RT8450BGQW

® RT8450/B High Voltage Multi-Topology LED Driver General Description Features The RT8450/B is a current mode PWM regulator for LED driving applications. With an 1.5A switch on board and wide input (4.5V to 40V) and/or output (up to 50V)ranges the RT8450/B can operate in any of the three common topologies : Buck, Boost or Buck-Boost.  High Voltage : VIN Up to 40V, VOUT Up to 50V  1.5A Switch Current Buck, Boost or Buck-Boost Operation Current Mode PWM with 800kHz (RT8450) and 500kHz (RT8450B) Switching Frenquency Easy Dimming : Analog, PWM Digital or PWM Converting to Analog with One External Capacitor Programmable Soft-Start to Avoid Inrush Current Programmable Over Voltage Protection to Limit Output Voltage VIN Under Voltage Lockout and Thermal Shutdown RoHS Compliant and Halogen Free With 800k/500kHz operating frequency, the external PWM inductor and input/output capacitors can all be small. High efficiency is achieved by a 190mV current sensing.      Dimming can be done either analog or PWM signal. An unique built-in clampping comparator and filtering resistor allow easy low noise analog dimming conversion from PWM signal with only one external capacitor. The RT8450/B is available in a TSSOP-16 (Exposed Pad) and WDFN-12L 3x3 packages. Ordering Information RT8450/B Package Type CP : TSSOP-16 (Exposed Pad) QW : WDFN-12L 3x3 (W-Type) (Exposed Pad-Option 1) Lead Plating System G : Green (Halogen Free and Pb Free) Switching Frequency 500kHz 800kHz Note : Richtek products are :   Applications    GPS, Portable DVD Backlight Desk Lights and Room Lighting Industrial Display Backlight Pin Configurations (TOP VIEW) ISP ISN VC ACTL DCTL EN OVP SS 2 3 4 5 6 7 8 16 15 14 13 GND 12 17 11 10 9 VCC1 VCC2 SW SW GND GND GND GND TSSOP-16 (Exposed Pad) RoHS compliant and compatible with the current requirements of IPC/JEDEC J-STD-020.   Suitable for use in SnPb or Pb-free soldering processes. Marking Information For marking information, contact our sales representative directly or through a Richtek distributor located in your area. Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8450/B-05 August 2014 ISP ISN VC ACTL DCTL EN 1 2 3 4 5 6 GND 13 12 11 10 9 8 7 VCC2 VCC1 SW GND SS OVP WDFN-12L 3x3 is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT8450/B Typical Application Circuit VIN 4.5V to 40V C1 RT8450/B 5V VCCx ISP EN ISN R3 R4 DCTL PWM Dimming control OVP VC R1 10k ACTL C3 10nF C5 GND SS C2 3.3nF R2 190mV SW L 20µH C4 0.47µF Figure 1. PWM to Analog Dimming Buck Configuration VIN 4.5V to 40V C1 RT8450/B Analog Dimming VCCx ISP ACTL ISN R2 190mV R3 R4 DCTL OVP EN 5V GND VC R1 10k C2 3.3nF C4 L 15µH SS SW C3 10nF Figure 2. Analog Dimming Buck Configuration VIN 4.5V to 40V C1 RT8450/B PWM Dimming control 5V VCCx ISP ACTL ISN DCTL OVP EN GND VC R1 10k C2 3.3nF R3 R4 C4 L 15µH SS C3 10nF R2 190mV SW Figure 3. PWM Dimming Buck Configuration Through ACTL Pin Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 is a registered trademark of Richtek Technology Corporation. DS8450/B-05 August 2014 RT8450/B L 15µH VIN 4.5V to 40V C1 C5 1µF RT8450/B 5V PWM Dimming control VCCx SW EN ISP DCTL ISN R2 190mV VC R1 10k C2 3.3nF SS ACTL C3 10nF R3 OVP GND VOUT R4 C4 0.47µF Figure 4. PWM to Analog Dimming Boost Configuration C5 L VIN 4.5V to 40V VOUT 15µH C1 RT8450/B VCCx 5V PWM Dimming control SW EN ISP DCTL ISN R2 190mV VC R1 10k C2 3.3nF C3 10nF SS OVP ACTL GND R3 VOUT R4 C4 0.47µF Figure 5. PWM to Analog Dimming Buck-Boost Configuration Functional Pin Description Pin No. Pin Name Pin Function TSSOP-16 WDFN-12L 3x3 (Exposed Pad) 1 1 ISP Current Sense Amplifier Positive Input. Current Sense Amplifier Negative Input. Voltage threshold between 2 2 ISN ISP and ISN is 190mV. PWM Boost Converter Loop Compensation Node. 3 3 VC Analog Dimming Control. Effective programming range is between 4 4 ACTL 0.3V and 1.2V. By Adding a 0.47F Filtering Capacitor on ACTL Pin, the PWM dimming signal on DCTL pin will be averaged and converted into 5 5 DCTL analog dimming signal on ACTL pin. VACTL = 1.2V x PWM dimming duty cycle . 6 6 EN Chip Enable (Active High), when low chip is in shutdown mode. Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8450/B-05 August 2014 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT8450/B Pin No. Pin Name TSSOP-16 (Exposed Pad) WDFN-12L 3x3 7 7 OVP 8 8 SS 9, 10, 11, 12, 9, 17 (Exposed Pad) 13 (Exposed Pad) 13, 14 GND 10 SW Pin Function Over voltage protection. PWM boost converter turns off when VOVP goes higher than 1.2V. Soft-Start Pin, a capacitor of at least 10nF is required for softstart. Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. PWM Boost Converter Switch Node. 15 12 VCC2 Bipolar Power Switch Base Current Supply. VCC2 can be connected either to VCC1 or to a separate lower voltage, as low as 3V, for better system efficiency and/or heat concern. A good bypass is necessary. 16 11 VCC1 Power Supply of the Chip. For good bypass, a low ESR capacitor is required. Function Block Diagram SW VCC1 OSC - 4.5V VCC2 S + R OVP + 1.2V R - EN + Shutdown - + - 1.4V VC ISN ISP GM + 6µA SS 1.2V DCTL + + - - GND ACTL VISP – VISN (mV) 190 0 0.3 1.2 VACTL (V) Figure 6 Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 is a registered trademark of Richtek Technology Corporation. DS8450/B-05 August 2014 RT8450/B Absolute Maximum Ratings           (Note 1) Supply Input Voltage, VCC1, VCC2 ---------------------------------------------------------------------------------------- 45V SW Pin Voltage at Switching Off, ISP, ISN ---------------------------------------------------------------------------- 55V DCTL, ACTL, OVP Pin Voltage ------------------------------------------------------------------------------------------ 8V (Note 2) EN Pin Voltage --------------------------------------------------------------------------------------------------------------- 20V Power Dissipation, PD @ TA = 25°C TSSOP-16 --------------------------------------------------------------------------------------------------------------------- 2.66W WDFN-12L 3x3 --------------------------------------------------------------------------------------------------------------- 1.667W Package Thermal Resistance (Note 3) TSSOP-16, θJA --------------------------------------------------------------------------------------------------------------- 47°C/W WDFN-12L 3x3, θJA --------------------------------------------------------------------------------------------------------- 60°C/W WDFN-12L 3x3, θJC --------------------------------------------------------------------------------------------------------- 8.2°C/W Junction Temperature ------------------------------------------------------------------------------------------------------- 150°C Lead Temperature (Soldering, 10 sec.) --------------------------------------------------------------------------------- 260°C Storage Temperature Range ---------------------------------------------------------------------------------------------- −65°C to 150°C ESD Susceptibility (Note 4) HBM (Human Body Mode) ------------------------------------------------------------------------------------------------ 2kV MM (Machine Mode) -------------------------------------------------------------------------------------------------------- 200V Recommended Operating Conditions   (Note 5) Junction Temperature Range ---------------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range ---------------------------------------------------------------------------------------------- −40°C to 85°C Electrical Characteristics (VCC1 = VCC2 = 12V, No Load on any Output, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Overall Supply Voltage VCC1 4.5 -- 40 V Supply Voltage VCC2 for Switch Base Drive VCC2 3 -- 40 V Supply Current IVCC1 VC  0.4V (Switching off) -- 4 6 mA Supply Current IVCC2 VCC1 = VCC2 = 24V, I SW  1A -- Shutdown Current ISHDN_VCC1 VEN  0.7V -- 12 -- A Shutdown Threshold VEN 1 1.4 -- V -- -- 0.5 A 170 190 210 mV EN Input Current VEN = 3V ISW/70 ISW/40 A Current Sense Amplifier Input Threshold (VISP  VISN) 4.5V  common mode  50V Input Current IISP VISP = 24V -- 100 -- A Input Current IISN VISN = 24V -- 40 -- A Output Current IVC 2.4V > VC > 0.2V -- 20 -- A -- 0.7 -- V VC Threshold for PWM Switch Off Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8450/B-05 August 2014 is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT8450/B Parameter Symbol Test Conditions Min Typ Max Unit -- -- 3 A -- 0.2 -- V -- -- 0.5 A RT8450 600 800 1000 kHz RT8450B RT8450 400 -- 500 80 600 -- kHz RT8450B -- 86 -- -- 250 -- ns -- 0.4 -- V 1.25 1.5 -- A -- 1.2 -- V LED Dimming Analog Dimming ACTL Pin Input Current LED Current Off Threshold at ACTL DCTL Input Current IACTL 0.3V  VACTL  1.2V VACTL IDCTL 0.3V  VDCTL  6V PWM BOOST Converter Switching Frequency Maximum Duty Cycle (Note 6) fSW DMAX Minimum on Time SW On-Voltage VSW SW Current Limit ILIM_SW ISW = 0.5A % OVP and Soft Start OVP Threshold VOVP OVP Input Current IOVP 0.7V  VOVP  1.5V -- -- 0.5 A Soft Start SS Pin Current ISS VSS  2V -- 6 -- A Note 1. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Note 2. If connected with a 20kΩ serial resistor, ACTL and DCTL can go up to 40V. Note 3. θJA is measured in the natural convection at TA = 25°C on a high effective four layers thermal conductivity test board of JEDEC 51-7 thermal measurement standard. Note 4. Devices are ESD sensitive. Handling precaution is recommended. Note 5. The device is not guaranteed to function outside its operating conditions. Note 6. When the natural maximum duty cycle of the switching frequency is reached, the switching cycle will be skipped (not reset) as the operating condition requires to effectively stretch and achieve higher on cycle than the natural maximum duty cycle set by the switching frequency. Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 is a registered trademark of Richtek Technology Corporation. DS8450/B-05 August 2014 RT8450/B Typical Operating Characteristics (ISP – ISN) Voltage vs ACTL Input Voltage 200 198 180 (ISP – ISN) Voltage (mV) (ISP – ISN) Voltage (mV) (ISP – ISN) Voltage vs. Input Voltage 200 196 194 192 190 188 186 184 182 4 8 12 16 20 24 28 32 36 140 120 100 80 60 40 20 VIN = 24V, VACTL = 1.5V 180 160 VIN = 24V 0 40 0.2 0.5 Input Voltage (V) Supply Current vs. Input Voltage 1.4 100 4.5 95 4 90 3.5 Efficiency (%) Supply Current (mA) 1.1 Efficiency vs. Input Voltage 5 3 2.5 2 1.5 85 80 75 70 1 65 0.5 VIN = 24V, VACTL = 0V Buck, VOUT = 21V, ILED = 350mA 0 60 4 8 12 16 20 24 28 32 36 40 22 24 26 Input Voltage (V) 28 30 32 34 36 38 40 Input Voltage (V) Efficiency vs. Input Voltage Efficiency vs. Input Voltage 100 100 90 90 80 80 70 70 Efficiency (%) Efficiency (%) 0.8 ACTL Input Voltage (V) 60 50 40 30 20 60 50 40 30 20 10 Boost, VOUT = 21V, ILED = 350mA 0 6 8 10 12 14 16 18 Input Voltage (V) Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8450/B-05 August 2014 20 10 Buck~Boost, VOUT = 10.5V, ILED = 350mA 0 6 8 10 12 14 16 18 Input Voltage (V) is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT8450/B LED Current vs. ACTL 600 500 500 LED Current (mA) LED Current (mA) LED Current vs. DCTL Duty 600 400 300 200 100 0 10 20 30 40 50 60 70 80 90 300 200 100 VIN = 24V, f = 1kHz VDCTL = 0V to 3V, R2 = 0.35Ω 0 400 VIN = 24V, R2 = 0.35Ω 0 0.2 100 0.4 0.6 DCTL Duty (%) 1 1.2 1.4 ACTL (V) OVP vs. Input Voltage OVP vs. Temperature 1.23 1.220 1.22 OVP (V) 1.215 OVP (V) 0.8 1.210 1.205 1.21 1.2 1.19 VIN = 24V 1.200 1.18 4 10 16 22 28 34 40 -50 -25 0 25 50 75 100 125 Temperature (°C) Input Voltage (V) Current Limit vs. Input Voltage ACTL-Off vs. Temperature 1.60 0.2000 0.1975 Current Limit (A) ACTL-Off (V) 0.1950 0.1925 0.1900 0.1875 1.55 1.50 1.45 0.1850 0.1825 VIN = 24V 0.1800 -50 -25 0 25 50 75 100 Temperature (°C) Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 125 1.40 4 10 16 22 28 34 40 Input Voltage (V) is a registered trademark of Richtek Technology Corporation. DS8450/B-05 August 2014 RT8450/B Switching Frequency vs. Input Voltage SS pin Current vs. Temperature 10 9 RT8450 800 700 600 RT8450B 500 Soft Start Current (uA) Switching Frequency (kHz)1 900 8 7 6 5 4 3 2 1 400 VIN = 12V, CSS= 0.1μF 0 4 10 16 22 28 34 40 -50 0 25 50 75 100 Power On from EN Power On from EN VIN (10V/Div) VEN (5V/Div) VIN (20V/Div) VEN (5V/Div) VOUT (10V/Div) IOUT (100mA/Div) VOUT (10V/Div) IOUT (100mA/Div) VIN = 24V CSS = 0.1μF, 12 LEDs Boost Time (250μs/Div) Time (250μs/Div) Line Transient Response Line Transient Response VIN (10V/Div) VIN (10V/Div) VOUT_ac (20V/Div) VOUT_ac (20V/Div) VIN = 12V to 15V 10 LEDs Boost RISET = 0.68Ω IOUT (100mA/Div) Time 1ms/Div) Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8450/B-05 August 2014 125 Temperature (°C) Input Voltage (V) VIN = 14V CSS = 0.1μF, 10 LEDs Boost -25 VIN = 20V to 24V 12 LEDs Boost RISET = 0.68Ω IOUT (100mA/Div) Time 1ms/Div) is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT8450/B Line Transient Response VIN (10V/Div) VOUT_ac (20V/Div) VIN = 21V to 24V 6 LEDs Buck RISET = 0.25Ω IOUT (100mA/Div) Time 1ms/Div) Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 is a registered trademark of Richtek Technology Corporation. DS8450/B-05 August 2014 RT8450/B Application Information The RT8450/B is specifically designed to be operated in buck, buck -boost and boost converter applications. This device uses a fixed frequency, current mode control scheme to provide excellent line and load regulation. The control loop has a current sense amplifier to sense the voltage between the ISP and ISN pins and provides an output voltage at the VC pin. A PWM comparator then turns off the internal power switch when the sensed power switch current exceeds the compensated VC pin voltage. The power switch will not reset by the oscillator clock in each cycle. If the comparator does not turn off the switch in a cycle, the power switch is on for more than a full switching period until the comparator is tripped. In this manner, the programmed voltage across the sense resistor is regulated by the control loop. The current through the sense resistor is set by the programmed voltage and the sense resistance. The voltage across the sense resistor can be programmed by either the analog or PWM signals at the ACTL pin, or the PWM signal at the DCTL pin. The protection schemes in the RT8450/B include over temperature, input voltage under voltage, output voltage over-voltage, and switch current limit. Loop Compensation The RT8450/B has an external compensation pin (VC) allowing the loop response optimized for specific application. An external resistor in series with a capacitor is connected from the VC pin to GND to provide a pole and a zero for proper loop compensation. The recommended compensation resistance and capacitance for the RT8450/B are 10k and 3.3nF. Soft-Start The soft-start of the RT8450/B can be achieved by connecting a capacitor from the SS pin to GND. The builtin soft-start circuit reduces the start-up current spike and output voltage overshoot. The soft-start time is determined by the external capacitor charged by an internal 6μA constant charging current. The SS pin directly limits the rate of voltage rise on the VC pin, which in turn limits the peak switch current. The value of the soft-start capacitor is user-defined to satisfy the designer’ s requirement. Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8450/B-05 August 2014 LED Current Setting The LED current could be calculated by the following equation : ILED,MAX = V(ISP-ISN) R2 Where V(ISP-ISN) is the voltage between ISP and ISN (190mV typ. if ACTL or DCTL dimming is not applied) and the R2 is the resister between ISP and ISN. Brightness / Dimming Control The RT8450/B features both analog and digital dimming control. Analog dimming is linearly controlled by an external voltage (0.3V < VACTL < 1.2V). With an on-chip output clamping amplifier and a resistor, PWM dimming signal fed at DCTL pin can be easily low-pass filtered to an analog dimming signal with one external capacitor from ACTL pin to GND for noise-free PWM dimming. A very high contrast ratio true digital PWM dimming can be achieved by driving ACTL pin with a PWM signal from 100Hz to 10kHz. Output Over Voltage Setting The RT8450/B is equipped with over voltage protection (OVP) function. When the voltage at OVP pin exceeds a threshold of approximately1.2V, the power switch is turned off. The power switch can be turned on again once the voltage at OVP pin drops below 1.2V. For the Boost Application, the output voltage could be clamped at a certain voltage level. The OVP voltage can be set by the following equation : R3 VOUT,OVP = 1.2 x (1 + ) R4 Where R3 and R4 are the voltage divider from VOUT to GND with the divider center node connected to OVP pin. Current-Limit Protection The RT8450/B can limit the peak switch current by the internal over current protection feature. In normal operation, the power switch is turned off when the switch current hits the loop-set value. The over current protection function will turn off the power switch independent of the loop control when the peak switch current reaches around 1.5A. is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT8450/B Over Temperature Protection Schottky Diode Selection The RT8450/B has over temperature protection (OTP) function to prevent the excessive power dissipation from overheating. The OTP function will shut down switching operation when the die junction temperature exceeds 150°C. The chip will automatically start to switch again when the die junction temperature cools off. The Schottky diode, with low forward voltage drop and fast switching speed, is necessary for the RT8450/B applications. In addition, power dissipation, reverse voltage rating and pulsating peak current are the important parameters of the Schottky diode that must be considered. Choose a suitable Schottky diode whose reverse voltage rating is greater than the maximum output voltage. The diode’ s average current rating must exceed the average output current. The diode conducts current only when the power switch is turned off (typically less than 50% duty cycle). Inductor Selection Choose an inductor that can handle the necessary peak current without saturating, and ensure that the inductor has a low DCR (copper-wire resistance) to minimize I2R power losses. A 4.7μH to 10μH inductor will meet the demand for most of the RT8450/B applications. Inductor manufacturers specify the maximum current rating as the current where the inductance falls to certain percentage of its nominal value typically 65%. In Boost application where the transition between discontinuous and continuous modes occurs, the value of the required output inductor (L), can be approximated by the following equation : V x D x (1-D)2 L = OUT 2 x IOUT x f The Duty Cycle (D) could be calculated as follows : V - VIN D = OUT VOUT Where VOUT = maximum output voltage. VIN = minimum input voltage. f = operating frequency. IOUT = sum of current from all LED strings. The boost converter operates in discontinuous mode over the entire input voltage range can have inductor value L1 less than the calculated value L by the formula above. With an inductance value L2 greater than L, the converter will operate in continuous mode at the minimum input voltage and maybe operate in discontinuous mode at higher voltages. The inductor must be selected with a saturation current rating greater than the peak current provided by the following equation : V xI V xDxT IPEAK = OUT LED + IN η x VIN 2xL Where ç is the efficiency of the power converter. Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 Capacitor Selection The input capacitor reduces current spikes from the input supply and minimizes noise injection to the converter. For most RT8450/B applications, a 4.7μF ceramic capacitor is sufficient. A value higher or lower may be used depending on the noise level from the input supply and the input current to the converter. In Boost Application, the output capacitor is typically a ceramic capacitor and is selected based on the output voltage ripple requirements. The minimum value of the output capacitor COUT is approximately given by the following equation : I xDxT COUT = LED VRIPPLE Layout Consideration PCB layout is very important to design power switching converter circuits. Some recommended layout guidelines are suggested as follows:  The power components L1, D1, CVIN, and COUT must be placed as close to each other as possible to reduce the ac current loop area. The PCB trace between power components must be as short and wide as possible due to large current flow through these traces during operation.  Place L1 and D1 connected to SW pin as close as possible. The trace should be as short and wide as possible.  The input capacitors CVCC1 and CVCC2 must be placed as close to VCC1 and VCC2 pin as possible. is a registered trademark of Richtek Technology Corporation. DS8450/B-05 August 2014 RT8450/B  Place the compensation components to the VC pin as close as possible to avoid noise pick up. Place these components as close as possible L1 COUT GND GND CVCC2 RSENS : : : : RVC CVC VIN ISP 1 12 VCC2 ISN 2 11 VCC1 VC 3 10 SW ACTL 4 9 GND 5 8 SS 7 OVP DCTL EN 6 GND Grand Plane CVIN CVCC1 GND Locate input capacitor as close VCC as possible. CSS GND Locate the compensation components to VC pin as close as possible. Figure 7. PCB Layout Guide Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8450/B-05 August 2014 is a registered trademark of Richtek Technology Corporation. www.richtek.com 13 RT8450/B Outline Dimension D L U EXPOSED THERMAL PAD (Bottom of Package) E V E1 e A2 A A1 b Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 1.000 1.200 0.039 0.047 A1 0.000 0.150 0.000 0.006 A2 0.800 1.050 0.031 0.041 b 0.190 0.300 0.007 0.012 D 4.900 5.100 0.193 0.201 e 0.65 0.026 E 6.300 6.500 0.248 0.256 E1 4.300 4.500 0.169 0.177 L 0.450 0.750 0.018 0.030 U 2.000 3.000 0.079 0.118 V 2.000 3.000 0.079 0.118 16-Lead TSSOP (Exposed Pad) Plastic Package Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 14 is a registered trademark of Richtek Technology Corporation. DS8450/B-05 August 2014 RT8450/B 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 D2 Dimensions In Millimeters 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 2.950 3.050 0.116 0.120 Option1 2.300 2.650 0.091 0.104 Option2 1.970 2.070 0.078 0.081 2.950 3.050 0.116 0.120 Option1 1.400 1.750 0.055 0.069 Option2 1.160 1.260 0.046 0.050 E E2 Dimensions In Inches e L 0.450 0.350 0.018 0.450 0.014 0.018 W-Type 12L DFN 3x3 Package Richtek Technology Corporation 14F, No. 8, Tai Yuen 1st 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. DS8450/B-05 August 2014 www.richtek.com 15