Product Specification Low-cost Green-Mode PWM Controller for Flyback Converters FEATURES Green-mode PWM Controller Low Start-up Current (5uA) Low Operating Current (3mA) Programmable PWM Frequency Peak-current-mode Operation Leading-edge Blanking Built-in Synchronized Slope Compensation Cycle-by-cycle Current Limiting Constant Output Power Limit Gate Output Voltage Clamped at 15V Small SOT-26 Package Available APPLICATIONS General-purpose switching mode power supplies and flyback power converters, such as Battery chargers Power adapters Open-frame SMPS Replacements for linear transformers and RCC 5V standby power for PC power supply. SG6848x1 DESCRIPTION This highly integrated PWM controller provides several special enhancements designed to meet the low standby-power needs of low-power SMPS. To minimize standby power consumption, the proprietary green-mode function provides off-time modulation to continuously decrease PWM frequency under light-load conditions. This green-mode function enables the power supply to easily meet even the strictest power conservation requirements. The BiCMOS fabrication process enables reducing the start-up current to 5uA, and the operating current to 3mA. As a result, a large start-up resistance can be used. Built-in synchronized slope compensation ensures the stability of peak-current-mode control. Proprietary internal compensation provides a constant output power limit over a universal AC input range (90VAC to 264VAC). Cycle-by-cycle current limiting ensures safe operation during short-circuits. To protect the external power MOSFET from being damaged by supply over voltage, the SG6848x1’s output driver is clamped at 15V. The SG6848x1’s controllers can be used to improve the performance and reduce the production cost of power supplies. The SG6848x1 is the best choice for replacing linear and RCC power supplies. It is available in DIP-8 and SOT-26 packages. TYPICAL APPLICATION © System General Corp. Version 1.3(IAO33.0002.B4) -1- www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters MARKING DIAGRAMS PIN CONFIGURATION SOT-26 XXX:AAH =SG6848T1 XXX:AAH =SG6848TZ1 M: Mask Version W: Week code A~Z=W1~W26 A~Z=W27~W52 :Lead free package XXXMW 1 GND 1 6 GATE FB 2 5 VDD RI 3 4 SENSE 8 DIP-8 D: D = DIP P : Z = Lead Free Null = Regular Package M: Mask Version XXXXXX: Wafer Lot YY: Year; WW: Week V: Assembly Location SG6848DP1 MXXXXXXYYWWV 1 GATE 1 8 GND VDD 2 7 FB NC 3 6 NC SENSE 4 5 RI ORDERING INFORMATION Part Number Package SG6848T1 SOT-26 SG6848D1 DIP-8 SG6848TZ1 SOT-26 (Lead Free) SG6848DZ1 DIP-8 (Lead Free) PIN DESCRIPTIONS Name Pin No. DIP-8 / (SOT-26) Type Function GATE 1 / (6) Driver Output The totem-pole output driver for driving the power MOSFET. VDD 2 / (5) Supply Power supply. NC 3 No connection. Current sense. This pin senses the voltage across a resistor for peak-current-mode SENSE 4 / (4) Analog Input control. If the voltage reaches the internal threshold, PWM output is disabled. This activates cycle-by-cycle current limiting. A resistor connected from the RI pin to GND pin will generate a constant current source RI 5 / (3) Analog Input/Output for the controller. This current is used to determine PWM frequency. Increasing the resistance will reduce PWM frequency. A 95kΩ resistor results in a 70kHz PWM frequency. NC 6 No connection. FB 7 / (2) Analog Input GND 8 / (1) Supply © System General Corp. Version 1.3(IAO33.0002.B4) Feedback. The FB pin accepts the output voltage regulation signal. It provides feedback to the internal PWM comparator to adjust the duty cycle. Ground. -2- www.sg.com.tw Jan. 27, 2006 Product Specification Low-cost Green-Mode PWM Controller for Flyback Converters SG6848x1 BLOCK DIAGRAM © System General Corp. Version 1.3(IAO33.0002.B4) -3- www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters ABSOLUTE MAXIMUM RATINGS Symbol Parameter Value Unit VDD DC Supply Voltage 25 V VFB Input Voltage to FB Pin -0.3 to 6 V V VSENSE Input Voltage to Sense Pin -0.3 to 6V V PD Power Dissipation RθJA Thermal Resistance (Junction to Air) TJ Operating Junction Temperature TSTG Storage Temperature Range TR Peak Reflow Temperature 300 mW SOT-26 208.4 °C/W DIP-8 82.5 °C/W -40 to +125 °C -55 to +150 °C Pb free 260(+5/-0) Pb 230(+5/-0) °C * All voltage values, except differential voltages, are given with respect to GND pin. * Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. RECOMMENDED OPERATING JUNCTION TEMPERATURE: -30°C ~ 105°C* *For proper operation ELECTRICAL CHARACTERISTICS (VDD=15V, TA = 25°C, unless noted) VDD Section Symbol Parameter VOP Continuously Operating Voltage Test Condition Min. Typ. Max. Unit 20 V VTH(ON) Start-up Threshold Voltage 15.3 16.3 17.3 V VDD(MIN) Min. Operating Voltage 10.9 11.7 12.5 V IDD ST Start-up Current IDD OP Operating Supply Current VDD-OVP Over Voltage Protection 5 30 uA 3 5 mA 22 23.5 25 V Min. Typ. Max. GATE = 1nF Feedback Input Section Symbol Parameter ZFB Input Impedance Test Condition IOZ Zero-duty-cycle Input Current 1.3 VOP Open Loop Voltage 4.5 2 Unit kΩ 2.0 mA V Oscillator Section Symbol Parameter Test Condition Min. Typ. Max. FOSC PWM Frequency RI = 95kΩ 65 70 75 Unit FOSC-GREEN Green-mode Min. Frequency RI = 95kΩ FDY Frequency Variation versus VDD Deviation VDD = 14 to 20V 2 % FDT Frequency Variation versus Temp. Deviation TA = -30 to 105 ℃ 2 % kHz 15 kHz IN Green-mode Start Threshold FB Input Current 1 IG Green-mode Min. Freq. FB Input Current 1.16 mA SG Green-mode Modulation Slope 300 Hz/uA RI RI pin resistance © System General Corp. Version 1.3(IAO33.0002.B4) RI = 95kΩ 66.5 -4- mA 150 kΩ www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters Current Sense Section Symbol Parameter ZCS Input Impedance Test Condition Min. Typ. Max. TPD Delay to Output 100 nsec VTH,FLT Current Limit Flatten Threshold Voltage 0.96 V VTH,VALLEY Current Limit Valley Threshold Voltage 0.81 V DCSAW Duty Cycle of SAW Limit 45 % 10 Unit kΩ Gate Section Symbol Parameter DC (MAX) Maximum Duty Cycle DC (MIN) Minimum Duty Cycle BNK Leading-edge Blanking Time VOL Output Voltage Low Sink current = 20mA VOH Output Voltage High Source current = 20mA 8 TR Rising Time GATE = 1nF 250 TF Falling Time GATE = 1nF 80 VCLAMP Output Clamp Voltage VDD = 20V 15 © System General Corp. Version 1.3(IAO33.0002.B4) Test Condition Min. Typ. Max. Unit 70 75 80 % 0 % 200 -5- nsec 1.5 V V nsec nsec 17 V www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters TYPICAL CHARACTERISTICS Min. Operating Voltage vs Temperature Start-up Threshold Voltage vs Temperature 11 17 10.9 10.8 10.7 VDD(MIN) (V) VTH(ON) (V) 16.8 16.6 16.4 10.6 10.5 10.4 10.3 10.2 16.2 10.1 10 16 -40 -25 -10 5 20 35 50 65 80 95 110 -40 125 -25 -10 5 20 35 50 65 80 95 110 125 Temperature (℃) Temperature (℃) PWM Frequency vs Temperature Start-up Current vs Temperature 65.300 10.000 65.200 FOSC (kHz) IDD ST (uA) 8.000 6.000 4.000 2.000 65.100 65.000 64.900 64.800 64.700 64.600 0.000 -40 -25 -10 5 20 35 50 65 80 95 110 -40 125 -25 -10 5 20 35 50 65 80 95 110 125 Temperature (℃) Temperature (℃) Green-mode min. Frequency vs Temperature PWM Frequency vs. FB 80 15.0 60 FOSC (kHz) FOSC-GREEN (kHz) 70 14.8 14.6 14.4 50 40 30 20 14.2 10 14.0 -40 -25 -10 5 20 35 50 65 80 95 110 0 125 0.6 Temperature (℃) © System General Corp. Version 1.3(IAO33.0002.B4) 0.7 0.8 0.9 1 1.1 1.2 FB(mA) -6- www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters 10uF/50V, the power-on delay TD_ON is less than 2.8S for 90VAC input. OPERATION DESCRIPTION The SG6848x1 devices integrate many useful functions into one controller for low-power switching mode power supplies. The following descriptions highlight some of the features of the SG6848D1. Start-up Circuitry When the power is turned on, the input rectified voltage, Vdc, charges the hold-up capacitor C1 via a start-up resistor RIN. As the voltage of VDD pin reaches the start threshold voltage VTH(ON), the SG6848x1 activates the entire power supply. VTH(ON) Vdc The FB input This pin is designed for feedback control and to activate the green-mode function. Figure 2 is a typical feedback circuit mainly consisting of a shunt regulator and an opto-coupler. R1 and R2 form a voltage divider for the output voltage regulation. R3 and C1 are adjusted for control-loop compensation. A small-value RC filter (e.g. RFB= 47ohm, CFB= 1nF) placed from the FB pin to GND can increase stability. The maximum source current on the FB pin is 2mA. The phototransistor must be capable of sinking this current to pull the FB level down at no load. Thus, the value of the biasing resistor Rb is determined as follows, RIN TD_ON VDD IDDST SG6848D1 Vo − VD − VZ ⋅ K ≥ 2mA Rb D1 C1 (2) GND where VD is the drop voltage of a photodiode, about 1.2V; Figure 1. Power Circuit The maximum power-on delay time is determined as follows, VTH ( ON ) = (Vdc − I DDST VZ is the minimum operating voltage of the shunt regulator. Typical value is 2.5V; K is the current transfer rate (CTR) of the opto-coupler. For an output voltage Vo=5V, with CTR=100%, the maximum value of Rb is 650ohm. TD _ ON   − ⋅ RIN ) 1 − e RIN ⋅C1  (1)   FB RFB VO Rb CFB R3 where R1 C1 IDDST is the start-up current of SG6848x1; R2 TD_ON is the power-on delay time of the power supply. Figure 2. Feedback circuit. Due to the low start-up current, a large RIN such as 1.5Mohm can be used. Also with a hold-up capacitor of © System General Corp. Version 1.3(IAO33.0002.B4) -7- www.sg.com.tw Jan. 27, 2006 Product Specification Low-cost Green-Mode PWM Controller for Flyback Converters SG6848x1 Oscillator & Green Mode Operation Built-in Slope Compensation One external resistor, RIi, connected between RI and GND pins is used to program the PWM frequency of the SG6848x1. The approximated formula is: A flyback converter can be operated in either discontinuous current mode (DCM) or continuous current mode (CCM). There are many advantages to operating the converter in CCM. With the same output power, a converter in CCM exhibits smaller peak inductor currents than one in DCM. Therefore, a small-sized transformer and a low-rated MOSFET can be applied. On the secondary side of the transformer, the rms output current of DCM can be up to twice that of CCM. Larger wire gauge and output capacitors with larger ripple current ratings are required. DCM operation also results in higher output voltage spikes. A large LC filter must also be added. Therefore, a flyback converter in CCM achieves better performance with lower component cost. FOSC ( KHz ) = 6650 RI ( Kohm ) (3) The recommended FOSC is from 50 to 100KHz. RI CI SG 6848D 1 RI GND Figure 3. Setting PWM frequency The patented green-mode function provides off-time modulation to reduce the PWM frequency at light-load and no-load conditions. The sink current of the FB pin determines the green mode operation as shown in Figure 4. At light load, the sink current of the FB pin will increase. When the sink current is larger than 1mA, the PWM frequency decreases in order to reduce the power consumption of the power supply at light-load and in no-load conditions. For lightning surge tests, a small capacitor (not over 50pF) connected from the RI pin to GND is recommended. This added capacitor also improves stability, especially at light load and high input line voltage conditions. Despite the above advantages of operating in CCM, there is one concern–stability. Operating in CCM, the output power is proportional to the average inductor current, while the peak current is controlled. This causes the well-known sub-harmonic oscillation when the PWM duty cycle exceeds 50%. Adding slope compensation (reducing the current-loop gain) is an effective way to prevent this oscillation. The SG6848x1 introduces a synchronized positive-going ramp (VSLOPE) in every switching cycle to stabilize the current loop. The sensed voltage together with this slope compensation signal (VSLOPE) is fed into the non-inverting input of the PWM comparator. The resulting voltage is compared with the FB signal to adjust the PWM duty cycle, such that the output voltage is regulated. Therefore, users can use the SG6848x1 to design a cost-effective, highly efficient and compact sized flyback power supply operating in CCM without adding any external components. The positive ramp added is, f (kHz) FOSC VSLOPE = VSL ⋅ D (4) where VSL = 0.33V; FOSC 5 D = Duty cycle IN IG FB Figure 4. PWM frequency vs. FB current. © System General Corp. Version 1.3(IAO33.0002.B4) -8- www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters Constant Output Power Limit The maximum output power of a flyback converter can generally be determined from the current-sense resistor RS. When the load increases, the peak inductor current increases accordingly. When the output current arrives at the protection value, the OCP comparator dominates the current control loop. OCP occurs when the current-sense voltage reaches the threshold value. The output GATE driver is turned off after a small propagation delay, td. The delay time results in unequal power-limit level under universal input. In the SG6848x1, a saw-tooth power-limiter is designed to solve the unequal power-limit problem. As shown in Figure 5, the power limiter is designed as a positive ramp signal and is fed to the inverting input of the OCP comparator. This results in a lower current limit at high-line inputs than at low-line inputs. However, with fixed propagation delay, td, the peak primary current would be the same for various line input voltages. Therefore the maximum output power can practically be limited to a constant value within a wide input voltage range without adding any external circuitry. UVLO level of the SG6848x1, the power supply will enter hiccup operation mode and hence limit the output power. However, it is possible that the VDD voltage remains higher than the UVLO level even if the output is shorted. This happens when the coupling between the aux and the primary winding is too good. Therefore, the construction of the transformer becomes a dominant factor. The recommended construction layout is to increase the insulation thickness for the aux winding and place the primary aux winding in one side of the bobbin. For low output voltage applications, using a low dropout voltage diode and a larger secondary winding also helps. One side Primary aux winding Primary main winding Increased thickness Secondary winding Primary main winding Figure 6. Transformer construction toff ton VTH,FLT Leading-Edge Blanking VTH,VALLEY High line sense voltage Low line sense voltage 0 T1 T2 Figure 5. Constant power limit compensation A voltage signal proportional to the MOSFET current develops on the current-sensing resistor, RS. Each time the MOSFET is turned on, a spike, which is induced by the diode reverse recovery and by the output capacitances of the MOSFET and diode, inevitably appears on the sensed signal. Inside the SG6848x1, a leading-edge blanking time of about 200 nsec. is introduced to avoid premature termination of the MOSFET by the spike. Therefore, only a small-value RC filter (e.g. 100ohm + 470pF) is required between the SENSE pin and RS. Still, a non-inductive resistor for the RS is recommended. Short Circuit Protection When the output of a flyback power supply is shorted, the primary VDD will decrease due to the coupling polarity between the aux winding and the secondary winding of a transformer. When VDD drops below the © System General Corp. Version 1.3(IAO33.0002.B4) -9- www.sg.com.tw Jan. 27, 2006 Product Specification Low-cost Green-Mode PWM Controller for Flyback Converters SG6848x1 Lab Note Before reworking or soldering/de-soldering on the power supply, it is suggested to discharge the primary capacitors by an external bleeding resistor. Otherwise the PWM IC may be destroyed by external high voltage during soldering or de-soldering. SG6848D1 Gate Blanking Circuit Sense This device is sensitive to ESD discharge. To improve the production yield, the production line should be ESD protected in accordance to ANSI ESD S1.1, ESD S1.4, ESD S7.1, ESD STM 12.1, and EOS/ESD S6.1. Printed Circuit Board (PCB) Layout Figure 7. Turn on spike Gate Drive The SG6848x1’s output stage is a fast totem pole driver that can drive a MOSFET gate directly. It is also equipped with a voltage clamping Zener diode to protect the MOSFET from damage caused by undesirable over-drive voltage. The output voltage is clamped at 15V. An internal pull-down resistor is used to avoid a floating state of the gate before startup. A gate drive resistor in the range of 47 to 100ohm is recommended. This resistor limits the peak gate drive current and provides damping to prevent oscillations at the MOSFET gate terminal. VDD In order to get better EMI performance and reduce line frequency ripples, the output of the bridge rectifier should be connected to capacitor C1 first, and then to the switching circuits. The high frequency current loop is in C1 – Transformer – MOSFET – RS – C1. The area enclosed by this current loop should be as small as possible. Keep the traces (especially 4→1) short, direct, and wide. High voltage traces related to the drain of the MOSFET and the RCD snubber should be kept far way from control circuits to prevent unnecessary interference. If a heatsink is used for the MOSFET, it’s better to connect this heatsink to a ground. As indicated by 3, the ground of control circuits should be connected first before any other circuitry. ON/OFF Driver High frequency switching current/voltage makes PCB layout a very important design issue. Good PCB layout minimizes excessive EMI and helps the power supply survive during surge/ESD tests. Here, we give some common guidelines: 15V Gate As indicated by 2, the area enclosed by the transformer aux winding, D1, and C2 should also be kept small. Place C2 close to the SG6848x1 for good decoupling. SG6848D1 Figure 8. Gate drive © System General Corp. Version 1.3(IAO33.0002.B4) Two suggestions for ground connections, with different pro and cons, are offered. - 10 - www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters GND3 → 2 → 4 → 1: This should avoid common impedance interference for the sense signal. high frequency impedance and help increase ESD immunity. GND3→2→1→4: This should be better for ESD tests, where the earth ground is not available on the power supply. Regarding the ESD discharge path, the charges go from secondary through the transformer’s stray capacitance to GND2 first. Then the charge goes from GND2 to GND1 and back to the mains. It should be noted that control circuits should not be placed in the discharge path. Point discharges for common choke can decrease the Should a Y-cap between primary and secondary be required, it is suggested to connect this Y-cap to the positive terminal of C1 (Vdc). If this Y-cap is connected to the primary GND, it should be connected to the negative terminal of C1 (GND1) directly. The Point discharge of this Y-cap also helps with ESD. However, the distance between these two points should be at least 5mm according to safety requirements. RIN Vdc D1 C1 Common mode choke C2 1 VDD 2 RI CI RFB RI Rg Gate SG6848D1 Rf Sense FB CFB Cf RS GND 4 3 Y-cap 5 Figure 9. Layout considerations © System General Corp. Version 1.3(IAO33.0002.B4) - 11 - www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters REFERENCE CIRCUIT Circuit 5V/1A F1 L1 1 CX1 2 BD1 2 - + 4 + C1 R1 C2 C3 R3 R5 R4 D4 T1 3 N R2 C6 3 1 L2 1 VO 2 D1 R10 8 5 GATE FB VDD RI SENSE + D5 + C9 Q1 1 2 GND 6 R7 C7 C8 5 3 2 2 9 22 U1 1 1,2 1 10 1 1 L 7 4 GND 3,4 R6 R9 R8 + D2 1 2 R11 C4 U2 1 3 2 R13 R14 C10 3 4 U3 CY1 1 2 R12 BOM Reference Component Reference Component BD1 BD 1A/500V L2 10uH 6mm CX1 (Optional) XC 0.1uF Q1 MOSFET 1A/600V CY1 (Optional) YC 102P/400V (Y1) R1, R2 R 750KΩ 1206 C2 EC 10uF/400V 105℃ R4, R3 R 47KΩ 1206 C1 CC 103P/500V R5 R 47Ω 1206 C3 CC 102P/500V R6 R 4.7Ω 1206 C4 EC 10u/50V R7 R 100Ω 0805 C6 CC 472P 0805 R8 R10 R 10Ω 1206 C7 (Optional) CC 102P/100V 1206 (Optional) R 10Ω 1206 C8 EC 470u/10V 105℃ C9 EC 220u/10V 105℃ R11 R 100Ω 1/8W C10 CC 222P 0805 R12 R 33KΩ 0805 R9 R 100KΩ 0805 D1 Diode FRI07 R13 R 33KΩ 1/8W D2 Diode FR102 R14 R 4.7KΩ 0805 D4 D5 Diode SB360 (Optional) ZD 6.8V 0.5W T1 EE-16 U1 IC SG6848D1 F1 R 1Ω/0.5W U2 PC817 L1 20mH 6*8mm U3 TL431 © System General Corp. Version 1.3(IAO33.0002.B4) - 12 - www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters PACKAGE INFORMATION 8 PINS - DIP (D) D Θ° 5 E1 8 B A A2 4 A1 1 e E L b1 e b Dimensions Symbol Millimeters Min. Typ. A 0.381 A2 3.175 b E 3.302 3.429 0.125 9.271 6.223 6.350 0.130 0.135 0.060 0.018 10.160 0.355 7.620 e L 0.210 0.457 9.017 Max. 0.015 1.524 b1 E1 Typ. 5.334 A1 D Inches Min. Max. 0.365 0.400 0.300 6.477 0.245 2.540 0.250 0.255 0.100 2.921 3.302 3.810 0.115 0.130 0.150 eB 8.509 9.017 9.525 0.335 0.355 0.375 θ˚ 0˚ 7˚ 15˚ 0˚ 7˚ 15˚ © System General Corp. Version 1.3(IAO33.0002.B4) - 13 - www.sg.com.tw Jan. 27, 2006 Product Specification SG6848x1 Low-cost Green-Mode PWM Controller for Flyback Converters 6PINS - SOT (T) D Detail A b 4 E E1 6 1 e c 3 1 R R θ A A2 1 L2 e1 L A1 θ L1 1 θ Detail A Dimensions Symbol Millimeters Min. Typ. Inches Min. Max. Typ. Max. A 1.45 0.057 A1 0.15 0.006 A2 0.90 b 0.30 c 0.08 D 1.15 1.30 0.036 0.50 0.011 0.22 0.003 2.90 0.045 0.009 0.114 E 2.80 0.110 E1 1.60 0.063 e 0.95 0.037 e1 1.90 0.075 L 0.30 L1 0.60 0.020 0.60 L2 R 0.45 0.051 0.020 0.018 0.024 0.024 0.25 0.010 0.10 0.004 R1 0.10 0.25 0.004 θ° 0° 4° 8° 0° 4° 8° θ1° 5° 10° 15° 5° 10° 15° © System General Corp. Version 1.3(IAO33.0002.B4) - 14 - 0.010 www.sg.com.tw Jan. 27, 2006 Product Specification Low-cost Green-Mode PWM Controller for Flyback Converters SG6848x1 DISCLAIMERS LIFE SUPPORT System General’s products are not designed to be used as components in devices intended to support or sustain human life. Use of System General’s products in components intended for surgical implant into the body, or other applications in which failure of System General’s products could create a situation where personal death or injury may occur, is not authorized without the express written approval of System General’s Chief Executive Officer. System General will not be held liable for any damages or claims resulting from the use of its products in medical applications. MILITARY System General's products are not designed for use in military applications. Use of System General’s products in military applications is not authorized without the express written approval of System General’s Chief Executive Officer. System General will not be held liable for any damages or claims resulting from the use of its products in military applications. RIGHT TO MAKE CHANGES System General reserves the right to change this document and/or this product without notice. Customers are advised to consult their System General sales representative before ordering. © System General Corp. Version 1.3(IAO33.0002.B4) - 15 - www.sg.com.tw Jan. 27, 2006 www.s-manuals.com