1] ALS8[1] ALS9[1] ALSA[1] ALSB[1] ALSC[1] ALSD[1] ALSE[1] ALSF[1] LDOB[1] LDOD[1] LDO_ENB ALS0[0] ALS1[0] ALS2[0] ALS3[0] ALS4[0] ALS5[0] ALS6[0] ALS7[0] ALS8[0] ALS9[0] ALSA[0] ALSB[0] ALSC[0] ALSD[0] ALSE[0] ALSF[0] LDOB[0] LDOD[0] LDO_ENA Table 2: AAT2893 Register Allocation (“0” must write 0; Blank Space = Unassigned). Windows GUI Introduction The Windows GUI program can be executed on computer after installation is completed. We should make sure the connection follow Step1 and Step2 in Table 1 before opening and configuring the program. This Windows GUI Program has 6 sheets: “Backlight”, “ALS Setup” and “LDO” sheets for function configuration, “Register” sheet for register operation, “Script” sheet for Saving and Loading customers' files, and “Log” sheet for recording operated code and register addresses. 10 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs “Backlight” Sheet Description: Figure 11: Backlight Sheet. This sheet is for basic function operation for LED backlight, and the operating items are shown as below: • • • • • • • Enable Backlight LED. CABC PWM Input Enable. Backlight LED Current, from 0 to 28.6mA with per step 0.23mA. Enable Fade In/Out. Fade Time: there are four items including 1s,0.8s,0.6s,0.4s for your choice. Fade Floor Level: the 16 current levels can be chose to be the fade floor level. Fade In and Fade Out Button. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 11 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs “ALS Setup” Sheet Description: Figure 12: ALS Setup Sheet. All operation about ALS are involved in this sheet. It includes 3 blocks. The left block is about ALS parameter setting, configuration and adjustment. These parameters includes: • VALS(MAX) Without Gain Adjustment, the VALS(MAX) should be 1.6V; but If we choose Gain Adjustment, the VALS(MAX) should be calculated as below: VALS(MAX) = 1.6 1 + Gain_ADJ • Max/Floor brightness: Range of ambient light brightness • Max/Floor LED current: Range of LED current • ALS output The item reflects the relationship between ambient light brightness and ALS output current. The evaluation board uses BH1600FVC as ALS that has two gain modes. In High gain mode, the ALS output gain is 6μA/10Lux, and in Low gain mode, it is 0.63μA/10Lux. The gain mode can be chose by setting the GC1 and GC2 level. In order to set the GC1 and GC2 level, we could change P3 and P4 of the evaluation board connection. • ALS Sensor Type It has 2 options: “linear” and “logrithmic”, depending on the characteristics of the ambient light sensor. For the BH1600FVC, we set it to be “linear”. • Digital ALS Output 12 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs • • • • • • • • It has 2 options: “linear” and “logrithmic”, which is used to divide LED current into 16 groups with “linear/Logrithmic” trend. ALC Backlight Profile It has 2 options: “linear” and “logrithmic”, which is used to divide LED current into 16 groups as “linear/Logrithmic” trend. Gain Resistor Pair There are 6 pairs of resistor including 500Ω/2kΩ, 1kΩ/4kΩ, 2kΩ/8kΩ, 4kΩ/16kΩ, 8kΩ/32kΩ and 16kΩ/64kΩ. Select a suitable resistor to get enough voltage to achieve better precision. If the ALS output voltage exceeds the SBIAS, an external voltage source is needed to power the ALS. At this time, we should click the “External ALS BIAS Supplied” button at the upper right of this sheet. If the resistor included in AAT2893 is not suitable, we could also use an external resistor. Example 1 on Page 36 of the AAT2893 datasheet provides a way to calculate the Gain Resistor. Output Offset Adjustment Any leakage current will cause an offset at the output of ambient light sensor, leading to inaccurate measurement of the light brightness. Example 2 on Page 36 of the AAT2893 datasheet provides a way to correct the offset. Input Gain Adjustment For the ambient light sensor, the part-to-part variation of the output current is guaranteed to be ±20% at best. Because of the part-to-part difference of input gain, we need output gain adjustment to achieve a constant input gain. Please refer to “Ambient Light Sensor Gain Adjustment” and “Ambient Light Sensor Voltage Bias” on Page 39 to Page 40 of the AAT2893 datasheet for details of Gain Adjustment Setting. SBIAS Output The SBIAS can be set to 3V, 2.8V, 2.7V, 2.6V. Because SBIAS is supplied by an internal LDO of the AAT2893, the voltage can’t be set higher than VIN. In evaluation board, SBIAS power the ambient light sensor. Input Gain Mode There are four options for input gain modes, including auto gain mode, fixed gain mode, high gain mode and low gain mode. When we select the auto gain mode, the gain mode will change auotmatically between high gain mode and low gain mode according to the ambient light brightness. The AAT2893 will choose low gain resistor when the ambient light is bright, and high gain resistor when the ambient light is dim. If choose the fixed gain mode, an external gain resistor is needed. Polling Mode The AAT2893 allows automatic and manual mode for measurement of the ambient light sensor brightness. Choosing automatic mode, the AAT2893 will periodically update the information about the surrounding brightness at an interval of every elapsed time. Polling Time There are four options for Polling Time: 0.5s, 1s, 1.5s and 2s. An Guide for ALS Configuration is provided in lower left of this sheet to guide the user to set ALS parameters step by step easily. This Guide has 8 steps. It gives the brief description for each step, and when selecting any one of steps, the color-changing parameter item emphasize it should be configured in this step. Please refer to Figure 13 and 14 for the example: Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 13 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs ALS Configuration Guide Figure 13: Ambient Light Sensor Setup Guide. Color-Changing Item Figure 14: Example of Ambient Light Sensor Setup Guide. 14 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs After setting and adjusting ALS parameters in the left block of this sheet, the middle block lists a 16-ALS LED Current Dimming Register (ALS0 ~ ALSF) table corresponding to brightness, LED current and data of ALS LED Current Dimming Register. Unselecting the “change dimming level data automatically”, the “data” in the middle block can be modified by the user. But the calculation is so complicated to achieve logarithmic response or linear response, so we don’t advise to configure manually, and this function is selected by default. Once the “change dimming level data automatically” is selected, the registers data in the middle block will be correlated by the configuration of “Max Brightness”, “Floor Brightness”, “Max LED Current”, “Floor LED Current”, “Digital ALS Output” and “ALC Backlight Profile” in the left block automatically. Table 3 lists the equations of brightness and LED current with “Linear Trend” and “Logarithmic Trend”. Number Equation 1 Equation 2 Equation Comment lg BrightnessMAX BrightnessFLOOR Brightness(NREG) = BrightnessFLOOR ∙ 10 Brightness(NREG) = BrightnessFLOOR + 15 IALS = IFLOOR ∙ 10 Equation 4 IALS = IFLOOR + IMAX IFLOOR 15 IMAX - IFLOOR 15 ∙ NREG ∙ NREG Brightness grouping calculation with Logarithmic Trend ∙ NREG BrightnessMAX - BrightnessFLOOR lg Equation 3 15 ∙ NREG Brightness grouping calculation with Linear Trend LED current grouping calculation with Logarithmic Trend LED current grouping calculation with Linear Trend Table3: The Calculation Equations for the Brightness and LED Current. Need to take note of something. When we set “Digital ALS Output” to “Logarithmic”, “ALC Backlight Profile” will change to “Logarithmic” synchronously, and you can’t change it to “Linear”. The right block shows "Enable ALS", "ALS Output Offset Test Mode Enable" and "External ALS BIAS Supplied" items. Clicking "Enable ALS" and "ALS Output Offset Test Mode Enable", ALS function will be enabled. Here also provide ALS Fade up/down time select item. Clicking “Read Ambient Level. 08h” button, a read data from external ambient light sensor will appear at the right of the button. “LDO” Sheet Description This sheet lists the AAT2893’s four low dropout linear regulators (LDO) enable and voltage selection .Click "Enable" and select the LDO voltage, then click “Write LDO Register” button to control LDOs. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 15 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Figure 15: LDO Sheet “Register” Sheet Description All of 28 registers listed in this sheet can control the AAT2893 through configuring registers directly. After finishing registers setting, click “Write All Selected Registers” button to send all of registers data to the AAT2893 via I2C, or click “Dump Register Value” to save the current registers configuration. And here also provide a “Read Ambient Level. 08H” button to read the data from external ambient light sensor. Note: 1. All settings, including“Backlight” sheet, “ALS Setup” sheet and “LDO” sheet, can be directly configured by setting the registers in “Registers” sheet. 2. The buttons with highlighed characters mean high level “1”, and the buttons with grey characters mean low level “0”. Clicking Bit7 to Bit0 buttons in column to modify the register data, and inputing the data into “Data” column is another way to modify register data. 3. Register AMLRB (Addr08h) is a read register. It could not input data. 16 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Figure 16: Register Sheet. “Script” Sheet Description The sheet has three buttons of “Load”, “Save” and “Dump” to manage registers data more conveniently. Click “Load” to load registers’ addresses and data that have been saved before. Click “Save” and “Dump” to save the addresses and data of the registers. The difference between “Save” and “Dump” is that clicking “Save” can also save some literalness explanation for each register. Figure 17: Script Sheet. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 17 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs “Log” Sheet Description It is a record sheet. When registers are operated, this page will record the operating time, write/read, register addresses and the register data. These data can be saved, cleared and selectively cleared. Figure 18: “Log” Sheet LDO The AAT2893 provides four channels of Low Dropout Linear Regulator LDOA, B, C and D. Their output voltage can be set from 1.2V to 3.3V via I2C. LDOA can supply up to 300mA, LDOB/C/D can source up to 150mA. LDO building up steps are listed as follows : 4. 5. 6. 7. Configure board and make connections as described in the “Getting started” section. Apply 3.0V ~ 5.5V power to the VIN and GND terminals. Run and operate AAT2892 Windows GUI program to control the AAT2893. Click “Enable” and select “Output Voltage”, then click “Write LDO Registers” in “LDO” sheet of the program. See Figure 15. PWM Dimming 1. 2. 3. 4. 5. 6. 18 Configure board and make connections as described in the “Getting started” section. Apply 3.0V to 5.5V power to VIN and GND terminals. Run and Operate AAT2893 Windows GUI program to control the AAT2893. Click “Enable Backlight LED” to enable LED, and “CABC PWM Input Enable” is default to enable. Adjust “Backlight LED Current” to 28.6mA or a desirable value. Input a PWM wave by signal source. Change LED current by adjusting the duty of the waveform to achieve “PWM dimming control”. Figure 19 shows the relationship between LED current and PWM duty cycle. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Figure 19: Curve of PWM Duty Cycle vs Backlight Current. Test Waveform ALS in Auto Gain Figure 20 shows SBIAS and AMB_IN waveform under the test condition of Auto Gain Mode, VSBIAS = 3.0V, TPOLLING = 0.5s and Gain Resistor Pair = 4k/16k. Figure 20: ALS Polling Waveform. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 19 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs LED Current Variation when ALS Changed Figure 21 shows LED current variation when changing the ambient light sensor under the test conditions of Auto Gain Mode, VSBIAS = 3.0V, TPOLLING = 0.5s, Gain Resistor Pair = 4k/16k and ILED = 28.6mA. Figure 21: LED Current Variation Waveform. Boost PWM Dimming Waveform Figure 22 shows the operating waveform of WLED Driver under the test condition of VIN = 3.6V, 10WLEDs, ILED = 19.8mA and PWM Duty = 30%. (a) PWM Frequency = 1kHz. 20 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs (b) PWM Frequency = 10kHz. Figure 22: WLED Driver PWM Dimming Waveform. Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 21 EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Printed Circuit Board (a) Top Layer (not to scale). (b) Bottom Layer (not to scale). Figure 23: AAT2893 Evaluation Board. BOM of Demo Board Component Part Number U1 AAT2893IUL U2 C1,C2 C3, C4, C8, C9, C10 C5 C6 C7 D1-D10 D11 DS1 L1 P5 R2,R13, R12 R9, R11 R10 BH1600FVC GRM188R60J475K GCM188R70J225KE22 GRM21BR61H225KA73L GRM188R71C563K GRM188R71H103KA01 RS-0805UW SDM20U40 CDRH3D14-4R7NC Chip Resistor Description Manufacturer Ambient Light Control Boost LED Backlight Driver IC with 4 LDOs; WLCSP20 Ambient Light Sensor IC; WSOF6 Cap Ceramic 4.7μF 0603 X5R 6.3V 10% 2.2μF, 6.3V, X7R, 0603 2.2μF, 50V, X7R, 0805 Cap Ceramic 0.056μF 0603 X7R 16V 10% 10nF, 50V, X7R, 0603 30mA White LED 0805 Not populated. Do not solder Surface Mount Schottky Barrier Diode Power Inductor 4.7μH 1.1A SMD 0.1" Header, 2x5 pins 0Ω, 1%, 1/8W; 0402 100kΩ, 1%, 1/4W; 0603 Open, reserved for external Gain Resistor adjust Skyworks Rohm Murata Realstar Diodes Sumida Table 4: AAT2893 Evaluation Board Bill of Materials. 22 Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 Vishay EVALUATION BOARD DATA SHEET EV192 Evaluation Board for the AAT2893 CABC Compatible, Ambient Light Control Boost LED Backlight Driver & Four LDOs Copyright © 2012 Skyworks Solutions, Inc. All Rights Reserved. Information in this document is provided in connection with Skyworks Solutions, Inc. (“Skyworks”) products or services. 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Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [email protected] • www.skyworksinc.com 202324A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • September 3, 2012 23