RT8476AGSP

® RT8476A Two-Stage Hysteretic LED Driver Controller General Description Features The RT8476A is a two-stage controller with dual gate drivers consist of a Boost converter (first stage) and a Buck converter (second stage). The advantage of the twostage topology is highly compatible with ET (Electronic Transformer) in MR16 / AR111 lighting market field applications.  Two-Stage Topology (Boost + Buck)  Wide Input Voltage Range : 4.5V to 40V Adjustable Peak Input Current Control Adjustable Boost Output Voltage Independent Dual Stage Function Adjustable LED Current with ± 5% LED Current Accuracy Input Under-Voltage Lockout Detection Thermal Shutdown Protection SOP-8 (Exposed Pad) Package RoHS Compliant and Halogen Free The first stage is a Boost converter for constant voltage output with inductor peak current over-current protection. The second stage is a Buck converter for constant output current by typical constant peak current regulation.         The RT8476A is equipped with dual output gate drivers for external power MOSFETs, suitable for higher power applications. Ordering Information RT8476A The RT8476A is available in the SOP-8 (Exposed pad) package. Package Type SP : SOP-8 (Exposed Pad-Option 2) Lead Plating System G : Green (Halogen Free and Pb Free) Applications        Note : MR16 Lighting Signage and Decorative LED Lighting Architectural Lighting High Power LED Lighting Low Voltage Industrial Lighting Indicator and Emergency Lighting Automotive LED Lighting Richtek 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. Simplified Application Circuit L1 RSENSE D6 COUT D1 D2 VL AC 12V RT8476A VCC OVP R5 CIN VN M1 GATE1 D3 ISN CREG CS D4 R6 Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8476A-01 March 2014 R4 ACTL LED+ C3 M2 D7 C6 L2 LED- GATE2 GND is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT8476A Pin Configurations Marking Information (TOP VIEW) RT8476AGSP : Product Number RT8476A GSPYMDNN YMDNN : Date Code 8 GATE1 CS 2 OVP 3 ACTL 4 GND GATE2 7 CREG 6 VCC 5 ISN 9 SOP-8 (Exposed Pad) Functional Pin Description Pin No. Pin Name Pin Function 1 GATE1 Gate Driver Output for External MOSFET Switch in the First Stage. 2 CS Current Sense Input for External MOSFET Switch. 3 OVP Over-Voltage Protection Sense Input. 4 ACTL Analog/PWM Dimming Control Input. 5 ISN LED Current Sense Amplifier Negativ e Input. 6 VCC 7 CREG 8 GATE2 Supply Voltage Input. For good bypass, place a ceramic capacitor near the VCC pin. Internal Regulator Output. Place an 1F capacitor between the CREG and GND pins. Gate Driver Output for External MOSFET Switch in the Second Stage. 9 (Exposed Pad) GND Ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. Function Block Diagram ISN VCC ACTL ACTL Logic -130mV Regulator V + - VCC CREG UV OVP Core Logic EN1 CREG + EN1 - CS GATE2 EN2 EN2 V 240mV GATE1 GND Operation The VCC of the RT8476A is supplied from the first stage Boost output. The first stage is a constant output voltage Boost topology. The CS pin senses the peak inductor current for over-current protection. The peak inductor current level can be adjusted by the sense resistor between MOSFET Source and GND. Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 The second stage is a constant output current Buck topology. The current sense voltage threshold between the VCC and ISN pins is only 130mV to reduce power loss. is a registered trademark of Richtek Technology Corporation. DS8476A-01 March 2014 RT8476A Absolute Maximum Ratings          (Note 1) Supply Input Voltage, VCC to GND ----------------------------------------------------------------------------------- −0.3V to 45V ACTL, CS, GATE1, GATE2, CREG, OVP to GND ----------------------------------------------------------------- −0.3V to 6V VCC to ISN ----------------------------------------------------------------------------------------------------------------- −1V to 3V Power Dissipation, PD @ TA = 25°C SOP-8 (Exposed Pad) --------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) SOP-8 (Exposed Pad), θJA ---------------------------------------------------------------------------------------------SOP-8 (Exposed Pad), θJC --------------------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Model) ---------------------------------------------------------------------------------------------MM (Machine Model) ----------------------------------------------------------------------------------------------------- Recommended Operating Conditions    3.44W 29°C/W 2°C/W 150°C 260°C −65°C to 150°C 2kV 200V (Note 4) Supply Input Voltage, VCC ---------------------------------------------------------------------------------------------- 4.5V to 40V Junction Temperature Range -------------------------------------------------------------------------------------------- −40°C to 125°C Ambient Temperature Range -------------------------------------------------------------------------------------------- −40°C to 85°C Electrical Characteristics (VCC = 10V, No Load, CLOAD = 1nF, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Supply Voltage CREG UVLO_ ON VUVOL_ON CS/OVP = 0V 3.85 4.15 4.45 V CREG UVLO_ OFF VUVOL_OFF CS/OVP = 0V -- 4.1 -- V VCC Shutdown Current I SHDN Before Start-Up, VCC = 3.5V -- 10 -- A VCC Quiescent Current IQ After Start-Up, VCC = 5V, GATE1 and GATE2 Stand Still -- 1.5 -- mA Internal Reference Voltage VCREG -- 5 -- V -- 4.9 -- V Supply Current Internal Reference Voltage I CREG = 20mA Current Sense Comparator CS Threshold Voltage VCS 215 240 265 mV CS Pin Leakage Current I CS -- 1 -- A ACTL Turn On Threshold VACTL_ON -- 240 -- mV ACTL Turn Off Threshold VACTL_OFF -- 120 -- mV ACTL Clamp Voltage -- 2.5 -- V ACTL Input Bias Current -- -- 1 A Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8476A-01 March 2014 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT8476A Parameter Symbol Test Conditions Min Typ Max Unit OVP Threshold OVP High-Level VOVP_H 1.71 1.9 2.09 Low-Level VOVP_L 1.44 1.6 1.76 -- 1 -- A -- 1.5 -- s OVP Pin Leakage Current IOVP V Gate Driver GATE1 Duty Off-Time UGATE1 Drive Sink RUGATE1sk Sink = 50mA -- 2 --  LGATE1 Drive Source RLGATE1sr Source = 50mA -- 1.25 --  -- 90 -- k 123.5 130 136.5 mV GATE1 Default Pull Down Resistor Buck Converter ISN Threshold VISN ISN Hysteresis VISN 10 15 20 % ISN Pin Leakage Current IISN -- 1 -- A UGATE2 Drive Sink RUGATE2sk Sink = 50mA -- 2 --  LGATE2 Drive Source RLGATE2sr Source = 50mA -- 1.25 --  -- 90 -- k 140 155 170 C -- 35 -- C GATE2 Default Pull Down Resistor Temperature Protection Thermal Shutdown Threshold T SD Thermal Shutdown Hysteresis TSD Note 1. Stresses beyond those listed “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 may 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 measured at the exposed pad of the package. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 is a registered trademark of Richtek Technology Corporation. DS8476A-01 March 2014 RT8476A Typical Application Circuit L1 22µH D1 D2 VL AC 12V CIN 1µF VN D3 D4 RSENSE 280m D6 R4 RT8476A 3 6 OVP VCC R5 ISN 5 7 CREG M1 R6 120m 1 GATE1 C3 4.7µF 2 CS M2 4 8 ACTL GATE2 GND 9 (Exposed Pad) Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8476A-01 March 2014 COUT LED+ D7 L2 120µH C6 4.7µF LED- is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT8476A Typical Operating Characteristics Quiescent Current vs. Temperature 4.0 1.7 3.5 Quiescent Current (mA) Quiescent Current (mA) Quiescent Current vs. VCC 1.8 1.6 1.5 1.4 1.3 1.2 1.1 3.0 2.5 2.0 1.5 1.0 0.5 VCC = 4.5V to 30V, Gate Capacitor = 100pF VCC = 24V, Gate Capacitor = 100pF 1.0 0.0 4 9.2 14.4 19.6 24.8 -50 30 -25 0 VCC (V) Operating Current vs. VCC 75 100 125 Operating Current vs. Temperature 4.0 2.5 3.5 Operating Current (mA) Operating Current (mA) 50 Temperature (°C) 2.8 2.2 1.9 1.6 1.3 3.0 2.5 2.0 1.5 VCC = 4.5V to 30V, Gate Capacitor = 100pF VCC = 24V, Gate Capacitor = 100pF 1.0 1.0 4 9.2 14.4 19.6 24.8 30 -50 -25 0 VCC (V) 25 50 75 100 125 Temperature (°C) CREG Voltage vs. VCC CREG Voltage vs. Temperature 7 5.4 5.3 CREG Voltage (V) 6 CREG Voltage (V) 25 5 ICREG = 0mA ICREG = -20mA 4 3 5.2 5.1 ICREG = 0mA ICREG = -20mA 5.0 4.9 VCC = 10V VCC = 4.5V to 30V 2 4.8 4.5 9.6 14.7 19.8 24.9 VCC (V) Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 30 -50 -25 0 25 50 75 100 125 Temperature (°C) is a registered trademark of Richtek Technology Corporation. DS8476A-01 March 2014 RT8476A CS Threshold vs. Temperature 280 250 260 CS Threshold (mV) CS Threshold (mV) CS Threshold vs. VCC 260 240 230 220 240 220 200 210 180 4.5 9.6 14.7 19.8 24.9 30 -50 -25 0 50 75 150 140 140 ISN Threshold (V) 150 130 120 110 100 125 130 120 110 100 VCC = 30V VCC = 4.5V to 40V 90 90 4 8 12 16 20 24 28 32 36 40 -50 -25 0 25 50 75 100 125 Temperature (°C) VCC (V) OVP Hi/Low Level Voltage vs. Temperature OVP Hi/Low Level Voltage vs. VCC 2.1 2.2 2.0 High 1.9 1.8 1.7 Low 1.6 1.5 VCC = 4.5V to 30V OVP Hi/Low Level Voltage (V) OVP Hi/Low Level Voltage (V) 100 ISN Threshold vs. Temperature ISN Threshold vs. VCC ISN Threshold (mV) 25 Temperature (°C) VCC (V) 2.1 2.0 High 1.9 1.8 1.7 Low 1.6 1.5 1.4 VCC = 10V 1.3 1.4 4.5 9.6 14.7 19.8 24.9 VCC (V) Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8476A-01 March 2014 30 -50 -25 0 25 50 75 100 125 Temperature (°C) is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT8476A ACTL Threshold Voltage vs. VCC ACTL Threshold Voltage vs. Temperature 270 ACTL Threshold Voltage (mV) ACTL Threshold Voltage (mV) 270 On 236 202 168 134 Off 100 On 236 202 168 134 Off 100 4 9 14 19 24 29 -50 -25 0 VCC (V) 25 50 75 100 125 Temperature (°C) LED Current vs. ACTL Voltage LED Current vs. Input Voltage 800 450 IOUT = 756mA 440 600 LED Current (mA) LED Current (mA) 700 500 IOUT = 382mA 400 300 IOUT = 185mA 200 430 420 410 400 100 390 0 380 VCC = 4.5V to 20V, Load = 4LED 0 0.5 1 1.5 2 2.5 3 4.5 7.6 10.7 ACTL Voltage (V) LED Current vs. Output Voltage 16.9 20 GATE1 Duty Off-Time vs. Temperature 3.1 440 GATE1 Duty Off-Time (µs) 437 434 LED Current (mA) 13.8 Input Voltage (V) 431 428 425 422 419 416 413 2.8 2.5 2.2 1.9 1.6 1.3 VCC = 10V Load = 1LED to 6LED 1.0 410 4.5 7.6 10.7 13.8 16.9 Output Voltage (V) Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 20 -50 -25 0 25 50 75 100 125 Temperature (°C) is a registered trademark of Richtek Technology Corporation. DS8476A-01 March 2014 RT8476A GATE1 Rising/Falling Time vs. VCC Power On from VCC GATE1 Rising/Falling Time (ns) 60 55 IOUT (500mA/Div) 50 Rising 45 I IN (2A/Div) 40 35 Falling 30 25 VCC = 4.5V to 30V VOUT (10V/Div) V CC (20V/Div) VCC = 10V, 4LEDs 20 4.5 9.6 14.7 19.8 24.9 30 Time (5ms/Div) VCC (V) Power On from AC-IN Power Off from VCC IOUT (500mA/Div) IOUT (500mA/Div) I IN (2A/Div) VOUT (10V/Div) VOUT (10V/Div) V CC (20V/Div) V CC (20V/Div) AC-IN (50V/Div) VCC = 10V, 4LEDs Time (5ms/Div) AC = 12V, 4LEDs Time (5ms/Div) Power Off from AC-IN IOUT (500mA/Div) VOUT (10V/Div) V CC (20V/Div) AC-IN (50V/Div) AC = 12V, 4LEDs Time (10ms/Div) Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8476A-01 March 2014 is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT8476A Application Information The RT8476A consists of a constant output current Buck controller and a fixed off-time controlled Boost controller. The Boost controller is based on a peak current, fixed offtime control architecture and is designed to operate up to 800kHz to use a very small inductor for space constrained applications. A high-side current sense resistor is used to set the output current of the Buck controller. A 1% sense resistor performs a ±5% LED current accuracy for the best performance. Under-Voltage Lockout (UVLO) The RT8476A includes an under-voltage lookout function with 100mV hysteresis. The internal MOSFET turns off when VCC falls below 4.2V (typ.). CREG Regulator The CREG pin requires a capacitor for stable operation and to store the charge for the large GATE switching currents. Choose a 10V rated low ESR, X7R or X5R, ceramic capacitor for best performance. A 4.7μF capacitor will be adequate for many applications. Place the capacitor close to the IC to minimize the trace length to the CREG pin and to the IC ground. An internal current limit on the CREG output protects the RT8476A from excessive onchip power dissipation. The CREG pin has set the output to 4.3V (typ.) to protect the external FETs from excessive power dissipation caused by not being fully enhanced. If the CREG pin is used to drive extra circuits beside RT8476A, the extra loads should be limited to less than 10mA. Gate Driver There are two gate drivers, GATE1 and GATE2, in the RT8476A. The Gate driver consists of a CMOS buffer designed to drive the external power MOSFET. It features unbalanced source and sink capabilities to optimize switch on and off performance without additional external components. Whenever the IC supply voltage is lower than the under-voltage threshold, the Gate Driver is pulled low. Analog Dimming Control The ACTL terminal is driven by an external voltage, VACTL, to adjust the output current to an average value set by Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 RSENSE. The voltage range for VACTL to adjust the output current is from 0.24V to 2.5V. If VACTL becomes larger than 2.5V, the output current value will just be determined by the external/resistor, RSENSE. V  0.24 IOUT avg = 0.13V  ACTL RSENSE 2.5 ACTL Control The ACTL pin is the dimming function pin with the DC level proportional to the output LED current until ACTL clamp voltage that is the max output current (100%). Average Output Current Setting The output current that flows through the LED string is set by an external resistor, RSENSE, which is connected between the VCC and ISN terminal. The relationship between output current, IOUT, and RSENSE is shown as below : IOUT = 130mV RSENSE LED Current Ripple Reduction Higher LED current ripple will shorten the LED life time and increase heat accumulation of LED. To reduce the LED current ripple, an output capacitor in parallel with the LED should be added. The typical value of output capacitor is 4.7μF. VCC Voltage Setting The VCC voltage setting is equipped with an Over-Voltage Protection (OVP) function. When the voltage at the OVP pin exceeds threshold approximately 1.9V, the power switch is turned off. The power switch can be turned on again once the voltage at the OVP pin drops below 1.6V. For Boost applications, the output voltage can be set by the following equation : VCC(MAX) = 1.9 x (1 + R4 / R5) R4 and R5 are the voltage divider resistors from VOUT to GND with the divider center node connected to the OVP pin. For MR16 LED lamp application, the minimum voltage of VCC should maintain above 25V for stable operation. is a registered trademark of Richtek Technology Corporation. DS8476A-01 March 2014 RT8476A Step-Down Converter Inductor Selection The RT8476A implemented a simple high efficiency, continuous mode inductive step-down converter. The inductance L2 in Buck converter is determined by the following factors : inductor ripple current, switching frequency, VOUT/VIN ratio, internal MOSFET, topology specifications, and component parameter. The inductance L2 is calculated according to the following equation : L2 ≥ [VCC(MAX) − VOUT − VISN − (RDS2(ON) x IOUT)] x D / [fSW x ΔIOUT] where fsw is switching frequency (Hz). will pull low after fixed delay time 1.5μs (typ.) and then turn on again after OVP operation is removed. This cycle repeats, keeping the output voltage within a small window. Following the constant off-time mechanism, the inductance L1 is calculated according to the following equation : L1 > tOFF x (VCC(MAX) − VIN(MIN) + VF) / ILIM where tOFF is Off-Time. The typical value is 1.5μs. ILIM is the input current. The typical value is 2A for MR16 application. VCC is the supply input voltage (V) VIN is the input voltage after bridge diodes (V) RDS2(ON) is the low-side switch on-resistance of external MOSFET (M2). The typical value is 0.35Ω. VF is the forward voltage (V) D is the duty cycle = VOUT / VIN L1 is the inductance (H) IOUT is the required LED current (A) D = 1 − (VIN / VOUT) ΔIOUT is the inductor peak-peak ripple current (internally set to 0.3 x IOUT) fSW = (1 − D) / tOFF VCC is the supply input voltage (V) D is the operation duty VOUT is the total LED forward voltage (V) fSW is the switching frequency of Boost controller. VISN is the voltage cross current sense resistor (V) Check the ILIM setting satisfied the output LED current request by the following equation : L2 is the inductance (H) The selected inductor must have saturation current higher than the peak output LED current and continuous current rating above the required average output LED current. In general, the inductor saturation current should be 1.5 times the LED current. In order to minimize output current ripple, higher values of inductance are recommended at higher supply voltages. Because high values of inductance has high line resistance, it will cause lower efficiency. where (IOUT + ΔIOUT) < [2 x L1 x ILIM + tOFF x (VIN − VOUT − VF)] x VIN / [2 x L1 x (VCC)] Diode Selection To obtain better efficiency, the Schottky diode is recommended for its low reverse leakage current, low recovery time and low forward voltage. With its low power dissipation, the Schottky diode outperforms other silicon diodes and increases overall efficiency. Step-Up Converter Inductor Selection The RT8476A uses a constant off-time control to provide high efficiency step-up converter. The resistor, R6, between the Source of the external N-MOSFET and GND should be selected to provide adequate switch maximum current to drive the application. The current limit threshold on the CS pin of the RT8476A is 240mV (typ.). When the CS pin voltage is higher than the 240mV reference, the comparator will disable the power section. The GATE1 Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8476A-01 March 2014 Input Capacitor selection Input capacitor has to supply peak current to the inductor and flatten the current ripple on the input. The low ESR condition is required to avoid increasing power loss. The ceramic capacitor is recommended due to its excellent high frequency characteristic and low ESR, which are suitable for the RT8476A. For maximum stability over the entire operating temperature range, capacitors with better dielectric are suggested. is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT8476A Maximum Power Dissipation (W)1 Thermal Protection A thermal protection feature is to protect the RT8476A from excessive heat damage. When the junction temperature exceeds 150°C, the thermal protection will turn off the LX terminal. When the junction temperature drops below 125°C, the RT8476A will turn on the LX terminal and return to normal operation. 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 maximum power dissipation can be calculated by the following formula : 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. The maximum power dissipation depends on the operating ambient temperature for fixed T J(MAX) and thermal resistance, θJA. The derating curve in Figure 1 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation. Copyright © 2014 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 Four-Layer PCB 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 1. Derating Curve of Maximum Power Dissipation 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, D6, M1, CIN, and COUT must be placed as close to each other as possible to reduce the ac current loop area. The power components L2, D7, and M2 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.  The capacitor COUT, C6 and external resistor, RSENSE, must be placed as close as possible to the VCC and ISN pins of the device respectively.  The GND should be connected to a strong ground plane.  Keep the main current traces as short and wide as possible. 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) package, the thermal resistance, θJA, is 29°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 formula : P D(MAX) = (125°C − 25°C) / (29°C/W) = 3.44W for SOP-8 (Exposed Pad) package 4.0 is a registered trademark of Richtek Technology Corporation. DS8476A-01 March 2014 RT8476A D6 L1 VIN VCC R4 OVP R5 COUT RSENSE C15 D7 D1 D2 GATE1 VL VN R11 D3 D4 L2 CIN M1 R6 CS 2 OVP 3 ACTL 4 GND 8 GATE2 7 CREG 6 VCC 5 ISN 9 LED+ C6 GND L3 C8 LED- M2 C5 C3 GND Figure 2. PCB Layout Guide Copyright © 2014 Richtek Technology Corporation. All rights reserved. DS8476A-01 March 2014 is a registered trademark of Richtek Technology Corporation. www.richtek.com 13 RT8476A Outline Dimension H A M EXPOSED THERMAL PAD (Bottom of Package) Y J X B F C I D Dimensions In Millimeters Dimensions In Inches Symbol Min Max Min Max A 4.801 5.004 0.189 0.197 B 3.810 4.000 0.150 0.157 C 1.346 1.753 0.053 0.069 D 0.330 0.510 0.013 0.020 F 1.194 1.346 0.047 0.053 H 0.170 0.254 0.007 0.010 I 0.000 0.152 0.000 0.006 J 5.791 6.200 0.228 0.244 M 0.406 1.270 0.016 0.050 X 2.000 2.300 0.079 0.091 Y 2.000 2.300 0.079 0.091 X 2.100 2.500 0.083 0.098 Y 3.000 3.500 0.118 0.138 Option 1 Option 2 8-Lead SOP (Exposed Pad) Plastic 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. www.richtek.com 14 DS8476A-01 March 2014