® RT8070 4A, 2MHz, Synchronous Step-Down Converter General Description Features The RT8070 is a high efficiency synchronous, step-down DC/DC converter. Its input voltage range is from 2.7V to 5.5V and provides an adjustable regulated output voltage from 0.8V to 5V while delivering up to 4A of output current. z High Efficiency : Up to 95% z Adjustable Frequency : 200kHz to 2MHz No Schottky Diode Required 0.8V Reference Allows Low Output Voltage Low Dropout Operation : 100% Duty Cycle Enable Function External Soft-Start Power Good Function RoHS Compliant and Halogen Free z z z The internal synchronous low on-resistance power switches increase efficiency and eliminate the need for an external Schottky diode. The default switching frequency is set at 2MHz, if the RT pin is left open. It can also be varied from 200kHz to 2MHz by adding an external resistor. Current mode operation with external compensation allows the transient response to be optimized over a wide range of loads and output capacitors. z z z z 维 圳 深 z z 75 ments of IPC/JEDEC J-STD-020. 鼎 北 强 大 际 YMDNN : Date Code 国 RT8070ZQW Suitable for use in SnPb or Pb-free soldering processes. 0 厦 RT8070ZSP : Product Number RT8070 ZSPYMDNN 诚 RoHS compliant and compatible with the current require- 室 5 0 28 RT8070ZSP 38 2 5 Richtek products are : 3 8 / Marking Information 5 1 Note : 0 5 4 4 1 2 LCD TV and Monitor Notebook Computers Distributed Power Systems IP Phones Digital Cameras 5 2 5 Lead Plating System Z : ECO (Ecological Element with Halogen Free and Pb free) ` z z Package Type SP : SOP-8 (Exposed Pad-Option 2) QW : WDFN-8L 3x3 (W-Type) ` z 富 RT8070 电 Applications 佳 Ordering Information 子 25 : Product Code 25 YM DNN YMDNN : Date Code 华 市 圳 深 Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS8070-07 November 2012 is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT8070 Pin Configurations (TOP VIEW) SS 2 EN 3 VIN 4 GND 8 PGOOD 7 FB 6 RT 5 LX 9 COMP SS EN VIN SOP-8 (Exposed Pad) PGOOD FB RT LX 8 1 3 GND COMP 6 4 9 5 2 7 WDFN-8L 3x3 Typical Application Circuit R3 100k 富 6 RT 圳 Chip Enable 深 3 EN COMP RCOMP 1 3 8 / GND 9 (Exposed Pad) SS 2 CSS 10nF 5 2 5 5 1 0 5 4 VOUT R1 4 1 2 FB 7 佳 8 PGOOD ROSC L 维 CIN 10µF PGOOD 子 电 RT8070 4 VIN LX 5 VIN 2.7V to 5.5V COUT R2 室 5 0 CCOMP 28 厦 Table 1. Recommended Components Selection for fSW = 1MHz VOUT (V) R1 (kΩ) 3.3 75 8 3 2 5 5 2.5 51 1.8 30 07 1.5 1.2 1 R2 (kΩ) RCOMP (kΩ) 24 33 大 C COMP (pF) L (μH) COUT (μF) 560 2 22 560 2 22 1.5 22 际 国 24 22 24 诚 560 13 560 1.5 22 11 560 1.5 22 8.2 560 1.5 22 21 24 12 24 6 24 15 鼎 北 强 华 市 圳 深 Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 is a registered trademark of Richtek Technology Corporation. DS8070-07 November 2012 RT8070 Functional Pin Description Pin No. SOP-8 WDFN-8L 3x3 (Exposed Pad) Pin Name Pin Function 1 1 COMP Error Amplifier Compensation Point. The current comparator threshold increases with this control voltage. Connect external compensation elements to this pin to stabilize the control loop. 2 2 SS Soft-Start Control Input. Connect a capacitor from SS to GND to set the soft-start period. A 10nF capacitor sets the soft-start period to 800μs (typ.). 3 3 EN Enable Control Input. Float or connect this pin to logic high for enable. Connect to GND for disable. 4 4 VIN 5 5 LX 6 6 RT 7 7 FB 8 8 PGOOD Power Good Indicator. This pin is an open drain logic output that is pulled to ground when the output voltage is not within ±12.5% of regulation point. 9 (Exposed Pad) 9 (Exposed Pad) GND Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. Power Input Supply. Decouple this pin to GND with a capacitor. Internal Power MOSFET Switches Output. Connect this pin to the inductor. Oscillator Resistor Input. Connect a resistor from this pin to GND sets the switching frequency. If this pin is floating, the frequency will be set at 2MHz internally. 子 电 维 佳 富 圳 深 38 2 5 5 7 0 COMP 华 FB 北 EA 市 VIN Slope Com OC Limit 10µA 圳 大 ISEN Output Clamp Driver LX Hiccup SS Control Logic 深 0.7V EN 厦 际 诚 鼎 室 5 0 28 国 SD 强 0.8V 3 8 / 5 2 5 RT OSC 4 1 2 Feedback. Receives the feedback voltage from a resistive divider connected across the output. 5 1 Function Block Diagram 0 5 4 Enable 0.4V P-G NISEN OTP UV GND N-MOSFET ILIM PGOOD Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS8070-07 November 2012 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT8070 Absolute Maximum Ratings z z z z z z (Note 1) 子 z z z z 电 维 佳 富 圳 深 Recommended Operating Conditions z z z −0.3V to 6V −0.3V to (VIN + 0.3V) −5V to 8.5V −0.3V to (VIN + 0.3V) 5A Supply Input Voltage, VIN ---------------------------------------------------------------------------------------LX Pin Switch Voltage --------------------------------------------------------------------------------------------<10ns ----------------------------------------------------------------------------------------------------------------Other I/O Pin Voltages -------------------------------------------------------------------------------------------LX Pin Switch Current --------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C SOP-8 (Exposed Pad) -------------------------------------------------------------------------------------------WDFN-8L 3x3 ------------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) SOP-8 (Exposed Pad), θJA --------------------------------------------------------------------------------------SOP-8 (Exposed Pad), θJC -------------------------------------------------------------------------------------WDFN-8L 3x3, θJA -------------------------------------------------------------------------------------------------WDFN-8L 3x3, θJC -------------------------------------------------------------------------------------------------Junction Temperature ---------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) -----------------------------------------------------------------------Storage Temperature Range ------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Model) --------------------------------------------------------------------------------------- 75°C/W 15°C/W 70°C/W 8.2°C/W 150°C 260°C −65°C to 150°C 0 5 4 4 1 2 83 / 5 2 室 5 0 2kV 28 (Note 4) 5 5 1 1.333W 1.429W 厦 Supply Input Voltage, VIN ---------------------------------------------------------------------------------------- 2.7V to 5.5V Junction Temperature Range ------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range ------------------------------------------------------------------------------------- −40°C to 85°C 大 38 2 5 Electrical Characteristics 75 0 Feedback Reference Voltage Min Typ Max Unit 0.784 0.8 0.816 V Active, VFB = 0.78V, Not Switching -- 460 -- Shutdown -- -- 10 VIN = 2.7V to 5.5V -- 0.1 -- %/V 0A < ILOAD < 4A -- 0.25 -- % gm -- 400 -- μA/V RT -- 0.3 -- Ω 强 华 市 圳 Output Voltage Load Regulation 深 Error Amplifier Trans-conductance Current Sense Trans-resistance Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 Test Conditions 北 VREF DC Bias Current Output Voltage Line Regulation 鼎 Symbol 国 诚 (VIN = 3.3V, TA = 25°C, unless otherwise specified) Parameter 际 μA is a registered trademark of Richtek Technology Corporation. DS8070-07 November 2012 RT8070 Parameter Symbol Switching Frequency Test Conditions Min Typ Max ROSC = 300k 0.8 1 1.2 Switching 0.2 -- 2 Unit MHz Logic-High VIH 1.6 -- -- Logic-Low VIL -- -- 0.4 Switch On-Resistance, High RDS(ON)_P ILX = 0.5A -- 110 180 mΩ Switch On-Resistance, Low RDS(ON)_N ILX = 0.5A -- 70 120 mΩ Peak Current Limit ILIM 4.7 5.8 -- A VIN Rising -- 2.4 -- VIN Falling -- 2.2 -- EN Input Voltage Under Voltage Lockout Threshold RT Shutdown Threshold VRT VRT Rising Soft-Start Period tSS CSS = 10nF 子 -- 电 PGOOD Trip Threshold 维 V V VIN − 0.7 VIN − 0.4 V 0 5 4 -- 800 -- μs -- 87.5 -- %VOUT 4 1 2 Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are 佳 stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in 富 3 8 / 室 5 0 the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may 圳 affect device reliability. Note 2. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. θJC is 深 5 2 5 measured at the exposed pad of the package. Note 3. Devices are ESD sensitive. Handling precaution is recommended. 5 1 厦 Note 4. The device is not guaranteed to function outside its operating conditions. 38 2 5 大 际 国 诚 75 0 28 鼎 北 强 华 市 圳 深 Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS8070-07 November 2012 is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT8070 Typical Operating Characteristics Efficiency vs. Output Current Output Voltage vs. Output Current 100 1.130 90 1.125 1.120 1.115 Output Voltage (V) Efficiency (%) 80 70 60 50 40 30 1.110 1.105 1.100 1.095 1.090 1.085 20 1.080 10 电 0 1.070 0 0.5 1 1.5 2 2.5 3 3.5 4 0 维 Output Current (A) 佳 Switching Frequency vs. Temperature 富 1.03 圳 1.02 深 1.01 1.00 0.98 0.97 VIN = 5V, VOUT = 1.1V, IOUT = 0.6A, RRT = 330kΩ 0.95 2 5 0.94 -50 -25 0 75 25 50 75 0 2.8 125 VIN = 5V, VOUT = 1.1V 0.76 -50 -25 0 25 50 75 100 125 Temperature (°C) 1.5 1.4 Falling 深 2.2 大 Enable Voltage vs. Temperature Rising 圳 2.3 4 室 5 0 际 0.77 Enable Voltage (V) 市 3.5 1.6 华 2.4 0.78 鼎 强 2.5 3 厦 0.79 北 2.6 2.5 28 0.80 VIN UVLO vs. Temperature 2.7 2 4 4 0.81 国 诚 100 Temperature (°C) 0.82 25 50 1.5 Output Current (A) /8 38 0.96 1 1 2 3 0.83 5 5 1 0.99 0.5 VIN = 5V, VOUT = 1.1V, IOUT = 0A to 4A Reference Voltage vs. Temperature 0.84 Reference Voltage (V) Switching Frequency (MHz)1 1.04 VIN UVLO (V) 子 1.075 VIN = 5V, VOUT = 1.1V, IOUT = 0A to 4A 2.1 1.3 1.2 Rising 1.1 Falling 1.0 0.9 2.0 0.8 1.9 0.7 1.8 0.6 -50 -25 0 25 50 75 100 Temperature (°C) Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 125 -50 -25 0 25 50 75 100 125 Temperature (°C) is a registered trademark of Richtek Technology Corporation. DS8070-07 November 2012 RT8070 Switching Load Transient Response VOUT (200mV/Div) VLX (5V/Div) IOUT (2A/Div) VOUT (10mV/Div) VIN = 5V, VOUT = 1.1V, IOUT = 1A to 4A, RCOMP = 10kΩ, CCOMP = 560pF 子 电 Time (100μs/Div) 维 佳 Power On from VIN 富 圳 VIN (5V/Div) 深 VOUT (1V/Div) -2 55 07 鼎 强 市 圳 VIN = 5V, VOUT = 1.1V, IOUT = 4A Time (500μs/Div) Copyright © 2012 Richtek Technology Corporation. All rights reserved. November 2012 28 厦 VIN = 5V, VOUT = 1.1V, IOUT = 4A, EN = High Time (5ms/Div) Power Off from EN VEN (5V/Div) VOUT (1V/Div) 深 DS8070-07 国 室 5 0 大 际 北 Power On from EN VPGOOD (5V/Div) IOUT (5A/Div) VPGOOD (5V/Div) IOUT (5A/Div) 诚 华 VEN (5V/Div) VOUT (1V/Div) VOUT (1V/Div) VIN = 5V, VOUT = 1.1V, IOUT = 4A, EN = High Time (2.5ms/Div) 4 1 2 3 8 / 5 2 5 38 0 5 4 Time (500ns/Div) Power Off from VIN VIN (5V/Div) 5 1 VPGOOD (5V/Div) IOUT (5A/Div) VIN = 5V, VOUT = 1.1V, IOUT = 4A VPGOOD (5V/Div) IOUT (5A/Div) VIN = 5V, VOUT = 1.1V, IOUT = 4A Time (250μs/Div) is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT8070 Application Information Soft-Start The basic IC 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. Main Control Loop The IC contains an external soft-start clamp that gradually raises the output voltage. The soft-start timing is programmed by the external capacitor between SS pin and GND. The chip provides an internal 10μA charge current for the external capacitor. If 10nF capacitor is used to set the soft-start, the period will be 800μs (typ.). During normal operation, the internal upper power switch (P-MOSFET) is turned on at the beginning of each clock cycle. Current in the inductor increases until the peak inductor current reaches the value defined by the output voltage (VCOMP) of the error amplifier. The error amplifier adjusts its output voltage by comparing the feedback signal from a resistive voltage-divider on the FB pin with an internal 0.8V reference. When the load current increases, it causes a reduction in the feedback voltage relative to the reference. The error amplifier increases its output voltage until the average inductor current matches the new load current. When the upper power MOSFET shuts off, the lower synchronous power switch (N-MOSFET) turns on until the beginning of the next clock cycle. Power Good Output The power good output is an open-drain output and requires a pull up resistor. When the output voltage is 12.5% above or 12.5% below its set voltage, PGOOD will be pulled low. It is held low until the output voltage returns to within the allowed tolerances once more. During soft-start, PGOOD is actively held low and is only allowed to transition high when soft-start is over and the output voltage reaches 87.5% of its set voltage. 子 电 维 佳 富 圳 深 38 2 5 R1 ) R2 where VREF equals to 0.8V typical. 0 鼎 The resistive voltage-divider allows the FB pin to sense a fraction of the output voltage as shown in Figure 1. 北 强 VOUT 华 市 R1 FB 圳 RT8070 深 室 5 0 28 Selection of the operating frequency is a tradeoff between efficiency and component size. Higher frequency operation allows the use of smaller inductor and capacitor values. Lower frequency operation improves efficiency by reducing internal gate charge and switching losses but requires larger inductance and/or capacitance to maintain low output ripple voltage. 厦 大 际 国 诚 75 3 8 / 5 2 5 The output voltage is set by an external resistive voltagedivider according to the following equation : VOUT = VREF × (1+ 4 1 2 Operating Frequency 5 1 Output Voltage Setting 0 5 4 R2 The operating frequency of the IC is determined by an external resistor , ROSC, that is connected between the RT pin and ground. The value of the resistor sets the ramp current that is used to charge and discharge an internal timing capacitor within the oscillator. The practical switching frequency ranges from 200kHz to 2MHz. However, when the RT pin is floating, the internal frequency is set at 2MHz. Determine the RT resistor value by examining the curve below. Please notice the minimum on time is about 90ns. GND Figure 1. Setting the Output Voltage Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 is a registered trademark of Richtek Technology Corporation. DS8070-07 November 2012 RT8070 Switching Frequency (MHz)1 2.4 and the power is supplied by a wall adapter through long wires, a load step at the output can induce ringing at the input. 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. 2.0 1.6 1.2 0.8 Slope Compensation and Peak Inductor Current Slope compensation provides stability in constant frequency architectures by preventing sub- harmonic oscillations at duty cycles greater than 50%. It is accomplished internally by adding a compensating ramp to the inductor current signal. Normally, the peak inductor current is reduced when slope compensation is added. For the IC, however, separated inductor current signal is used to monitor over current condition, so the maximum output current stays relatively constant regardless of the duty cycle. 0.4 0.0 0 300 600 900 1200 1500 1800 2100 子 RRT (kΩ) Figure 2. Switching Frequency vs. RRT Resistor 电 Inductor Selection 维 佳 For a given input and output voltage, the inductor value and operating frequency determine the ripple current. The ripple current, DIL, increases with higher VIN and decreases with higher inductance ⎤ ⎡V ⎤ ⎡ V ΔIL = ⎢ OUT ⎥ ⎢1 − OUT ⎥ VIN ⎦ ⎣ f ×L ⎦ ⎣ 富 圳 深 38 0 鼎 北 强 华 市 圳 Using Ceramic Input and Output Capacitors 深 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 Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS8070-07 November 2012 室 5 0 28 A Hiccup Mode Under Voltage Protection (UVP) function is provided for the IC. When the FB voltage drops below half of the feedback reference voltage, VFB, the UVP function is triggered to auto soft-start the power stage until this event is cleared. The Hiccup Mode UVP reduces the input current in short circuit conditions, but will not be triggered during soft-start process. 厦 大 际 国 诚 75 3 8 / 5 2 5 5 1 2 5 4 1 2 Hiccup Mode Under Voltage Protection Having a lower ripple current reduces not only the ESR losses in the output capacitors but also the output voltage ripple. Highest efficiency operation is achieved by reducing ripple current at low frequency, but attaining this goal requires a large inductor. For the ripple current selection, the value of ΔIL = 0.4(IMAX) is a reasonable starting point. The largest ripple current occurs at the highest VIN. To guarantee that the ripple current stays below a specified maximum value, the inductor value needs to be chosen according to the following equation : ⎡ VOUT ⎤ ⎡ ⎤ V L= ⎢ ⎥ ⎢1− OUT ⎥ ⎣⎢ f × ΔIL(MAX) ⎦⎥ ⎣⎢ VIN(MAX) ⎦⎥ 0 5 4 Under Voltage Lockout Threshold The RT8070 includes an input under voltage lockout protection (UVLO) function. If the input voltage exceeds the UVLO rising threshold voltage, the converter will reset and prepare the PWM for operation. However, if the input voltage falls below the UVLO falling threshold voltage during normal operation, the device will stop switching. The UVLO rising and falling threshold voltage has a hysteresis to prevent noise caused reset. Thermal 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 is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT8070 Layout Considerations maximum power dissipation can be calculated by the following formula : Follow the PCB layout guidelines for optimal performance of the IC. 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. ` Connect the terminal of the input capacitor(s), CIN, as close to the VIN pin as possible. This capacitor provides the AC current into the internal power MOSFETs. For recommended operating condition specifications, the maximum junction temperature is 125°C. The junction to ambient thermal resistance, θJA, is layout dependent. For SOP-8 (Exposed Pad) packages, the thermal resistance, θJA, is 75°C/W on a standard JEDEC 51-7 four-layer thermal test board. For WDFN-8L 3x3 packages, the thermal resistance, θJA, is 70°C/W on a standard JEDEC 51-7 four-layer thermal test board. The maximum power dissipation at TA = 25°C can be calculated by the following formulas : ` LX node experiences high frequency voltage swings so should be kept within a small area. ` Keep all sensitive small signal nodes away from the LX node to prevent stray capacitive noise pick up. ` Connect the FB pin directly to the feedback resistors. The resistive voltage divider must be connected between VOUT and GND. 电 维 PD(MAX) = (125°C − 25°C) / (75°C/W) = 1.333W for SOP-8 (Exposed Pad) package 圳 深 PD(MAX) = (125°C − 25°C) / (70°C/W) = 1.429W for WDFN-8L 3x3 package 52 5- 75 0 鼎 北 WDFN-8L 3x3 强 RCOMP 8 室 5 0 EN VIN GND VIN PGOOD 7 GND 3 6 9 4 5 厦 CIN FB RT L1 COUT 大 R1 LX VOUT 际 国 R2 28 2 SS CSS 诚 Four Layer PCB COMP Place the feedback resistors as close to the IC as possible Place the compensation components as close to the IC as possible GND 华 R2 CCOMP 市 RCOMP 圳 0 25 CSS 75 100 CIN 125 Ambient Temperature (°C) Figure 3. Derating Curve of Maximum Power Dissipation COMP SS EN VIN 8 1 3 6 4 9 5 2 7 PGOOD FB RT LX R1 ROSC VOUT GND L1 GND 50 GND ROSC LX should be connected to inductor by wide and short trace, and keep sensitive components away from this trace (a) For SOP-8 (Exposed Pad) package SOP-8 (Exposed Pad) 深 VOUT Place the input and output capacitors as close to the IC as possible GND Maximum Power Dissipation (W)1 1.5 1.4 1.3 1.2 1.1 1.0 0.9 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 8 3 2 4 1 2 83 5/ 5 1 Place the feedback resistors as close to the IC as possible GND CCOMP The maximum power dissipation depends on the operating ambient temperature for fixed T J(MAX) and thermal resistance, θJA. The derating curves in Figure 3 allow the designer to see the effect of rising ambient temperature on the maximum power dissipation. 0 5 4 Place the compensation components as close to the IC as possible 佳 富 子 VIN COUT VOUT Place the input and output capacitors as close to the IC as possible LX should be connected to inductor by wide and short trace, and keep sensitive components away from this trace (b) For WDFN-8L 3x3 package Figure 4. PCB Layout Guide Copyright © 2012 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 is a registered trademark of Richtek Technology Corporation. DS8070-07 November 2012 RT8070 Outline Dimension H A M EXPOSED THERMAL PAD (Bottom of Package) Y J B X F 子 电 0 5 4 C I 维 佳 D Dimensions In Millimeters 富 Symbol Min 圳 A 深 B C 4.000 Option 2 华 强 X Y 0.157 28 1.346 0.047 0.170 0.254 0.007 0.010 0.000 0.152 0.000 0.006 5.791 6.200 0.228 0.244 1.270 0.016 0.050 0.069 2.300 0.079 0.091 2.000 2.300 0.079 0.091 2.100 2.500 0.083 0.098 3.000 3.500 0.118 0.138 厦 大 际 国 诚 鼎 2.000 北 Y 0.150 0.013 0.406 X 0.197 0.510 38 Option 1 0.189 0.053 5 1 M 5/ 室 5 0 Max 1.753 1.194 2 5 Min 52 1.346 F J 市 3.810 0.330 I 5 7 0 5.004 D H 83 Max 4.801 4 1 2 Dimensions In Inches 0.020 0.053 8-Lead SOP (Exposed Pad) Plastic Package 圳 深 Copyright © 2012 Richtek Technology Corporation. All rights reserved. DS8070-07 November 2012 is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT8070 D2 D L E E2 SEE DETAIL A 1 e b 2 1 2 1 A A1 A3 子 电 维 佳 富 圳 深 A Min Max 0.700 0.800 A1 0.000 A3 0.175 b 0.200 D 5- D2 5 7 0 3 8 / 1.350 北 e 强 L 0.300 0.008 0.012 0.116 0.120 0.083 0.093 3.050 0.116 0.120 1.600 0.053 0.063 0.425 华 大 际 国 诚 鼎 厦 0.007 2.350 E2 0.031 0.250 2.100 室 5 0 28 0.028 0.000 3.050 2.950 Max 0.050 2.950 E Min 55 23 4 1 2 Dimensions In Inches 25 81 0 5 4 Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated. Dimensions In Millimeters Symbol DETAIL A Pin #1 ID and Tie Bar Mark Options 0.650 0.002 0.010 0.026 0.525 0.017 0.021 W-Type 8L DFN 3x3 Package 市 圳 深 Richtek Technology Corporation 5F, No. 20, Taiyuen Street, Chupei City Hsinchu, Taiwan, R.O.C. Tel: (8863)5526789 Richtek products are sold by description only. Richtek reserves the right to change the circuitry and/or specifications without notice at any time. Customers should obtain the latest relevant information and data sheets before placing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Richtek or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Richtek or its subsidiaries. www.richtek.com 12 DS8070-07 November 2012