APW7128 30V, 1.2MHz, White LED Driver Features General Description * * * Wide Input Voltage Range from 2.7V to 21V The APW7128 is the high power and high efficiency boost High Current-Limit up to 3.5A 0.5V Reference Voltage with 3% converter with an integrated 30V FET ideal for LCD panel backlighting applications. 30V output voltage allows for 8 System Accuracy 50m Integrated N-FET high-power LEDs in series, and 3.5A inductor current limit allows for more LED strings connected in parallel. The Fixed 1.2MHz Switching Frequency High Efficiency up to 95% low 0.5V feedback voltage offers higher efficiency in WLED driver applications. The wide input range from 2.7V to Open-LED Protection Under-Voltage Lockout Protection 21V made APW7128 a perfect solution for various applications such as LCD monitor and portable devices. The ALS Control Input Pin Over-Temperature Protection OVP pin monitors the output voltage to protect IC during open load and FB pin short circuit operations. The Low Shutdown Current: <1A 3mmx3mm DFN-10 Package APW7128 provides the ALS pin to simplify the interface to an ambient light sensor for automatic dimming. The Lead Free and Green Devices Available (RoHS Compliant) APW7128 is available in the thermally enhanced DFN-10 lead 3mmx3mm package. * * * * * * * * * * Applications * Pin Configuration APW7128 Display Backlighting - Automotive - LCD Monitors FB COMP OVP EN PGND - Notebook Displays * Portable Displays 1 2 3 4 5 ALS GND BP VIN LX DFN3x3-10 (Top View) Ordering and Marking Information Package Code QA : DFN3x3-10 Operating Ambient Temperature Range I : -40 to 85 oC Handling Code TR : Tape & Reel Assembly Material G : Halogen and Lead Free Device APW7128 Assembly Material Handling Code Temperature Range Package Code APW7128 QA: Metal LX Pad (Bottom) 10 9 8 7 6 APW 7128 XXXXX XXXXX - Date Code Note: ANPEC lead-free products contain molding compounds/die attach materials and 100% matte tin plate termination finish; which are fully compliant with RoHS. ANPEC lead-free products meet or exceed the lead-free requirements of IPC/JEDEC J-STD-020D for MSL classification at lead-free peak reflow temperature. ANPEC defines "Green" to mean lead-free (RoHS compliant) and halogen free (Br or Cl does not exceed 900ppm by weight in homogeneous material and total of Br and Cl does not exceed 1500ppm by weight). ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise customers to obtain the latest version of relevant information to verify before placing orders. Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 1 www.anpec.com.tw APW7128 Absolute Maximum Ratings Symbol (Note 1) Parameter Rating Unit VIN VIN pin to GND -0.3 to 30 V VLX LX pin to PGND -0.3 to 30 V VOVP OVP pin to GND -0.3 to 30 V VBP BP pin to GND -0.3 to 6 V VEN EN pin to GND -0.3 to 30 V VALS ALS pin to GND -0.3 to 6 V PGND to GND TJ TSTG TL Maximum Junction Temperature Storage Temperature Range Maximum Lead Soldering Temperature, 10 Seconds -0.3 to 0.3 V 150 C -65 to 150 C 260 C Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Thermal Characteristics Symbol JA Parameter Junction to Ambient Thermal Resistance in Free Air (Note 2) DFN3x3-10 Typical Value Unit 80 C/W Note 2: JA is measured with the component mounted on a high effective thermal conductivity test board in free air. The exposed pad is soldered directly on the PCB. Recommended Operating Conditions Symbol Range Unit VIN Supply Voltage, (VIN=BP) 2.7 to 5.5 V VIN Supply Voltage, (BP is open) 3.7 to 21V V Output Voltage up to 30 V TJ Operating Ambient Temperature -40 to 85 C TA Operating Junction Temperature -40 to 125 C VIN VOUT Parameter Electrical Characteristics VIN=6V, TA = -40 to 85C, unless otherwise specified. Typical values refer to TA =25C. Symbol Parameter APW7128 Test Conditions Unit Min. Typ. Max. 2.4 2.5 2.6 V - 100 - mV EN=5V, switching - 9 15 mA EN=0V - - 1 A INPUT SUPPLY CURRENT AND UVLO BP Under Voltage Lockout Threshold VIN rising UVLO Hysteresis IVIN VIN Supply Current Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 2 www.anpec.com.tw APW7128 Electrical Characteristics (Cont.) VIN=6V, TA = -40 to 85C, unless otherwise specified. Typical values refer to TA =25C. Symbol Parameter APW7128 Test Conditions Unit Min. Typ. Max. - 350 - ERROR AMPLIFIER gm ICOMP VFB Error Amplifier Transconductance COMP Output Current Minimum FB Voltage IFB sourcing and sinking, VCOMP=1.5V FB Voltage VALS=0.3V FB Input Bias Current FB Line Regulation VIN=2.7V to 21V A/V - 50 - A 485 500 515 mV 188 200 212 mV - - 1 A - 0.02 0.04 %/V 2.5 3.5 4.5 A - 50 100 m - - 1 A INTERNAL POWER SWITCH Power Switch Current-Limit RDS(ON) Power Switch On Resistance LX Leakage Current VLX=30V FSW Switching Frequency 0.9 1.2 1.5 MHz DMAX LX Maximum Duty Cycle 92 95 98 % 2.9 3 3.1 V/V - - 1 A Over-Voltage Threshold 30 32 34 V OVP Hysteresis 2 3 4 V OVP Leakage Current - - 30 A EN High-Level Input Voltage 2.4 - - V EN Low-Level Input Voltage - - 0.4 V - - 1 A - 150 - - ALS ALS Ratio VALS=1V, VALS/VFB ALS Pin Leakage VALS=5V OUTPUT OVER-VOLTAGE PROTECTION CONTROL LOGIC PIN EN Leakage Current VEN=21V THERMAL SHUTDOWN Thermal Shutdown Threshold Thermal Shutdown Hysteresis Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 - 3 50 C C www.anpec.com.tw APW7128 Typical Operating Characteristics VIN Supply Current vs. VIN Supply Voltage VIN Supply Current vs. VIN Supply Voltage 800 9.0 no switching VIN Supply Current (A) VIN Supply Current (mA) 8.5 switching 7.5 6.5 5.5 4.5 700 600 500 3.5 2.5 0 5 10 15 20 400 25 0 5 10 15 20 25 VIN Supply Voltage (V) VIN Supply Voltage (V) FB Voltage vs. VIN Supply Voltage Efficiency vs. Load Current 0.510 100 95 Efficiency (%) VIN=19V FB Voltage (V) VIN=12V 90 VIN=6V 85 80 75 0.505 0.500 0.495 70 65 8LEDs in series 0.490 60 0 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Load Current (A) 5 10 15 20 25 VIN Supply Voltage (V) EN Threshold Voltage vs. VIN Supply Voltage FB Voltage vs. ALS Input Voltage 0.55 2.0 0.50 EN Threshold Voltage (V) FB Voltage (V) 0.45 0.40 0.35 0.30 0.25 0.20 0.15 0 0.5 1 1.5 EN High Threshold 1.6 1.4 EN Low Threshold 1.2 1.0 2 2 ALS Input Voltage (V) Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 1.8 6 10 14 18 22 VIN Supply Voltage (V) 4 www.anpec.com.tw APW7128 Typical Operating Characteristics (Cont.) Switching Frequency vs. VIN Supply Voltage Power Switching On Resistance vs. VIN Supply Voltage 1.40 60 Switching Frequency (MHz) Power Switch On Resistance (m) 70 50 40 30 20 1.35 1.30 1.25 1.20 10 2 6 10 14 18 0 22 5 1.50 800 1.45 750 15 20 25 VIN Supply Current vs. Junction Temperature no switching 700 1.40 VIN Supply Current (A) Switching Frequency (MHz) Switching Frequency vs. Junction Temperature 1.35 1.30 1.25 1.20 1.15 1.10 1.05 650 600 550 500 450 400 350 300 250 1.00 -40 -20 0 200 20 40 60 80 100 120 140 160 -40 -20 0 Junction Temperature ( oC) 20 40 60 80 100 120 140 160 Junction Temperature ( oC) Power Switching On Resistance vs. Junction Temperature FB Voltage vs. Junction Temperature 100 0.510 0.508 80 0.506 FB Voltage (V) Power Switch On Resistance (m) 10 VIN Supply Voltage (V) VIN Supply Voltage (V) 60 40 0.504 0.502 0.500 0.498 0.496 20 0.494 0.492 0 -40 -20 0 0.490 -40 -20 20 40 60 80 100 120 140 160 Junction Temperature ( oC) Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 0 20 40 60 80 100 120 140 160 Junction Temperature (oC) 5 www.anpec.com.tw APW7128 Operating Waveforms Refer to the typical application circuit. The test condition is VIN=5V, TA= 25oC unless otherwise specified. Start-up Shutdown VE N 1 1 VE N VOUT VOUT 2 2 I IN 4 4 VIN=12V, L=10H, CCOMP=0.22F I IN VIN=12V, L=10H, CCOMP=0.22F CH1: VEN, 10V/div, DC CH2: VOUT, 10V/div, DC CH4: IIN, 500mA/div, DC TIME: 10ms/div CH1: VEN, 10V/div, DC CH2: VOUT, 10V/div, DC CH4: IIN, 500mA/div, DC TIME: 1ms/div Over-Voltage Protection Switching Waveforms 1 V COMP 1 2 VOUT 3 2 IIN 4 4 VIN=12V, L=10H, CCOMP=160mA CH1: VIN, 50mV/div, AC Output is open CH1: VCOMP, 0.5V/div, DC CH2: VOUT, 10V/div, DC CH4: IIN, 100mA/div, DC TIME: 10ms/div Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 CH2: VOUT, 200mV/div, AC CH3: VLX, 20V/div, DC CH4: IL, 200mA/div, DC TIME: 0.5s/div 6 www.anpec.com.tw APW7128 Pin Description PIN FUNCTION NO. NAME 1 FB 2 COMP 3 OVP 4 EN 5 PGND 6 LX Internal Power MOSFET Drain. 7 VIN Supply Voltage Input. 8 BP Output of The Internal 5V Regulator. Connect a 1F bypass capacitor to GND. Do not apply an external load to BP. 9 GND Signal Ground. 10 ALS Ambient Light Sensor Input. Allow the light sensor to control the FB voltage for LED dimming. If the ALS function is not used, tie the ALS pin to BP pin. Regulator Feedback Pin. Connect a current sense resistor to GND to set the LED current. Error Amplifier Output. Connect a 0.22F capacitor for compensation and soft-start. When EN is pulled low, an internal switch will discharge the COMP voltage to 0V. Output Over Voltage Monitor Pin. Tie to VOUT for OVP function. Enable Input Pin. Pull EN above 2.4V to enable the device; pull EN below 0.4V to disable the device. The EN pin cannot be left floating. Power Ground. Source of the internal N-channel power MOSFET. Block Diagram BP VIN OVP LDO UVLO 0.9V LX EN Control Logic Thermal Shutdown GND PGND Oscillator FB COMP 0.5V ALS Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 7 www.anpec.com.tw APW7128 Typical Application Circuit 6V to 21V L1 10H D1 C1 10F 10 7 ON 4 9 OFF 8 LX VIN OVP EN COMP GND PGND BP APW7128 C2 1F PWM brightness control Up to 8 LEDs per String 3 2 C3 5 0.22F 1 FB 3V C5 1F 6 ALS Up to 8 Strings R3 120k VADJ 0V R2 24k C4 0.1F R4 10k R1 I =20mA LED(max) 3.75 ILED(min)=0mA Figure1. Analog Dimming with PWM Voltage VDD 6V to 21V L1 10H D1 C1 10F 10 ALS R2 7 ON 4 9 OFF 8 ALS LX VIN OVP EN COMP GND PGND BP APW7128 C2 1F 6 FB Up to 8 Strings C5 1F Up to 8 LEDs per String 3 2 C3 5 0.22F 1 R1 3.125 Figure2. Analog Dimming with External ALS Voltage Designation Supplier L1 GOTREND C1 Part Number Specification Wedsite GTSD53 10H, 1.33A www.gotrend.com.tw Murata GRM31CR61E106K X5R, 25V, 10F www.murata.com C2 Murata GRM155R61A105K X5R, 10V, 1F www.murata.com C3 Murata GRM155R60J224KE01 X5R, 6.3V. 0.22F www.murata.com C5 Murata GRM21BR71H105KA12 X7R, 50V, 1F www.murata.com D1 Zowie MSCD104 1.0A, 40V www.zowie.com.tw Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 8 www.anpec.com.tw APW7128 Function Description Output Over-Voltage Protection Thermal Shutdown If the FB pin is shortened to the ground or an LED fails When the junction temperature exceeds 150C, the inter- open circuit, output voltage in BOOST mode can increase to potentially damaging voltages. An optional over-volt- nal thermal sensor circuit will disable the device and allow the device to cool down. When the device's junction age protection circuit can be enabled by connection of the OVP pin to the output voltage. The device will stop temperature cools by 50C, the internal thermal sense circuit will enable the device, resulting in a pulsed output switching if the output voltage exceeds OVP high threshold and re-start when the output voltage falls below OVP during continuous thermal protection. Thermal protection is designed to protect the IC in the event of over tem- low threshold. During sustained OVP fault conditions, VOUT will saw-tooth between the upper and lower thresh- perature conditions. For normal operation, the junction temperature cannot exceed TJ=+125 C. old voltages at a frequency determined by the magnitude of current available to discharge the output capacitor. Note Internal 5V LDO that the OVP pin must be connected to output voltage for OVP function. The APW7128 provides an internal 5V LDO for the control circuitry, and the output of the internal LDO is BP pin. In Ambient Light Sensor Interface normal operation, connect a 1F or greater capacitor to GND is recommended. The internal LDO cannot supply The APW7128 provides the ALS pin to simplify the inter- any more current than is required to operate the APW7128. Therefore, do not apply any external load to BP pin. In face to an ambient light sensor. The ambient light sensor detects the ambient light and yields a current which is applications, where the VIN is less than 5.5V, BP should be tied to VIN through a 10 resistor. related to the illuminance. Connect a load resistor from the current output of ambient light sensor to ground to provide an output voltage to ALS pin. The ALS voltage will be divided by an internal divider circuit, and the divided ALS voltage will replace the internal reference voltage. The LED current can be calculated by the following equation: ILED = 1 VALS x 3 R1 Note that the maximum FB voltage is set to 0.5V, and minimum FB voltage is set to 0.2V. If the divided ALS voltage is over 0.5V or less 0.2V, the LED current is limited at: ILED(MAX) = 0.5V R1 ILED(MIN) = 0.2V R1 where R1 is the resistor from FB to GND. Enable/Disable Pull the EN above 2V to enable the device and pull EN pin below 0.4V to disable the device. In shutdown mode, the internal control circuits are turned off, the quiescent current is below 1A. Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 9 www.anpec.com.tw APW7128 Application Information Connecting More LED Strings Inductor Selection The APW7128 can drive 8 LED strings in parallel and up A larger value of inductor will reduce the peak inductor to 8 LEDs per string (VF<3.5V). Each string must have the same number of LEDs. In the applications that have the current, resulting in smaller input ripple current, higher efficiency and reducing stress on the internal MOSFET. same total number of LEDs, more strings and less LEDs in series are more efficiency than less strings and more However, the larger value of inductor has a large dimension, lower saturation current, and higher series LEDs in series. resistance. A good rule for determining the inductance is to allow the Brightness Control peak-to-peak ripple current to be approximately 30% to 50% of the maximum input current. Calculate the required The method for dimming the LEDs is to apply a PWM voltage through an RC filter into the FB pin. The RC filter is used to convert the PWM voltage into an inductance value by the equation: L = ( V - V )x V I x F x V OUT analog voltage. The values of the R and C depend upon the frequency of the PWM voltage and the amount of al- L IN SW IN OUT IL = (30% - 50%) x IIN lowable ripple voltage on FB pin. The LED current is proportional to the PWM duty cycle. 0 % duty delivers maxi- IIN = VOUTxILOAD VIN x mum LED current and 100% duty delivers minimum LED current. The values of R1 and R2 are calculated by the It is necessary to choose an inductor that ensures the following equations: inductor saturation current rating to exceed the peak inductor current for the application. R2 = R1 = VFB x (ILED(max) x R3 + VADJ(low) - ILED(min) x R3 - VADJ(high)) VADJ(high) x ILED(max) + VFB x ILED(min) - VADJ(low) x ILED(min) - VFB x ILED(max) V FB x (1 + To make sure that the peak inductor current is below the current-limit 2.5A. Calculating the peak inductor current by the following equation: R2 R2 x V ADJ ( low ) )- R3 R3 I IPEAK = IIN + 0.5 x IL LED (max) IPEAK = where: ILED(max) is the maximum LED current ILED(min) is the minimum LED current VOUT x ILOAD ( VOUT - VIN) x VIN + VIN x 2 x L x FSW x VOUT where is the efficiency VADJ(high) is the maximum PWM voltage level VADJ(low) is the minimum PWM voltage level Schottky Diode Selection VFB is the FB pin Voltage A fast recovery time and low forward voltage Schottky diode is necessary for optimum efficiency. Ensure that the diode's average and peak current rating exceed the average output current and peak inductor current. In addition, the diode's reverse voltage must exceed output voltage. APW7128 FB 1 Capacitor Selection R2 VADJ(high) PWM Voltage R1 An input capacitor is required to supply the ripple current R3 R4 to the inductor and stabilize the input voltage. Larger input capacitor values and lower ESR provide smaller C4 input voltage ripple and noise. The typical value for input capacitor is 2.2F to 10F. VADJ(low) Figure 3. Dimming with the PWM Voltage Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 10 www.anpec.com.tw APW7128 Application Information (Cont.) Capacitor Selection (Cont.) VIN The output capacitor with typical value 1F to 10F is re- L1 D1 C1 C4 quired to maintain the output voltage. The COMP capacitor with typical value 0.22F to 1F stabilizes the con- LX VIN COMP verter and controls the soft-start. To ensure the voltage rating of input and output capaci- C3 tors is greater than the maximum input and output voltage. It is recommended using the ceramic capacitors with X5R, C2 FB BP X7R, or better dielectrics for stable operation over the entire operating temperature range. BOTTOM SIDE PAD GN PGN D D R1 Via connection to PGND plane Layout Consideration Via connection to GND plane The correct PCB layout is important for all switching converters. If the layout is not carefully done, the regulator Via connection to LX plane Short and wide wires could show stability problems as well as EMI problems. Figure. 4 illustrates the layout guidelines; the bold lines Short wires indicate these traces that must be short and wide. The capacitors, the diode, and the inductor should be as close Figure 4. Layouy Guidelines to the IC as possible. Keep traces short, direct, and wide. Keep the LX node away from FB and COMP pins. The trace from diode to the LEDs may be longer. The ground return of input capacitor and output capacitor should be tied close to PGND. Use the different ground planes for signal ground and power ground to minimize the effects of ground noise. Connect these ground nodes at any place close to one of the ground pins of the IC. The resistor from FB to GND should be close to the FB pin as possible. The metal plate of the bottom must be soldered to the PCB and connected to LX node and the LX plane on the backside through several thermal vias to improve heat dissipation. Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 11 www.anpec.com.tw APW7128 Package Information DFN3x3-10 D E A Pin 1 A1 D2 A3 L K E2 Pin 1 Corner e S Y M B O L DFN3x3-10 MILLIMETERS INCHES MIN. MAX. MIN. MAX. A 0.80 1.00 0.031 0.039 A1 0.00 0.05 0.000 0.002 0.30 0.007 0.012 0.122 A3 b 0.20 REF 0.18 0.008 REF D 2.90 3.10 0.114 D2 2.20 2.70 0.087 0.106 E 2.90 3.10 0.114 0.122 1.75 0.055 0.069 E2 1.40 e 0.50 BSC L 0.30 K 0.20 0.020 BSC 0.012 0.50 0.020 0.008 Note : 1. Followed from JEDEC MO-229 VEED-5. Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 12 www.anpec.com.tw APW7128 Carrier Tape & Reel Dimensions P0 P2 P1 A B0 W F E1 OD0 K0 A0 A OD1 B B T SECTION A-A SECTION B-B H A d T1 Application DFN3x3-10 A H T1 C d D W E1 F 3302.00 50 MIN. 12.4+2.00 -0.00 13.0+0.50 -0.20 1.5 MIN. 20.2 MIN. 12.00.30 1.750.10 5.50.05 P0 P1 P2 D0 D1 T A0 B0 K0 4.00.10 8.00.10 2.00.05 1.5+0.10 -0.00 1.5 MIN. 0.6+0.00 -0.40 3.300.20 3.300.20 1.300.20 (mm) Devices Per Unit Package Type Unit Quantity DFN3x3-10 Tape & Reel 3000 Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 13 www.anpec.com.tw APW7128 Taping Direction Information DFN3x3-10 USER DIRECTION OF FEED Classification Profile Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 14 www.anpec.com.tw APW7128 Classification Reflow Profiles Profile Feature Sn-Pb Eutectic Assembly Pb-Free Assembly 100 C 150 C 60-120 seconds 150 C 200 C 60-120 seconds 3 C/second max. 3C/second max. 183 C 60-150 seconds 217 C 60-150 seconds See Classification Temp in table 1 See Classification Temp in table 2 Time (tP)** within 5C of the specified classification temperature (Tc) 20** seconds 30** seconds Average ramp-down rate (Tp to Tsmax) 6 C/second max. 6 C/second max. 6 minutes max. 8 minutes max. Preheat & Soak Temperature min (Tsmin) Temperature max (Tsmax) Time (Tsmin to Tsmax) (ts) Average ramp-up rate (Tsmax to TP) Liquidous temperature (TL) Time at liquidous (tL) Peak package body Temperature (Tp)* Time 25C to peak temperature * Tolerance for peak profile Temperature (Tp) is defined as a supplier minimum and a user maximum. ** Tolerance for time at peak profile temperature (tp) is defined as a supplier minimum and a user maximum. Table 1. SnPb Eutectic Process - Classification Temperatures (Tc) Package Thickness <2.5 mm 2.5 mm Volume mm <350 235 C 220 C 3 Volume mm 350 220 C 220 C 3 Table 2. Pb-free Process - Classification Temperatures (Tc) Package Thickness <1.6 mm 1.6 mm - 2.5 mm 2.5 mm Volume mm <350 260 C 260 C 250 C 3 Volume mm 350-2000 260 C 250 C 245 C 3 Volume mm >2000 260 C 245 C 245 C 3 Reliability Test Program Test item SOLDERABILITY HOLT PCT TCT HBM MM Latch-Up Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 Method JESD-22, B102 JESD-22, A108 JESD-22, A102 JESD-22, A104 MIL-STD-883-3015.7 JESD-22, A115 JESD 78 15 Description 5 Sec, 245C 1000 Hrs, Bias @ Tj=125C 168 Hrs, 100%RH, 2atm, 121C 500 Cycles, -65C~150C VHBM2KV VMM200V 10ms, 1tr100mA www.anpec.com.tw APW7128 Customer Service Anpec Electronics Corp. Head Office : No.6, Dusing 1st Road, SBIP, Hsin-Chu, Taiwan, R.O.C. Tel : 886-3-5642000 Fax : 886-3-5642050 Taipei Branch : 2F, No. 11, Lane 218, Sec 2 Jhongsing Rd., Sindian City, Taipei County 23146, Taiwan Tel : 886-2-2910-3838 Fax : 886-2-2917-3838 Copyright ANPEC Electronics Corp. Rev. A.2 - Aug., 2010 16 www.anpec.com.tw