RT8016L 1.5MHz, 600mA, High Efficiency PWM Step-Down DC/DC Converter General Description Features The RT8016L is a high-efficiency Pulse-Width-Modulated (PWM) step-down DC/DC converter capable of delivering up to 600mA output current over a wide input voltage range from 2.5V to 5.5V. The RT8016L is ideally suited for portable electronic devices that are powered from 1-cell Li-ion battery or from other power sources, such as cellular phones, PDAs and hand-held devices. z Two operating modes are available including : PWM/low dropout autoswitch mode and shut-down mode. The internal synchronous rectifier with low RDS(ON) dramatically reduces conduction loss at PWM mode. No external Schottky diode is required in practical application. The RT8016L enters low dropout mode when normal PWM can not provide regulated output voltage by continuously turning on the upper P-MOSFET. The RT8016L enters Shut-down mode and consumes less than 0.1μA when the EN pin is pulled low. The RT8016L also offers a fixed output voltage with a range from 1V to 3.3V with 0.1V per step or an adjustable output voltage via two external resistors. The switching ripple is easily smoothed out by small package filtering elements due to a fixed operating frequency of 1.5MHz. Other features include soft-start, lower internal reference voltage with 2% accuracy, over temperature protection, and over current protection. The IC is available in a WQFN-8L 1.6x1.6 (COL) package which allows small PCB area application. NC 8 1 7 2 6 5 4 FB/VOUT GND LX NC WQFN-8L 1.6x1.6 (COL) DS8016L-02 March 2011 z z z z Applications z z z z z Mobile Phones Personal Information Appliances Wireless and DSL Modems MP3 Players Portable Instruments Ordering Information RT8016LPackage Type QW : WQFN-8L 1.6x1.6 (COL) (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) Output Voltage Default : Adjustable 10 : 1.0V 11 : 1.1V : 32 : 3.2V 33 : 3.3V Note : Richtek products are : RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020. (TOP VIEW) 3 z ` Pin Configurations GND EN VIN z Input Range : 2.5V to 5.5V Adjustable Output Voltage Range : 0.6V to VIN 600mA Output Current Efficiency up to 95% No Schottky Diode Required 1.5MHz Fixed-Frequency PWM Operation RoHS Compliant and Haloger Free ` Suitable for use in SnPb or Pb-free soldering processes. Marking Information BSW BS : Product Code W : Date Code www.richtek.com 1 RT8016L Typical Application Circuit VIN 2.5V to 5.5V 3 CIN 4.7µF VIN LX 5 L 2.2µH VOUT RT8016L 2 EN VOUT 3 VIN 2.5V to 5.5V COUT 2 10µF GND 1, 6 LX 5 VOUT C1 RT8016L 4.7µF 7 VIN CIN L 2.2µH EN R1 FB COUT 7 10µF GND 1, 6 IR2 R2 VOUT = VREF x ⎛⎜ 1 + R1 ⎞⎟ ⎝ R2 ⎠ with R2 = 300kΩ to 60kΩ so IR2 = 2μA to 10μA, Figure 1. Fixed Voltage Regulator and (R1 x C1) should be in the range between 3x10-6 and 6x10-6 for component selection. Figure 2. Adjustable Voltage Regulator Functional Pin Description Pin No. 1, 6 Pin Name Pin Function GND Ground Pin. 2 EN Chip Enable (Active High). 3 VIN Power Input Pin 4, 8 NC No Internal Connection. 5 LX Switching Pin for Step-down Converter 7 FB/VOUT Feedback/Output Voltage Pin. Function Block Diagram EN VIN RS1 OSC & Shutdown Control Current Limit Detector Slope Compensation Current Sense FB/VOUT Error Amplifier Control Logic PWM Comparator UVLO & Power Good Detector LX Mux Current Source Controller RC CCOMP Driver Current Detector VREF RS2 GND www.richtek.com 2 DS8016L-02 March 2011 RT8016L Absolute Maximum Ratings z z z z z z z z (Note 1) Supply Input Voltage, VIN ----------------------------------------------------------------------------------------------EN, FB Pin Voltage ------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C WQFN-8L 1.6x1.6 (COL) -----------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) WQFN-8L 1.6x1.6 (COL), θJA ------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Mode) ---------------------------------------------------------------------------------------------MM (Machine Mode) ------------------------------------------------------------------------------------------------------ Recommended Operating Conditions z z z 6.5V −0.3V to VIN 0.833W 120°C/W 260°C −65°C to 150°C 150°C 2kV 200V (Note 4) Supply Input Voltage, VIN ------------------------------------------------------------------------------------------------ 2.5V to 5.5V Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C Electrical Characteristics (VIN = 3.6V, VOUT = 2.5V, VREF = 0.6V, L = 2.2μH, CIN = 4.7μF, COUT = 10μF, TA = 25°C, IMAX = 600mA unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Quiescent Current IQ IOUT = 0mA, VFB = VREF + 5% -- 50 70 μA Shutdown Current ISHDN EN = GND -- 0.1 1 μA Reference Voltage VREF For Adjustable Output Voltage 0.588 0.6 0.612 V Adjustable Output Range VOUT (Note 6) V REF -- VIN − 0.2V V −3 -- 3 % −3 -- 3 % −50 -- 50 nA VIN = 3.6V -- 0.28 -- VIN = 2.5V -- 0.38 -- VIN = 3.6V -- 0.25 -- VIN = 2.5V -- 0.35 -- 0.6 1.5 -- A Output Voltage Accuracy Fixed ΔV OUT Adjustable ΔV OUT VIN = (VOUT + ΔV) to 5.5V or VIN > 2.5V whichever is larger. (Note 5) VIN = V OUT + ΔV to 5.5V (Note 5) 0A < IOUT < 600mA FB Input Current IFB VFB = VIN P-MOSFET RON RDS(ON)_P IOUT = 200mA N-MOSFET RON RDS(ON)_N IOUT = 200mA P-Channel Current Limit ILIM_P VIN = 2.5V to 5.5 V Logic High VEN_H 1.5 -- VIN V Logic Low VEN_L -- -- 0.4 V UVLO Threshold VUVLO -- 1.8 -- V UVLO Hysteresis ΔV UVLO -- 0.1 -- V Oscillator Frequency fOSC 1.2 1.5 1.8 MHz EN Input Voltage VIN = 3.6V, IOUT = 100mA Ω Ω To be continued DS8016L-02 March 2011 www.richtek.com 3 RT8016L Parameter Symbol Thermal Shutdown Temperature T SD Maximum Duty Cycle DMAX LX Current Source Test Conditions V IN = 3.6V, V LX = 0V or VLX = 3.6V Min Typ Max Unit -- 160 -- °C 100 -- -- % 1 -- 100 μA 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. θJA is measured in the natural convection at TA = 25°C on a high effective thermal conductivity four-layer test board of JEDEC 51-7 thermal measurement standard. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Note 5. ΔV = IOUT x PRDS(ON) Note 6. Guarantee by design. www.richtek.com 4 DS8016L-02 March 2011 RT8016L Typical Operating Characteristics Output Voltage vs. Input Voltage Efficiency vs. Output Current 100 1.900 90 1.875 1.850 VIN = 3.3V VIN =3.6V VIN =4.2V 70 60 Output Voltage (V) Efficiency (%) 80 50 40 30 20 1.825 1.800 1.775 1.750 1.725 1.700 1.675 1.650 10 1.625 VOUT = 1.8V 0 1.600 0 0.2 0.4 0.6 0.8 1 2.5 3.0 3.5 Output Current (A) 1.875 1.95 1.850 1.90 1.825 Output Voltage (V) Output Voltage (V) 2.00 VIN = 3.3V VIN = 3.6V VIN = 4.2V 1.775 1.750 1.725 1.700 1.675 5.0 5.5 1.85 1.80 1.75 1.70 1.65 1.60 1.650 1.55 1.625 VIN = 3.6V, VOUT = 1.8V 1.50 1.600 0 0.2 0.4 0.6 0.8 -50 1 -25 0 EN Threshold vs. Input Voltage 1.1 1.1 EN Threshold (V)1 1.2 1.0 Rising 0.8 Falling 0.7 0.6 VIN = 3.6V 0.5 2.5 3.0 3.5 4.0 4.5 Input Voltage (V) DS8016L-02 March 2011 50 75 100 125 EN Threshold vs. Temperature 1.2 0.9 25 Temperature (°C) Output Current (A) EN Threshold (V)1 4.5 Output Voltage vs. Temperature Output Voltage vs. Output Current 1.900 1.800 4.0 Input Voltage (V) 5.0 5.5 1.0 0.9 Rising 0.8 Falling 0.7 0.6 VIN = 3.6V 0.5 -50 -25 0 25 50 75 100 125 Temperature (°C) www.richtek.com 5 RT8016L Frequency vs. Temperature 1.7 1.6 1.6 Frequency(MHz)1 Frequency (MHz)1 Frequency vs. Input Voltage 1.7 1.5 1.4 1.3 1.2 1.5 1.4 1.3 1.2 1.1 1.1 IOUT = 100mA 1.0 2.5 3.0 3.5 4.0 4.5 5.0 VIN = 3.6V, IOUT = 100mA 1.0 -50 5.5 -25 0 Input Voltage threshold vs. Temperature 60 2.0 55 Quiescent Current (μA) 0 Input Voltage (V) 75 100 125 Quiescent Current vs. Temperature 2.1 Rising 1.8 1.7 50 Temperature(°C) Input Voltage (V) 1.9 25 Falling 1.6 1.5 1.4 50 45 40 35 30 25 1.3 IOUT = 0mA VIN = 3.6V 20 1.2 -50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 Temperature (°C) Temperature (°C) Current Limit vs. Input Voltage Power On from EN 100 125 1.8 VIN = 3.6V, VOUT = 1.8V, lOUT = 100mA 1.7 Output Current (A) 1.6 1.5 VEN (2V/Div) 1.4 1.3 VOUT (1V/Div) 1.2 1.1 1.0 0.9 VIN = 3.6V IOUT (500mA/Div) 0.8 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Time (500μs/Div) Input Voltage (V) www.richtek.com 6 DS8016L-02 March 2011 RT8016L Power Off from EN Power On from EN VIN = 3.6V, VOUT = 1.8V, IOUT = 100mA VEN (2V/Div) VEN (2V/Div) VOUT (1V/Div) VOUT (1V/Div) I IN (500mA/Div) VIN = 3.6V, VOUT = 1.8V, IOUT = 1A I IN (50mA/Div) Time (500μs/Div) Time (250μs/Div) Power Off from EN Output Ripple Voltage VIN = 3.6V, VOUT = 1.8V, IOUT = 1A VEN (2V/Div) VLX (5V/Div) VOUT (1V/Div) VOUT (10mV/Div) I IN (500mA/Div) VIN = 3.6V, VOUT = 1.8V, IOUT = 1A Time (50μs/Div) Time (500ns/Div) Load Transient Response Load Transient Response Output Voltage (100mV/Div) Output Voltage (100mV/Div) Output Current (500mA/Div) Output Current (500mA/Div) VIN = 3.6V, IOUT = 50mA to 500mA Time (100μs/Div) DS8016L-02 March 2011 VIN = 3.6V, IOUT = 50mA to 1000mA Time (100μs/Div) www.richtek.com 7 RT8016L Application Information The basic RT8016L application circuit is shown in Typical Application Circuit. External component selection is determined by the maximum load current and begins with the selection of the inductor value and operating frequency followed by CIN and COUT. Inductor Selection For a given input and output voltage, the inductor value and operating frequency determine the ripple current. The ripple current ΔIL increases with higher VIN and decreases with higher inductance: ⎤ ⎡V ⎤ ⎡ V ΔIL = ⎢ OUT ⎥ x ⎢1− OUT ⎥ VIN ⎦ ⎣F x L ⎦ ⎣ Having a lower ripple current reduces the ESR losses in the output capacitors and the output voltage ripple. Highest efficiency operation is achieved at low frequency with small ripple current. This, however, requires a large inductor. A reasonable starting point for selecting the ripple current is ΔIL = 0.4(IMAX). The largest ripple current occurs at the highest VIN. To guarantee that the ripple current stays below a specified maximum, the inductor value should be chosen according to the following equation : ⎡ VOUT ⎤ ⎡ ⎤ V L=⎢ ⎥ x ⎢1− OUT ⎥ ⎣⎢ f x ΔIL(MAX) ⎦⎥ ⎢⎣ VIN(MAX) ⎦⎥ Inductor Core Selection Once the value for L is known, the type of inductor can be selected. High efficiency converters generally cannot afford the core loss found in low cost powdered iron cores, forcing the use of more expensive ferrite or mollypermalloy cores. Actual core loss is independent of core size for a fixed inductor value but it is very dependent on the inductance selected. As the inductance increases, core losses decrease. Unfortunately, increased inductance requires more turns of wire and therefore copper losses will increase. Ferrite designs have very low core losses and are preferred at high switching frequencies, so design goals can concentrate on copper loss and preventing saturation. Ferrite core material saturates “hard”, which means that inductance collapses abruptly when the peak design current is exceeded. This results in an abrupt increase in inductor ripple current and consequent output voltage ripple. Do not allow the core to saturate! www.richtek.com 8 Different core materials and shapes will change the size/ current and price/current relationship of an inductor. Toroid or shielded pot cores in ferrite or permalloy materials are small and don't radiate energy but generally cost more than powdered iron core inductors with similar characteristics. The choice of which style inductor to use mainly depends on the price vs. size requirements and any radiated field/EMI requirements. CIN and COUT Selection The input capacitance, C IN, is needed to filter the trapezoidal current at the source of the top MOSFET. To prevent large ripple voltage, a low ESR input capacitor sized for the maximum RMS current should be used. RMS current is given by : IRMS = IOUT(MAX) VOUT VIN VIN −1 VOUT This formula has a maximum at VIN = 2VOUT, where IRMS = IOUT/2. This simple worst case condition is commonly used for design because even significant deviations do not offer much relief. Note that ripple current ratings from capacitor manufacturers are often based on only 2000 hours of life which makes it advisable to further derate the capacitor, or choose a capacitor rated at a higher temperature than required. Several capacitors may also be paralleled to meet size or height requirements in the design. The selection of COUT is determined by the effective series resistance (ESR) that is required to minimize voltage ripple and load step transients, as well as the amount of bulk capacitance that is necessary to ensure that the control loop is stable. Loop stability can be checked by viewing the load transient response as described in a later section. The output ripple, ΔVOUT, is determined by : ⎡ 1 ⎤ ΔVOUT ≤ ΔIL ⎢ESR + ⎥ 8fCOUT ⎦ ⎣ The output ripple is highest at maximum input voltage since ΔIL increases with input voltage. Multiple capacitors placed in parallel may be needed to meet the ESR and RMS current handling requirements. Dry tantalum, special polymer, aluminum electrolytic and ceramic capacitors are DS8016L-02 March 2011 RT8016L all available in surface mount packages. Special polymer capacitors offer very low ESR but have lower capacitance density than other types. Tantalum capacitors have the highest capacitance density but it is important to only use types that have been surge tested for use in switching power supplies. Aluminum electrolytic capacitors have significantly higher ESR but can be used in cost sensitive applications provided that consideration is given to ripple current ratings and long term reliability. Ceramic capacitors have excellent low ESR characteristics but can have a high voltage coefficient and audible piezoelectric effects. The high Q of ceramic capacitors with trace inductance can also lead to significant ringing. Using Ceramic Input and Output Capacitors Higher values, lower cost ceramic capacitors are now becoming available in smaller case sizes. Their high ripple current, high voltage rating and low ESR make them ideal for switching regulator applications. However, care must be taken when these capacitors are used at the input and output. When a ceramic capacitor is used at the input and the power is supplied by a wall adapter through long wires, a load step at the output can induce ringing at the input, VIN. At best, this ringing can couple to the output and be mistaken as loop instability. At worst, a sudden inrush of current through the long wires can potentially cause a voltage spike at VIN large enough to damage the part. Output Voltage Programming The resistive voltage divider allows the FB pin to sense a fraction of the output voltage as shown in Figure 3. VOUT R1 ) R2 where VREF is the internal reference voltage (0.6V typ.) VOUT = VREF (1 + Efficiency Considerations The efficiency of a switching regulator is equal to the output power divided by the input power times 100%. It is often useful to analyze individual losses to determine what is limiting the efficiency and which change would produce the most improvement. Efficiency can be expressed as : Efficiency = 100% − (L1+ L2+ L3+ ...) where L1, L2, etc. are the individual losses as a percentage of input power. Although all dissipative elements in the circuit produce losses, two main sources usually account for most of the losses : VIN quiescent current and I2R losses. The VIN quiescent current loss dominates the efficiency loss at very low load currents whereas the I2R loss dominates the efficiency loss at medium to high load currents. In a typical efficiency plot, the efficiency curve at very low load currents can be misleading since the actual power lost is of no consequence. 1. The VIN quiescent current appears due to two factors including : the DC bias current as given in the electrical characteristics and the internal main switch and synchronous switch gate charge currents. The gate charge current results from switching the gate capacitance of the internal power MOSFET switches. Each time the gate is switched from high to low to high again, a packet of charge ΔQ moves from VIN to ground. The resulting ΔQ/Δt is the current out of VIN that is typically larger than the DC bias current. In continuous mode, IGATECHG = f (QT+QB) R1 FB RT8016L R2 GND Figure 3. Setting the Output Voltage For adjustable voltage mode, the output voltage is set by an external resistive voltage divider according to the following equation : DS8016L-02 March 2011 where QT and QB are the gate charges of the internal top and bottom switches. Both the DC bias and gate charge losses are proportional to VIN and thus their effects will be more pronounced at higher supply voltages. 2. I2R losses are calculated from the resistances of the internal switches, R SW and external inductor R L. In continuous mode, the average output current flowing through inductor L is “chopped” between the main switch and the synchronous switch. Thus, the series resistance www.richtek.com 9 RT8016L looking into the LX pin is a function of both top and bottom MOSFET RDS(ON) and the duty cycle (DC) as follows : test board. The maximum power dissipation at TA = 25°C RSW = RDS(ON)TOP x DC + RDS(ON)BOT x (1−DC) P D(MAX) = (125°C − 25°C) / (120°C/W) = 0.833W for WQFN-8L 1.6x1.6 (COL) package Other losses including CIN and COUT ESR dissipative losses and inductor core losses generally account for less than 2% of the total loss. The maximum power dissipation depends on the operating ambient temperature for fixed T J (MAX) and thermal resistance, θJA. For the RT8016L package, the derating curve in Figure 4 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation. Maximum Power Dissipation (W)1 The RDS(ON) for both the top and bottom MOSFETs can be obtained from the Typical Operating Characteristics curves. Thus, to obtain I2R losses, simply add RSW to RL and multiply the result by the square of the average output current. can be calculated by the following formula: Checking Transient Response The regulator loop response can be checked by looking at the load transient response. Switching regulators take several cycles to respond to a step in load current. When a load step occurs, VOUT immediately shifts by an amount equal to ΔILOAD (ESR), where ESR is the effective series resistance of COUT. ΔILOAD also begins to charge or discharge COUT generating a feedback error signal used by the regulator to return VOUT to its steady state value. During this recovery time, VOUT can be monitored for overshoot or ringing which would indicate a stability problem. Thermal Considerations 0.9 Four Layer PCB 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 0 25 50 75 100 125 Ambient Temperature (°C) (°C) Figure 4 Layout Considerations For continuous operation, do not exceed absolute maximum junction temperature. The maximum power dissipation depends on the thermal resistance of the IC package, PCB layout, rate of surrounding airflow, and difference between junction and ambient temperature. The maximum power dissipation can be calculated by the following formula : Follow the PCB layout guidelines for optimal performance of the RT8016L. PD(MAX) = (TJ(MAX) − TA) / θJA where TJ(MAX) is the maximum junction temperature, TA is the ambient temperature, and θJA is the junction to ambient thermal resistance. For recommended operating condition specifications of the RT8016L, the maximum junction temperature is 125°C and TA is the ambient temperature. The junction to ambient thermal resistance, θJA, is layout dependent. For WQFN8L 1.6x1.6 (COL) packages, the thermal resistance, θJA, is 120°C/W on a standard JEDEC 51-7 four-layer thermal www.richtek.com 10 ` For the main current paths, keep their traces short and wide. ` Put the input capacitor as close as possible to the device pins (VIN and GND). ` LX node is with high frequency voltage swing and should be kept in a small area. Keep analog components away from LX node to prevent stray capacitive noise pick-up. ` Connect feedback network behind the output capacitors. Keep the loop area small. Place the feedback components near the RT8016L. ` Connect all analog grounds to a common node and then connect the common node to the power ground behind the output capacitors. DS8016L-02 March 2011 RT8016L The inductor should be placed as close as possible to the switch pin to minimize the noise coupling into other circuits. LX node copper area should be minimized for reducing EMI. NC 8 Battery GND 1 7 FB/VOUT EN 2 6 GND VIN 3 5 LX L 4 COUT CIN NC GND CIN should be placed as closed as COUT should be connected possible to the VIN pin for good filtering. directly from Pin 7 to ground Figure 5. Fixed Voltage Regulator layout guide NC 8 R1 GND 1 7 FB/VOUT EN 2 6 GND VIN 3 5 LX C1 Battery CIN R2 VOUT L 4 COUT NC GND CIN should be placed as closed as The inductor should be placed as close as possible to the VIN pin for good filtering. possible to the switch pin to minimize the noise coupling into other circuits. LX node copper area should be minimized COUT should be connected directly from Pin 7 to ground for reducing EMI. Figure 6. Adjustable Voltage Regulator layout guide DS8016L-02 March 2011 www.richtek.com 11 RT8016L Supplier Table 1. Recommended Inductors Current DCR Inductance (µH) Dimensions(mm) Rating (mA) (mΩ) Series TAIYO YUDEN 2.2 1480 60 3.00 x 3.00 x 1.50 NR3015 GOTREND 2.2 1500 58 3.85 x 3.85 x 1.80 GTSD32 Sumida 2.2 1500 75 4.50 x 3.20 x 1.55 CDRH2D14 Sumida 4.7 1000 135 4.50 x 3.20 x 1.55 CDRH2D14 TAIYO YUDEN 4.7 1020 120 3.00 x 3.00 x 1.50 NR3015 GOTREND 4.7 1100 146 3.85 x 3.85 x 1.80 GTSD32 Table 2. Recommened Capacitors for CIN and COUT Supplier Capacitance (µF) Package Part Number TDK 4.7 0603 C1608JB0J475M MURATA 4.7 0603 GRM188R60J475KE19 TAIYO YUDEN 4.7 0603 JMK107BJ475RA TAIYO YUDEN 10 0603 JMK107BJ106MA TDK 10 0805 C2012JB0J106M MURATA 10 0805 GRM219R60J106ME19 MURATA 10 0805 GRM219R60J106KE19 TAIYO YUDEN 10 0805 JMK212BJ106RD www.richtek.com 12 DS8016L-02 March 2011 RT8016L Outline Dimension 2 1 2 1 DETAIL A Pin #1 ID and Tie Bar Mark Options Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated. Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.700 0.800 0.028 0.031 A1 0.000 0.050 0.000 0.002 A3 0.175 0.250 0.007 0.010 b 0.150 0.250 0.006 0.010 D 1.550 1.650 0.061 0.065 E 1.550 1.650 0.061 0.065 e L 0.400 0.350 0.016 0.450 0.014 0.018 W-Type 8L QFN 1.6x1.6 (COL) Package Richtek Technology Corporation Richtek Technology Corporation Headquarter Taipei Office (Marketing) 5F, No. 20, Taiyuen Street, Chupei City 5F, No. 95, Minchiuan Road, Hsintien City Hsinchu, Taiwan, R.O.C. Taipei County, Taiwan, R.O.C. Tel: (8863)5526789 Fax: (8863)5526611 Tel: (8862)86672399 Fax: (8862)86672377 Email: [email protected] Information that is provided by Richtek Technology Corporation is believed to be accurate and reliable. Richtek reserves the right to make any change in circuit design, specification or other related things if necessary without notice at any time. No third party intellectual property infringement of the applications should be guaranteed by users when integrating Richtek products into any application. No legal responsibility for any said applications is assumed by Richtek. DS8016L-02 March 2011 www.richtek.com 13