RT9703PS

RT9703 80mΩ, 3A Smart Universal Power Switch with Flag General Description The RT9703 is a low voltage, high performance single N-MOSFET power switch, designed for power rail on/off control with low RDS(ON) ≈ 80mΩ and full protection functions. The RT9703 equipped with a charge pump circuitry to drive the internal MOSFET switch and a flag output is available to indicate fault conditions against large di/dt which may cause the supply to fall out of regulation. In order to fit different application, an IP pin is offered for current limit point setting, a resistor from IP to ground sets the current limit for the switch. Additional features include soft-start to limit inrush current during plug-in, thermal shutdown to prevent catastrophic switch failure from high-current loads, under-voltage lockout (UVLO) to ensure that the device remains off unless there is a valid input voltage present, a precision resistor-programmable output current limit up to 3.5A. Besides, the lower quiescent current as 30μA making this device ideal for portable battery-operated equipment. The RT9703 is available in SOP-8 package requiring minimum board space and smallest components. Features Adjustable Current Limiting up to 3.5A Built-In (Typically 80mΩ) N-MOSFET Reverse Current Flow Blocking (no body diode) i.e. Output Can Be Forced Higher than Input (Off-State) Low Supply Current : 30μA Typical at Switch on State Less than 1μA Typical at Switch Off State Guaranteed 3A Continuous Load Current Wide Input Voltage Ranges : 2V to 5.5V Open-Drain Fault Flag Output Hot Plug-In Application (Soft-Start) 1.7V Typical Under-Voltage Lockout (UVLO) Thermal Shutdown Protection Smallest SOP-8 Package Minimizes Board Space RoHS Compliant and 100% Lead (Pb)-Free Applications LCD Monitor, LCD-TV USB Power Module for ADSL Information Appliance and Set-Top Box Battery-Powered Equipment Hot-Plug Power Supplies ACPI Power Distribution PCI Bus Power Switching Motherboard & Notebook PCs PC Card Hot Swap Application Ordering Information RT9703 Package Type S : SOP-8 Operating Temperature Range P : Pb Free with Commercial Standard G : Green (Halogen Free with Commercial Standard) Pin Configurations (TOP VIEW) FLG VOUT VOUT GND 2 3 4 8 7 6 5 IP VIN VIN EN Note : RichTek Pb-free and Green products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. 100%matte tin (Sn) plating. SOP-8 DS9703-08 March 2007 www.richtek.com 1 RT9703 Typical Application Circuit Pull-Up Resistor (10K to 100K) Supply Voltage 10uF Chip Enable EN VIN FLG IP RT9703 VOUT GND 33uF + Fault Flag RSET Peripheral Functional Pin Description Pin Name VIN VOUT GND EN FLG IP Pin Function Power Input Voltage Output Voltage Ground Chip Enable (Active High) Open-Drain Fault Flag Output Current Limit Programming Input Function Block Diagram VIN + - EN Bias UVLO + Gate Control Output Voltage Detection VREF IP Oscillator Charge Pump Thermal Protection VOUT FLG Delay www.richtek.com 2 DS9703-08 March 2007 RT9703 Test Circuits 1 RFG ISUPPLY VIN 2 ISUPPLY VIN FLG VFLG VOUT A CIN S1 IOUT RT9703 VOUT VIN CIN A VIN FLG ILEAKAGE + + RT9703 VOUT A RL RSET Chip Enable EN GND A COUT RSET Chip Enable RL IL EN + IP GND IP 3 VRDS(ON) 4 RFG V IOUT VIN VOUT + VIN VIN CIN RT9703 FLG EN GND IP COUT VIN CIN FLG VOUT COUT VFLG + VOUT IL Note: Above test circuits reflected the graphs shown on “ Typical Operating Characteristics” are as follows: 1–Turn-On Rising & Turn-Off Falling Time vs. Temperature, Turn-On & Off Response, Flag Response at Chip Enable, Flag Response (Enable into Current Limit) 2–On-State & Off-State Supply Current vs. Input Voltage/Temperature, Turn-Off Leakage Current vs. Temperature 3–On-Resistance vs. Input Voltage/Temperature 4–EN Threshold Voltage vs. Input Voltage/Temperature, Flag Delay Time vs. Input Voltage/Temperature, UVLO Threshold vs. Temperature, UVLO at Rising & Falling 5–Current Limit vs. Input Voltage/Temperature/RSET, Current Limit Factor vs. RSET, Short Circuit Current vs. Input Voltage, Inrush Current Response, Soft-Start Response, Current-Limit & Short Circuit with Thermal Shutdown, Short-Circuit Response DS9703-08 March 2007 www.richtek.com 3 + RSET + RT9703 EN VCE GND IP RL RSET 5 S2 CIN VIN FLG RT9703 VOUT EN GND IP RSET COUT + + IOUT VIN VOUT A S3 RL IL RT9703 Absolute Maximum Ratings (Note 1) Supply Voltage --------------------------------------------------------------------------------------------------------- 6.5V Chip Enable Input Voltage ------------------------------------------------------------------------------------------- −0.3V to 6.5V Flag Voltage ------------------------------------------------------------------------------------------------------------ 6.5V Power Dissipation, PD @ TA = 25°C SOP-8 -------------------------------------------------------------------------------------------------------------------- 0.95W Package Thermal Resistance SOP-8, θJA -------------------------------------------------------------------------------------------------------------- 104°C/W Junction Temperature ------------------------------------------------------------------------------------------------- 125°C Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------- 260°C Storage Temperature Range ---------------------------------------------------------------------------------------- −65°C to 150°°C ESD Susceptibility (Note 2) HBM (Human Body Mode) ------------------------------------------------------------------------------------------ 8kV MM (Machine Mode) -------------------------------------------------------------------------------------------------- 800V Recommended Operating Conditions (Note 3) Supply Input Voltage -------------------------------------------------------------------------------------------------- 2V to 5.5V Chip Enable Input Voltage ------------------------------------------------------------------------------------------- 0V to 5.5V Junction Temperature Range ---------------------------------------------------------------------------------------- −20°C to 100°C Electrical Characteristics (VIN = 5V, CIN = COUT = 1μF, TA = 25°C, unless otherwise specified) Parameter Switch On Resistance Supply Current Symbol RDS(ON) ISW_ON ISW_OFF Test Conditions IOUT = 3A (Note 8) Switch On, VOUT = Open Switch Off, VOUT = Open Switch Off Switch On VCE = 0V to 5.5V VCE = 0V, RLOAD = 0Ω 10% to 90% of VOUT rising ILIM x RSET VIN = 3.3V to 5.5V, RSET = 60kΩ ILIMSET = 0.5A to 3A (RSET = 420kΩ to 70kΩ) ISINK = 1mA Min ----2.0 -----−20 --2 1.3 -- Typ 80 30 0.1 --0 0.5 1.5 210k --15 0.01 4.6 1.7 0.1 Max 100 50 1 0.8 --10 --3.5 +20 400 1 8 --- Units mΩ μA V V μA μA ms AΩ A % Ω μA ms V V CE Threshold Logic-Low Voltage VIL (Note 7) Logic-High Voltage VIH CE Input Current Output Leakage Current Output Turn-On Rise Time Current Limit Factor (Note 5) Max. Current Limit Setting (Note 6) ILIMSET Current Limit Setting Accuracy FLAG Output Resistance FLAG Off Current FLAG Delay Time (Note 4) Under-Voltage Lockout Under-Voltage Hysteresis ΔILIMSET RFLG ICE ILEAKAGE TON_RISE IFLG_OFF VFLG = 5V tD VUVLO ΔVUVLO Form fault condition to FLG assertion VIN increasing VIN decreasing www.richtek.com 4 DS9703-08 March 2007 RT9703 Parameter Thermal Shutdown Protection Thermal Shutdown Hysteresis Symbol TSD ΔTSD Test Conditions Min --Typ 130 10 Max --Units °C °C Note 1. Stresses listed as the above "Absolute Maximum Ratings" may cause permanent damage to the device. These are for stress ratings. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may remain possibility to affect device reliability. Note 2. Devices are ESD sensitive. Handling precaution recommended. Note 3. The device is not guaranteed to function outside its operating conditions. Note 4. The FLAG delay time is input voltage dependent, see “ Typical Operating Characteristics” graph for further details. Note 5. Current limit is determined by: ILIMIT = 210k/RSET, where RSET is in ohms. Note 6. It is important to note that the maximum current limit value shall be set properly in accordance with its supply voltage otherwise which it may result in the failure occurrence. See “ Maximum Current Limit vs. Supply Voltage” graph shown on the applications information section for further details. Note 7. For input voltage lower than 5V, the threshold level will subject to ±0.6V deviation throughout the operating junction temperature range. Refer to the “ Typical Operating Characteristics” graph for further details. Note 8. RDS(ON) is measured at constant junction temperature by using a 1ms current pulse. DS9703-08 March 2007 www.richtek.com 5 RT9703 Typical Operating Characteristics 2 On-State Supply Current vs. Input Voltage 50 45 2 Off-State Supply Current vs. Input Voltage 2 1.5 VEN = 5V CIN = 10uF RL = Open RSET = 100kΩ VEN = 5V CIN = 10uF COUT = 33uF RL = Open RSET = 100kΩ Supply Current (uA) A Supply Current (uA) A 40 35 30 25 20 15 10 1 0.5 0 -0.5 -1 -1.5 -2 1.5 2 2.5 3 3.5 4 4.5 5 5.5 1.5 2 2.5 3 3.5 4 4.5 5 5.5 Input Voltage (V) Input Voltage (V) 2 On-State Supply Current vs. Temperature 50 45 2 Off-State Supply Current vs. Temperature 2 1.5 VIN = VEN = 5V CIN = 10uF VIN = 5V, VEN = 0V CIN = 10uF COUT = 33uF RL = Open RSET = 100kΩ Supply Current (uA) A 20 40 60 80 100 120 Supply Current (uA) A 40 35 30 25 20 15 10 COUT = 33uF RL = Open RSET = 100kΩ 1 0.5 0 -0.5 -1 -1.5 -2 -40 -20 0 Temperature (° C) -40 -20 0 20 40 60 80 100 120 Temperature (° C) 5 2.1 Current Limit vs. Input Voltage CIN = 10uF, COUT = 33uF RL = 0.5Ω, RSET = 116kΩ 2 5 2.1 Current Limit vs. Temperature VIN = 5V CIN = 10uF, COUT = 33uF RL = 0.5Ω , RSET = 116kΩ S2 = ON, S3 = OFF S2 = ON, S3 = OFF 2 Current Limit (A) Current Limit (A) 1.9 1.9 1.8 1.8 1.7 1.7 1.6 2 2.5 3 3.5 4 4.5 5 5.5 1.6 -40 -20 0 20 40 60 80 100 120 Input Voltage (V) www.richtek.com 6 Temperature (° C) DS9703-08 March 2007 RT9703 5 3 Current Limit vs. RSET 4 3.5 3 On-Resistance vs. Input Voltage 70 69 VIN = 5V, RL = 0.5Ω CIN = 10uF, COUT = 33uF IOUT = 0.5A, RSET = 50kΩ CIN = 10uF, COUT = 33uF On-Resistance (mΩ) 500 S2 = ON, S3 = OFF 68 67 66 65 64 63 62 Current Limit (A) 2.5 2 1.5 1 0.5 0 50 100 150 200 250 300 350 400 450 2 2.5 3 3.5 4 4.5 5 5.5 RSET (k Ω) 3 88 Input Voltage (V) On-Resistance vs. Temperature IOUT = 0.5A, RSET = 50kΩ CIN = 10uF, COUT = 33uF VIN = 5V 5 Short Circuit Current Response VIN = 5V, CIN = 10uF, COUT = 0.1uF RSET = 175kΩ, S2 = S3 = ON VOUT (5V/Div) On-Resistance (mΩ) 78 68 58 IOUT (0.5A/Div) 48 -40 -20 0 20 40 60 80 100 120 Time (10ms/Div) Temperature (° C) 4 2.4 5 Inrush Current Response E Threshold Voltage vs. Input Voltage CE N Pin Threshold Voltage vs. Input CIN = 10uF, COUT = 33uF IL = 100mA, RSET = 100kΩ EN Pin Threshold Voltage (V) CE EN Threshold Voltage (V) 2 1.6 1.2 0.8 0.4 0 2 COUT = 1000uF COUT = 470uF COUT = 1uF (1A/Div) VIN = 5V, CIN = 10uF RL = 0.5Ω, RSET = 175kΩ, S2 = ON, S3 = OFF Time (5ms/Div) 2.5 3 3.5 4 4.5 5 5.5 Input Voltage (V) DS9703-08 March 2007 www.richtek.com 7 RT9703 4 2.4 CE Threshold Voltage vs. Temperature EN Pin Threshold Voltage vs. VIN = 5V, IL = 100mV RSET = 100kΩ CIN = 10uF, COUT = 33uF 1 Turn-On Rising Time vs. Temperature 4 3.5 3 2.5 2 1.5 1 0.5 0 VIN = VEN = 5V CIN = 10uF, COUT = 1uF RL = 30Ω, RSET = 200kΩ S1 = ON EN Pin Threshold Voltage (V) CE Thresold Voltage (V) 1.6 1.2 0.8 0.4 0 -40 -20 0 20 40 60 80 100 120 Turn-On Rising Time (ms) 2 -40 -20 0 20 40 60 80 100 120 Temperature (° C) Temperature (° C) 1 Turn-Off Falling Time vs. Temperature 6 5 4 3 2 1 0 -40 -20 0 20 40 60 80 100 120 2 Turn-Off Leakage Current vs. Temperature 0.3 Turn-Off Leakage Current (uA) a VIN = 5V, VEN = 0V CIN = 10uF, COUT = 1uF RL = 30Ω, RSET = 200kΩ S1 = ON VIN = 5V, VEN = 0V CIN = 10uF, COUT = 33uF RL = 0Ω, RSET = 100kΩ Turn-Off Falling Time (us) 0.2 0.1 0 -0.1 -0.2 -0.3 -40 -20 0 20 40 60 80 100 120 Temperature (° C) 4 10 Temperature (° C) 4 9 Flag Dealy Time vs. Input Voltage VEN = 5V CIN = 10uF, COUT = 33uF RL = 0.5Ω, RSET = 100kΩ RFG = 1kΩ 6 Flag Delay Time vs. Temperature VIN = VEN = 5V CIN = 10uF, COUT = 33uF RL = 0.5Ω, RSET = 100kΩ RFG = 1kΩ 7 Flag Delay Time (ms) 4 Flag Delay Time (ms) 4 4.5 5 5.5 8 8 6 2 5 0 2 2.5 3 3.5 4 -40 -20 0 20 40 60 80 100 120 Input Voltage (V) Temperature (° C) www.richtek.com 8 DS9703-08 March 2007 RT9703 4 3.5 3 UVLO Threshold vs. Temperature CIN = 10uF, COUT = 33uF RL = 1kΩ, RSET = 100kΩ 1 Turn-On Response UVLO Threshold (V) 2.5 2 1.5 1 0.5 0 -40 -20 0 20 40 60 80 100 120 VEN (5V/ VOUT ( 1V/ VIN = 5V, S1 = ON CIN = 10uF, COUT = 1uF RL = 33Ω, RSET = 200kΩ Time (250us/Div) Temperature (° C) 1 Turn-Off Response VIN = 5V, S1 = OFF CIN = 10uF, COUT = 1uF RL = 30Ω, RSET = 200kΩ VEN (5V/Div) 4 UVLO at Rising VOUT (5V/Div) VIN (1V/Div) IL (100mA/Div) VOUT (1V/Div) VIN = VEN = 5V CIN = 1000uF, COUT = 1uF Time (100us/Div) Time (1ms/Div) 4 UVLO at Falling VIN = VEN = 5V CIN = 1000uF, COUT = 1uF RL = 30Ω, RSET = 200kΩ 1 FLAG Response when Enable into Current Limit VEN (5V/Div) VFLG (5V/Div) VIN = 5V CIN = 1uF, COUT = 33uF RL = 0.5Ω, RSET = 175kΩ RFG = 1kΩ, S1 = OFF VIN (1V/Div) VOUT (1V/Div) IL (1A/Div) Time (25ms/Div) Time (1ms/Div) DS9703-08 March 2007 www.richtek.com 9 RT9703 1 FLAG Response at Chip Enable 5 Current Limit with Thermal Shutdown VIN = 5V CIN = 10uF COUT = 33uF RL = 0.5Ω, RSET = 116kΩ S2 = ON, S3 = OFF VEN (5V/Div) VFLG (5V/Div) VIN = 5V CIN = 1uF, COUT = 33uF RL = 0.5Ω, RSET = 420kΩ RFG = 1kΩ, S1 = OFF VEN (5V/Div) IL (0.5A/Div) IL (1A/Div) Time (10ms/Div) Time (50ms/Div) 5 Short- Circuit with Thermal Shutdown VIN = 5V, CIN = 10uF, COUT = 33uF RSET = 140kΩ, S2 = ON, S3 = ON VTRIGGER (5V/Div) 5 Soft-Start Response with Current Limit VIN (5V/Div) VEN (5V/Div) VOUT (5V/Div) IL (0.5A/Div) IL (2A/Div) CIN = 10uF, COUT = 1uF RL = 0.5Ω, RSET = 70kΩ Time (10ms/Div) Time (1ms/Div) www.richtek.com 10 DS9703-08 March 2007 RT9703 Applications Information The RT9703 is a high-side, N-Channel, power switch ≈ available with active-high enable input. Low RDS(ON)dd 80mΩ and full protection functions make it optimized to replace complex discrete on/off control circuitry. Input and Output VIN (input) is the power source connection to the internal circuitry and the drain of the MOSFET. VOUT (output) is the source of the MOSFET. In a typical application, current flows through the switch from VIN to VOUT toward the load. If VOUT is greater than VIN, current will flow from VOUT to VIN since the MOSFET is bidirectional when on. Unlike a normal MOSFET, there is no a parasitic body diode between drain and source of the MOSFET, the RT9703 prevents reverse current flow if VOUT being externally forced to a higher voltage than VIN when the output disabled (VEN < 0.8V). Fault Flag The RT9703 provides a FLG signal pin which is an N-Channel open drain MOSFET output. This open drain output goes low when VOUT < VIN −1V, current limit or the die temperature exceeds 130°C approximately. The FLG output is capable of sinking a 10mA load to typically 150mV above ground. The FLG pin requires a pull-up resistor, this resistor should be large in value to reduce energy drain. A 100kΩ pull-up resistor works well for most applications. In the case of an over-current condition, FLG will be asserted only after the flag response delay time, tD, has elapsed. This ensures that FLG is asserted only upon valid over-current conditions and that erroneous error reporting is eliminated. For example, false over-current conditions may occur during hot-plug events when a highly large capacitive load is connected and causes a high transient inrush current that exceeds the current limit threshold. The FLG response delay time tD is typically 4.6ms. Under-voltage Lockout Under-voltage lockout (UVLO) prevents the MOSFET switch from turning on until input voltage exceeds approximately 1.7V. If input voltage drops below approximately 1.3V, UVLO turns off the MOSFET switch, FLG will be asserted accordingly. Under- voltage detection functions only when the chip enable input is enabled. Current Limiting and Short-Circuit Protection The current limit circuitry prevents damage to the MOSFET switch and external load. It is user adjust- able with an external set resistor, RSET, ILIMIT = 210kΩ/RSET in the range of 0.5A to 3A. The accuracy of current limit set point may vary with operating temperature and supply voltage. See “Typical Operating Characteristics” graph for further details. D S D S G G Normal MOSFET Chip Enable Input RT9703 The switch will be disabled when the EN pin is in a logic low condition. During this condition, the internal circuitry and MOSFET are turned off, reducing the supply current to 0.1μA typically. The maximum guaranteed voltage for a logic low at the EN pin is 0.8V. A minimum guaranteed voltage of 2V at the EN pin will turn the RT9703 back on. Floating the input may cause unpredictable operation. EN should not be allowed to go negative with respect to GND. The EN pin may be directly tied to VIN to keep the part on. Soft-Start for Hot Plug-In Applications In order to eliminate the upstream voltage droop caused by the large inrush current during hot-plug events, the “soft-start” feature effectively isolates the power source from extremely large capacitive loads. DS9703-08 March 2007 www.richtek.com 11 RT9703 The normal current limit value, ILIMIT, is set with an external resistor between IP (pin 8) and GND (pin 4). When a heavy load or short circuit is applied to an enabled switch, a large transient current may flow until the current limit circuitry responds. Once this current limit threshold is exceeded, the device enters constant current mode until the thermal shutdown occurred or the fault is removed. It is important to note that the maximum current limit value shall be set properly in accordance with its supply voltage otherwise it may result in the failure occurrence. The graph below shows the maximum current limit and supply voltage on the safe operation area. the junction temperature does not exceed 100°C. With all possible conditions, the junction temperature must be within the range specified under operating conditions. Power dissipation can be calculated based on the output current and the RDS(ON) of switch as below. PD = RDS(ON) x IOUT2 Although the devices are rated for 3A of output current, but the application may limit the amount of output current based on the total power dissipation and the ambient temperature. The final operating junction temperature for any set of conditions can be estimated by the following thermal equation : PD(MAX) = ( TJ(MAX) - TA ) / θJA Where TJ(MAX) is the maximum junction temperature of the die (100°C) and TA is the maximum ambient temperature. The junction to ambient thermal resistance (θJA) for SOP8 package at recommended minimum footprint is 104°C/ W (θJA is layout dependent). Supply Filter/Bypass Capacitor A 10μF low-ESR ceramic capacitor from VIN to GND (the amount of the capacitance may be increased without limit), located at the device is strongly recommended to prevent the input voltage drooping during hot-plug events. However, higher capacitor values will further reduce the voltage droop on the input. Furthermore, without the bypass capacitor, an output short may cause sufficient ringing on the input (from source lead inductance) to destroy the internal control circuitry. An important note to be award of is the parasitic inductance of PCB traces can cause over-voltage transients if the PCB trace has even a few tens of nH of inductance. It is recommended to use aluminum electrolytic acted the supply capacitor to prevent the device from being damaged. The input transient MUST not exceed 6.5V of the absolute maximum supply voltage even for a short duration. Maximun Current Limit vs. Supply Voltage 5 4.5 4 3.5 3 2.5 2 1.5 1 0.5 0 2 2.5 3 3.5 4 4.5 5 5.5 TA = 25°C Maximun Current Limit (A) A Supply Voltage (V) Thermal Shutdown Thermal shutdown is employed to protect the device from damage if the die temperature exceeds approximately 130°C. If enabled, the switch automatically restarts when the die temperature falls 10°C. The output and FLG signal will continue to cycle on and off until the device is disabled or the fault is removed. Power Dissipation The device's junction temperature depends on several factors such as the load, PCB layout, ambient temperature and package type. The output pin of RT9703 can deliver a current of up to 3A over the full operating junction temperature range. However, the maximum output current must be derated at higher ambient temperature to ensure www.richtek.com 12 DS9703-08 March 2007 RT9703 Fault Flag Filtering (Optional) The transient inrush current to downstream capacitance may cause a short-duration error flag, which may cause erroneous over-current reporting. A simple 1ms RC lowpass filter (10kΩ and 0.1μF) in the flag line eliminates short-duration transients. IP GND VIN EN PCB Layout In order to meet the voltage drop, droop, and EMI requirements, careful PCB layout is necessary. The following guidelines must be considered: Keep all input and output traces as short as possible and use at least 150-mil & 2 ounce copper for all races. Avoid vias as much as possible. If vias are necessary, make them as large as feasible. Place a ground plane under all circuitry to lower both resistance and inductance and improve DC and transient performance (Use a separate ground and power plans if possible). Locate the bypass capacitors as close as possible to the input and output pin of the RT9703. Board Layout GND FLG VOUT GND DS9703-08 March 2007 www.richtek.com 13 RT9703 Outline Dimension A H M J B F C I D Dimensions In Millimeters Symbol Min A B C D F H I J M 4.801 3.810 1.346 0.330 1.194 0.170 0.050 5.791 0.400 Max 5.004 3.988 1.753 0.508 1.346 0.254 0.254 6.200 1.270 Dimensions In Inches Min 0.189 0.150 0.053 0.013 0.047 0.007 0.002 0.228 0.016 Max 0.197 0.157 0.069 0.020 0.053 0.010 0.010 0.244 0.050 8-Lead SOP Plastic Package Richtek Technology Corporation Headquarter 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Richtek Technology Corporation Taipei Office (Marketing) 8F, No. 137, Lane 235, Paochiao Road, Hsintien City Taipei County, Taiwan, R.O.C. Tel: (8862)89191466 Fax: (8862)89191465 Email: marketing@richtek.com www.richtek.com 14 DS9703-08 March 2007