APL3555 USB Power-Distribution Switches Features General Description • 62mΩ Power Switch On Resistance • Wide Supply Voltage Range: 2.7V to 5.5V The APL3555 series of power switches are designed for USB applications. The 62mΩ N-channel MOSFET power • Fix Current Limit Protection • Fast Over current Response: 2us (typ.) • Over-Temperature Protection • Fault Indication Output • Enable Input • Built-in Soft-Start switch satisfies the voltage drop requirements of USB specification. The protection features include current-limit protection, short-circuit protection, and over-temperature protection. The device limits the output current at current limit threshold level. When VOUT drops below VIN-1V, the devices limit the current to a lower and safe level. The over-temperature protection limits the junction temperature below 140oC in case of short circuit or over load conditions. Other features include a deglitched OCB output to indicate the fault condition and an enable input to enable or disable the device. Applications • • Notebook and Desktop Computers • High-Side Power Protection Switchs • MHL Ports Simplified Application Circuit USB Ports 5V USB Port VIN VOUT APL3555A/B/C/D USB Controller OCB EN/ENB GND Pin Configurations VOUT 1 5 VIN GND 2 OCB 3 4 EN SOT-23-5 APL3555A/C (Top View) VOUT 1 5 VIN GND 2 OCB 3 4 ENB SOT-23-5 APL3555B/D (Top View) 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.1 - Mar., 2016 1 www.anpec.com.tw APL3555 Ordering and Marking Information Package Code B : SOT-23-5 Operating Ambient Temperature Range Assembly Material I : -40 to 85 oC Handling Code Handling Code TR : Tape & Reel Temperature Range Output Current/EN Function Package Code A : 2A/Active High B : 2A/Active Low C : 1A/Active High Output Current/EN Function D : 1A/Active Low Assembly Material G : Halogen and Lead Free Device APL3555 APL3555Ο B: L5ΟX Ο-Output Current/EN Function Code X - 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). Absolute Maximum Ratings Symbol VIN VOUT VENB, VEN VOCB TJ (Note 1) Parameter Rating Unit VIN Input Voltage (VIN to GND) -0.3 ~ 7 V VOUT to GND Voltage -0.3 ~ 7 V EN, ENB to GND Voltage -0.3 ~ 7 V OCB to GND Voltage -0.3 ~ 7 Maximum Junction Temperature TSTG Storage Temperature TSDR Maximum Lead Soldering Temperature, 10 Seconds V 150 o -65 ~ 150 o 260 o C C C Note1: Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Thermal Characteristics Symbol θJA Pa ram ete r Junctio n-to-Amb ient Resistance in Fr ee A ir Typica l Value (N ote 2) Unit o S OT-2 3-5 23 5 C/W Note 2 : θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. Recommended Operating Conditions (Note 3) Sym bol VIN I OUT Pa ra mete r V IN In put Vol tag e Range Unit 2.7 ~ 5.5 V O UT Output Curren t (AP L355 5A/B) 0 ~2 O UT Output Curren t (AP L355 5C/D) 0 ~1 A TA A mbient Temp erature -40 ~ 85 o TJ Jun ction Temper ature -4 0 ~ 125 o C C Note 3 : Refer to the typical application circuit Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 2 www.anpec.com.tw APL3555 Electrical Characteristics Unless otherwise specified, these specifications apply over VIN=5V, VEN =5V or VENB=0V and TA= -40 ~ 85 oC. Typical values are at TA=25oC. Sym bol Param ete r APL35 55 Te st Conditions Min. Unit Typ. Max . SUPPLY CURRENT µA No lo ad, V EN=0 V or V ENB=5V - - 1 No lo ad, V EN=5 V or V ENB=0V - 65 - µA Lea ka ge Curren t VOUT=GND, VEN=0V or VENB=5V - - 1 µA Reverse Leaka ge Current VIN=GND, VOUT =5 V, V EN =0V o r V ENB=5V - - 1 µA I OUT =1.5A, o T A= 2 5 C - 62 78 mΩ 1.7 - 2 .6 5 V - 0.2 - V APL3 555A /B VIN=2 .7V to 5.5V, T A= 2 5 o C 2.1 2.5 2.9 A APL3 555C/D o VIN=2 .7V to 5.5V, T A= 2 5 C 1.1 1.5 1.9 A - 0.8 - A - 0.8 - A - 0.2 0.4 V - - 1 µA OCB asse rtio n, T A= -40 ~ 8 5 C 5 12 20 ms 2 - - V VIN Suppl y Curren t POWER SWITCH R DS(ON) Po wer S witch On Resistan ce S OT-2 3-5 Package UNDE R-VOLTAGE LOCKOUT (UVLO) VIN UVL O Thr eshold Voltage V IN risin g, T A= -40 ~ 85 o C VIN UVL O Hysteresis CURRENT- LIMIT AND SHORT-CIRCUIT PROTECTIONS ILIM I SHORT Curren t Limit Th reshold Sho rt- Ci rcu it Ou tpu t Curre nt APL3 555A /B VIN=2 .7V to 5.5V APL3 555C/D VIN=2 .7V to 5.5V OCB OUTPUT PIN t D(OC B) OCB Outpu t Lo w Voltage IOCB=5mA OCB Le akage Curren t VOCB=5V OCB Deglitch Time o EN OR ENB INPUT PIN VIH In put Logic HIG H VIN=2 .7V to 5V VIL In put Logic LOW VIN=2 .7V to 5V In put Cu rrent VOUT Dischar ge Resistance VEN=0V or VENB=5V - - 0.8 V - - 1 µA - 1 50 - Ω t D(ON ) Tu rn On Delay Time - 80 - µs t D(OFF) Tu rn Off De lay Time - 5 - µs No lo ad, C OUT =1µF, VIN=5V - 4 00 10 00 µs TJ rising - 1 40 - °C - 20 - °C tSS Soft-Start Time OVER-TEMPERATURE PROTECTION (OTP) T OTP Over-Temp erature Thresho ld Over-Temp erature Hystere sis Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 3 www.anpec.com.tw APL3555 Typical Operating Characteristics Switch On Resistance vs. Junction Temperature Switch On Resistance vs. Input Voltage 110 130 VIN=5V IOUT=1.5A CIN=10µF COUT =10µF Switch On Resistance, RDS(on) (mΩ) Switch On Resistance, RDS(on) (mΩ) 130 90 70 50 -50 -10 30 70 110 Junction Temperature ( OC) 110 90 70 50 2.5 150 IOUT =1.5A CIN=10µF COUT =10µF TA=25OC 3 3 .5 4 4.5 5 5.5 Input Voltage (V) Supply Current vs. Input Voltage Supply Current vs. Junction Temperature 120 120 110 Supply Current, ICC (µA) Supply Current, ICC (µA) 100 80 60 40 VIN=5V RLOAD=OPEN CIN=10µF COUT=10µF 20 -10 30 70 O 110 90 80 RLOAD=OPEN CIN=10µF COUT =10µF TA=25OC 70 60 50 2 .5 0 -50 100 150 3 Junction Temperature ( C) Current Limit Threshold vs . Junction Temperature 3.0 Current Limit Threshold, ILIM (A) Current Limit Threshold, ILIM (A) 3 2 1 VIN=5V 0 -50 -10 30 70 110 Junction Temperature (OC) Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 3 .5 4 4.5 5 5.5 Input Voltage (V) 2.9 2.8 2.7 2.6 O TA=25 C 2.5 2.5 150 Current Limit Threshold vs . Input Voltage 3 3.5 4 4.5 5 5.5 Input Voltage (V) 4 www.anpec.com.tw APL3555 Typical Operating Characteristics (Cont.) Current-Limit Response vs. Output Peak Current 2 VIN=5V TA=25OC 200 EN Pin Threshold Voltage, VEN (V) Current-Limit Response (µs) 250 EN Pin Threshold Voltage vs . Junction Temperature 150 100 50 0 EN Rising 1 .6 1.2 EN Falling 0 .8 0 .4 0 0 2 4 6 8 10 VIN=5V RLOAD=50Ω CIN=10µF COUT=10µF 12 -50 Output Peak Current (A) Turn-Off Leakage Current vs. Junction Temperature -10 30 70 110 Junction Temperature (OC) 70 OCB Deglitch Time, T D(OCB) (ms) 8 VIN=5V RLOAD=1Ω CIN=10µF COUT =10µF 4 100 -10 30 70 2.5 UVLO Falling 1 .5 IOUT =15mA CIN=10µF COUT=10µF 0.5 -50 -10 30 70 110 Junction Temperature (OC) Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 5 150 Turn-Off Falling Time vs . Junction Temperature VIN=5V RLOAD=30Ω CIN=10µF COUT =1µF 80 60 40 20 0 -50 150 110 Junction Temperature (OC) ULVO Rising 1 150 12 UVLO Threshold Voltage vs . Junction Temperature 2 110 16 0 -50 150 Turn-Off Falling Time, tF (µs) Turn-Off Leakage Current, ILEAK (µA) 1 3 UVLO Threshold Voltage, VUVLO (V) VIN=5V RLOAD=0Ω CIN=10µF COUT =10µF SD mode 2 0 -50 30 Junction Temperature (OC) OCB Deglitch Time vs. Junction Temperature 4 3 -10 -10 30 70 110 Junction Temperature (OC) 150 www.anpec.com.tw APL3555 Typical Operating Characteristics (Cont.) Turn-On Rising Time, tR (µs) 700 Turn-On Rising Time vs . Junction Temperature 600 500 400 300 V IN=5V RLOAD=30Ω CIN=10µF COUT =1µF 200 100 0 -50 -10 30 70 110 Junction Temperature (OC) Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 150 6 www.anpec.com.tw APL3555 Operating Waveforms Turn Off Response Turn On Response VENB VOUT 2 VENB 1 1 VOUT 2 VIN=5V,C OUT=10µ F/Electrolytic, C IN=10 µF/Electrolytic,R LOAD=30Ω CH1:V ENB,5V/Div, DC CH2:V OUT,2V/Div, DC TIME:200 µs/Div VIN=5V,C OUT=10µ F/Electrolytic, C IN=10 µF/Electrolytic,R LOAD=30Ω CH1:V ENB,5V/Div, DC CH2:V OUT,2V/Div, DC TIME:100µ s/Div UVLO at Rising UVLO at Falling VIN V IN 1 1 V OUT 2 2 VIN=5V,C OUT=10µ F/Electrolytic, C IN=10 µF/Electrolytic,R LOAD=30Ω CH1:V IN,1 V/Div, DC CH2:V OUT,1V/Div, DC TIME:4ms/Div Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 VOUT VIN=5V,C OUT=10µF/Electrolytic, C IN=10 µF/Electrolytic,R LOAD=30Ω CH1:V IN,1V /Div, DC CH2:V OUT,1V/Div, DC TIME:4ms/Div 7 www.anpec.com.tw APL3555 Operating Waveforms (Cont.) OCB Response During Over Load OCB Response During Short Circuit 1 VENB 1 VOCB VOCB 2 2 3 VENB IOUT IOUT 3 VIN=5V,C OUT=10µF/Electrolytic, C IN=10 µF/Electrolytic,R LOAD=0Ω CH1:V ENB,5V/Div, DC CH2:V OCB,5 V/Div, DC CH3:I OUT ,1 A/Div, DC TIME:4ms/Div VIN=5V,C OUT=10µF/Electrolytic, C IN=10 µF/Electrolytic,R LOAD=1Ω CH1:V ENB,5V/Div, DC CH2:V OCB,5V /Div, DC CH3:I OUT ,1A /Div, DC TIME:4ms/Div Load-Transient Response OCB Response with Ramped Load VOCB VOUT 2 VOUT 1 1 3 IOUT 2 VIN=5V,COUT =10µF/Electrolytic, C IN=10µF/Electrolytic CH1:VOUT ,5V/Div, DC CH2:VOCB,5V/Div, DC CH3:I OUT,1A/Div, DC TIME:2ms/Div Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 IOUT V IN=5V ,C OUT =10 µF/Electrolytic, C IN=10µ F/Electrolytic,IOUT =0 to 2A CH1:VOUT ,1 V/Div, DC CH2:IOUT ,1A/Div, DC TIME:2 µs/Div 8 www.anpec.com.tw APL3555 Pin Description PIN FUNCTIO N NO. NAME 2 GND Gro und. 5 VIN Po wer S uppl y Input. Con nect this pi n to external DC sup ply. EN (A/C) En able Input. Pu lling th is pin to hig h will ena ble th e d evice and pu lling this pin to lo w wi ll d isa ble device. The EN pin canno t be left floating. ENB (B/D) En able Input. Pu lling th is pin to hig h will disabl e the device and pullin g this pin to low will ena ble device. The ENB pin can not be l eft floa ting . 3 OCB Fault Ind ica tio n P in. This pi n g oes low whe n a curr ent limit o r an over-temp erature condi tion is d ete cted afte r a 1 2ms de glitch time. 1 VO UT 4 Ou tp ut Vo lta ge Pin. Th e output voltage foll ows the input vo ltage. Wh en ENB is h igh or EN i s low, the outpu t voltage is disch arged b y an intern al resistor . Block Diagram VIN VOUT UVLO Charge Pump EN/ ENB Short-Circuit Protection Current Limit Gate Driver and Control Logic OCB GND OTP Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 9 www.anpec.com.tw APL3555 Parameter Measurement Information POR VIN 0V EN 0V 90%VOUT VOUT>1.5V VOUT 0V TD(ON) TSS 80us 400us IOUT OCB Current Limit 0A high high low NO TD(OCB) TIOS 2us TD(OCB) 12ms Figure 1. Sequence of Power On & Current Limit & OCB Indicate Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 10 www.anpec.com.tw APL3555 Typical Application Circuit USB Port 3.3V 5V CIN 50kΩ 10µF USB Controller VIN VOUT APL3555A/B/C/D COUT 10µF VBUS D+ D- OCB GND EN/ENB GND Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 11 www.anpec.com.tw APL3555 Function Description VIN Under-Voltage Lockout (UVLO) Enable/Disable The APL3555 series of power switches have a built-in Pull the ENB above 2V or EN below 0.8V will disable the device, and pull ENB pin below 0.8V or EN above 2V will under-voltage lockout circuit to keep the output shutting off until internal circuitry is operating properly. The UVLO enable the device. When the IC is disabled, the supply current is reduced to less than 1µA. The enable input is circuit has hysteresis and a de-glitch feature so that it will typically ignore undershoot transients on the input. When compatible with both TTL and CMOS logic levels. The EN/ENB pin cannot be left floating. input voltage exceeds the UVLO threshold, the output voltage starts a soft-start to reduce the inrush current. Over-Temperature Protection Power Switch The power switch is an N-channel MOSFET with a low When the junction temperature exceeds 140oC, the internal thermal sense circuit turns off the power FET and RDS(ON). The internal power MOSFET does not have the body diode. When IC is off, the MOSFET prevents a cur- allows the device to cool down. When the device’s junction temperature cools by 20 oC, the internal thermal rent flowing from the VOUT back to VIN and VIN to VOUT. sense circuit will enable the device, resulting in a pulsed output during continuous thermal protection. Thermal Current-Limit Protection protection is designed to protect the IC in the event of over temperature conditions. For normal operation, the The APL3555 series of power switches provide the current-limit protection function. During current limit, the de- junction temperature cannot exceed TJ=+125oC. vices limit output current at current limit threshold. For reliable operation, the device should not be operated in current limit for extended period. Short-Circuit Protection When the output voltage drops below VIN-1V, which is caused by an over-load or a short-circuit, the devices limit the output current down to a safe level. The short-circuit current limit is used to reduce the power dissipation during short-circuit conditions. If the junction temperature reaches over-temperature threshold, the device will enter the thermal shutdown. OCB Output The APL3555 series of power switches provide an opendrain output to indicate that a fault has occurred. When any of current-limit or over-temperature protection occurs for a deglitch time of tD(OCB), the OCB goes low. If fault condition release, OCB will goes high when VOUT > 1.5V (see Figure 1). Since the OCB pin is an open-drain output, connecting a resistor to a pull high voltage is necessary. Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 12 www.anpec.com.tw APL3555 Application Information Input Capacitor A 1µF or higher ceramic bypass capacitor from VIN to GND, located near the APL3555, is strongly recommended to suppress the ringing during short circuit fault event. When the load current trips the SCP threshold in an over load condition such as a short circuit, hot plug-in or heavy load transient the IC immediately turns off the internal power switch that will cause VIN ringing due to the inductance between power source and VIN. Without the bypass capacitor, the output short may cause sufficient ringing on the input to damage internal control circuitry. Input capacitor is especially important to prevent VIN from ringing too high in some applications where the inductance between power source to VIN is large (ex, an extra bead is added between power source line to VIN for EMI reduction), additional input capacitance may be needed on the input to reduce voltage overshoot from exceeding the absolute maximum voltage of the device during over load conditions. Output Capacitor A low-ESR 10µF aluminum electrolytic or tantalum between VOUT and GND is strongly recommended to reduce the voltage droop during hot-attachment of downstream peripheral. (Per USB 2.0, output ports must have a minimum 120µF of low-ESR bulk capacitance per hub). Higher-value output capacitor is better when the output load is heavy. Layout Consideration The PCB layout should be carefully performed to maximize thermal dissipation and to minimize voltage drop, droop and EMI. The following guidelines must be considered: 1. Please place the input capacitors near the VIN pin as close as possible. 2. Output decoupling capacitors for load must be placed near the load as close as possible for decoupling highfrequency ripples. 3. Locate APL3555 and output capacitors near the load to reduce parasitic resistance and inductance for excellent load transient performance. 4. The negative pins of the input and output capacitors and the GND pin must be connected to the ground plane of the load. 5. Keep VIN and VOUT traces as wide and short as possible. Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 13 www.anpec.com.tw APL3555 Package Information SOT-23-5 D e E E1 SEE VIEW A b c 0.25 GAUGE PLANE SEATING PLANE aaa C L 0 A1 NX A A2 e1 VIEW A S Y M B O L SOT-23-5 MILLIMETERS MIN. INCHES TYP MAX. 1.16 1.45 0.00 0.05 0.15 A2 0.90 1.10 1.30 b 0.30 0.38 0.50 c 0.08 0.17 0.22 D 2.70 2.93 E 2.60 MIN. TYP. MAX. 0.046 0.057 0.000 0.002 0.006 0.035 0.043 0.051 0.012 0.015 0.020 0.003 0.007 0.009 3.10 0.106 0.115 0.122 2.83 3.00 0.102 0.111 0.118 E1 1.60 1.80 0.055 0.063 0.071 e 0.95 BSC 0.037BSC e1 1.90 BSC 0.075BSC A A1 K 0.30 0.45 0.60 0.012 0.018 0.024 0 0 4 8 0 4 8 aaa 0.10 0.004 Note : 1. Follow JEDEC TO-178 AA. 2. Dimension D and E1 do not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 10 mil per side. Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 14 www.anpec.com.tw APL3555 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 SOT- 23-5 A H T1 C d D W E1 F 178.0±2.00 50 MIN. 8.4+2 .0 0 -0.00 13.0+0 .5 0 - 0.2 0 1 .5 MIN. 2 0.2 MIN. 8.0±0.30 1.75±0.10 3.5±0.05 P0 P1 P2 D0 D1 T A0 B0 K0 2.0±0.05 1.5+0.10 -0.00 1 .0 MIN. 0 .6 +0.00 -0 .4 0 3.2 0±0.20 3.10 ±0 .2 0 1.50±0.20 4.0±0.10 4.0 ±0.1 0 (mm) Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 15 www.anpec.com.tw APL3555 Devices Per Unit Package Type Unit Quantity SOT-23-5 Tape & Reel 3000 Taping Direction Information SOT-23-5 USER DIRECTION OF FEED Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 16 www.anpec.com.tw APL3555 Classification Profile 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. 3°C/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 5°C 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 25°C 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. Copyright ANPEC Electronics Corp. Rev. A.1 - Mar., 2016 17 www.anpec.com.tw APL3555 Classification Reflow Profiles (Cont.) 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 Method JESD-22, B102 JESD-22, A108 JESD-22, A102 JESD-22, A104 MIL-STD-883-3015.7 JESD-22, A115 JESD 78 Description 5 Sec, 245°C 1000 Hrs, Bias @ Tj=125°C 168 Hrs, 100%RH, 2atm, 121°C 500 Cycles, -65°C~150°C VHBM≧2KV VMM≧200V 10ms, 1tr≧100mA 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.1 - Mar., 2016 18 www.anpec.com.tw