® RT5715 2A, 5.5V, Low IQ ACOT Synchronous Step-Down Converter General Description Features The RT5715 is a full featured 5.5V, 2A, Advanced ConstantOn-Time (ACOT) synchronous step-down converter with two integrated MOSFETs. The advanced COT operation allows transient responses to be optimized over a wide range of loads, and output capacitors to efficiently reduce external component count. The RT5715 provides up to 2.7MHz switching frequency to minimize the size of output inductor and capacitors. The RT5715 is available in the WDFN-8SL 2x2 package. 2.5V to 5.5V Input Voltage Range Advanced COT Control loop design Fast Transient Response Internal 100mΩ Ω and 80mΩ Ω Synchronous Rectifier Highly Accurate VOUT Regulation Over Load/Line Range Robust Loop Stability with Low-ESR COUT Ordering Information RT5715 Applications Package Type QW : WDFN-8SL 2x2 (W-Type) (Exposed Pad-Option 2) Mobile Phones and Handheld Devices STB, Cable Modem, and xDSL Platforms WLAN ASIC Power / Storage (SSD and HDD) General Purpose for POL LV Buck Converter Lead Plating System G : Green (Halogen Free and Pb Free) Note : Richtek products are : Pin Configurations (TOP VIEW) RoHS compliant and compatible with the current require- PGND ments of IPC/JEDEC J-STD-020. EN PGND AGND FB 1 2 3 4 9 8 7 6 5 VIN LX PGOOD VOS Suitable for use in SnPb or Pb-free soldering processes. Marking Information WDFN-8SL 2x2 3Z : Product Code 3ZW W : Date Code Simplified Application Circuit RT5715 VIN VIN Power Good PGOOD EN VOUT LX PGND AGND VOS FB R1 R2 Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS5715-00 March 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT5715 Functional Pin Description Pin No. Pin Name 1 EN 2, PGND 9 (Exposed Pad) Pin Function Enable Control Input. Pull High to Enable. Power Ground. The exposed pad must be soldered to a large PCB and connected to PGND for maximum power dissipation. 3 AGND Analog Ground. Should be electrically connected to GND close to the device. 4 FB Feedback Voltage Input. 5 VOS Output Voltage Sense Pin for the Internal Control Loop. Must be connected to output. 6 PGOOD Power Good Open-Drain Output. This pin is pulled to low if the output voltage is below regulation limits. Can be left floating if not used. 7 LX Switch Node. The Source of the internal high-side power MOSFET, and Drain of the internal low-side (synchronous) rectifier MOSFET. 8 VIN Power Input Supply Voltage, 2.5V to 5.5V. Function Block Diagram VOS EN AGND UVLO Shutdown Control OTP FB TON Error Amplifier + + Comparator + - VREF Logic Control Ramp Generator Current Limit Detector LX AZC LX VIN Driver LX LX PGOOD + VFB - Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 LX PGND is a registered trademark of Richtek Technology Corporation. DS5715-00 March 2016 RT5715 Operation The RT5715 is a low voltage synchronous step-down converter that can support input voltage ranging from 2.5V to 5.5V and the output current can be up to 2A. The RT5715 uses ACOTTM mode control. To achieve good stability with low-ESR ceramic capacitors, the ACOT uses a virtual inductor current ramp generated inside the IC. This internal ramp signal replaces the ESR ramp normally provided by the output capacitor's ESR. The ramp signal and other internal compensations are optimized for lowESR ceramic output capacitors. In steady-state operation, the feedback voltage, with the virtual inductor current ramp added, is compared to the reference voltage. When the combined signal is less than the reference, the on-time one-shot is triggered, as long as the minimum off-time one-shot is clear and the measured inductor current (through the synchronous rectifier) is below the current limit. The on-time one-shot turns on the high-side switch and the inductor current ramps up linearly. After the on-time, the high-side switch is turned off and the synchronous rectifier is turned on and the inductor current ramps down linearly. At the same time, the minimum off-time one-shot is triggered to prevent another immediate on-time during the noisy switching time and allow the feedback voltage and current sense signals to settle. The minimum off-time is kept short so that rapidly-repeated on-times can raise the inductor current quickly when needed. PWM Frequency and Adaptive On-Time Control Power Good When the output voltage is higher than PGOOD rising threshold, the PGOOD flag is high. Output Under-Voltage Protection (UVP) When the output voltage is lower than 66% reference voltage after soft-start, the UVP is triggered. Over-Current Protection (OCP) The RT5715 senses the current signal when the highside and low-side MOSFET turns on. As a result, The OCP is a cycle-by-cycle current limit. If an over-current condition occurs, the converter turns off the next on pulse until inductor current drops below the OCP limit. If the OCP is continually activated and the load current is larger than the current provided by the converter, the output voltage drops. Also, when the output voltage triggers the UVP also, the current will drop to ZC and trigger the resoft start sequence. Soft-Start An internal current source charges an internal capacitor to build the soft-start ramp voltage. The typical soft-start time is 150μs. Over-Temperature Protection (OTP) The RT5715 has an over-temperature protection. When the device triggers the OTP, the device shuts down until the temperature is back to normal. The on-time can be roughly estimated by the equation : V 1 TON = OUT where fOSC is nominal 2.7MHz VIN fOSC Under-Voltage Protection (UVLO) The UVLO continuously monitors the VCC voltage to make sure the device works properly. When the VCC is high enough to reach the UVLO high threshold voltage, the step-down converter softly starts or pre-bias to its regulated output voltage. When the VCC decreases to its low threshold voltage, the device shuts down. Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS5715-00 March 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT5715 Absolute Maximum Ratings (Note 1) Supply Input Voltage, VIN ----------------------------------------------------------------------------------------Other Pins ------------------------------------------------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C WDFN-8SL 2x2 -----------------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) WDFN-8SL 2x2, θJA ------------------------------------------------------------------------------------------------WDFN-8SL 2x2, θJC -----------------------------------------------------------------------------------------------Junction Temperature ----------------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Model) ---------------------------------------------------------------------------------------- Recommended Operating Conditions −0.3V to 6V −0.3V to (VIN + 0.3V) 1.538W 65°C/W 8°C/W 150°C 260°C −65°C to 150°C 2kV (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, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit 2.28 2.35 2.48 V -- 400 -- mV Under-Voltage Lockout Threshold VUVLO Under-Voltage Lockout Hysteresis VUVLOHY Shutdown Supply Current ISHDN EN = 0V -- -- 1 A Quiescent Current IQ Active, VFB = 0.5V, No Switching -- 30 -- A Voltage Reference VREF 0.4455 0.45 0.4545 V Peak Current 2.5 3.2 4 Valley Current 2 2.4 2.9 15 10 5 % Current Limit High-Side Low-Side ILIM VCC Rising A Power Good Threshold VPGTH VOUT Falling Referenced to VOUT Nominal Power Good Hysteresis VPGHY Hysteresis Referenced to VOUT Nominal -- 5 -- % Power Good Leakage Current IPG VPG = 5V -- 0.01 0.1 A Power Good Low Level Voltage VPGL Isink = 500A -- -- 0.3 V Enable Rising Threshold VENR Rising 1 -- -- V Enable Falling Threshold VENF Falling -- -- 0.4 V Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 is a registered trademark of Richtek Technology Corporation. DS5715-00 March 2016 RT5715 Parameter Symbol Test Conditions Min Typ Max Unit High-Side RP-MOSFET -- 100 -- Low-Side RN-MOSFET -- 80 -- Thermal Shutdown Temperature -- 150 -- C Thermal Shutdown Hysteresis -- 20 -- C -- 2.7 -- MHz -- 1 -- k Switch On-Resistance Switching Frequency fOSC Output Discharge Resistor m 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. The copper area is 70mm2 connected with IC exposed pad. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS5715-00 March 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT5715 Typical Application Circuit RT5715 8 VIN 10µF VIN PGOOD 1 EN LX 2, 9 (Exposed Pad) 6 7 5 PGND 3 AGND VOS FB 4 Power Good 180k L VOUT R1 COUT R2 Table 1. Suggested Component Values VOUT (V) R1 (k) R2 (k) L (H) COUT (F) 1.2V 65.3 39.2 0.47 22 1.8V 117.6 39.2 1 22 2.5V 178.6 39.2 1 22 3.3V 248.3 39.2 1 22 Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 is a registered trademark of Richtek Technology Corporation. DS5715-00 March 2016 RT5715 Typical Operating Characteristics Efficiency vs. Output Current Efficiency vs. Output Current 100 100 90 90 80 80 VIN = 3.3V VIN = 5V 60 Efficiency (%) Efficiency (%) 70 50 40 30 70 VIN = 3.3V VIN = 5V 60 50 40 30 20 20 10 10 VOUT = 1.2V, L = 0.47μH 0 0.001 VOUT = 1.2V, L = 0.47μH 0 0.01 0.1 1 0 10 0.5 Efficiency vs. Output Current 2 Efficiency vs. Output Current 100 100 90 90 VIN = 3.3V VIN = 5V 80 VIN = 3.3V VIN = 5V 80 Efficiency (%) 70 Efficiency (%) 1.5 Output Current (A) Output Current (A) 60 50 40 30 20 70 60 50 40 30 20 10 10 VOUT = 2.5V, L = 1μH 0 0.001 VOUT = 2.5V, L = 1μH 0 0.01 0.1 1 10 0 0.5 Output Current (A) 1.240 2.58 1.230 2.56 Output Voltage (V) 2.60 1.220 VIN = 5V VIN = 3.3V 1.200 1.5 2 Output Voltage vs. Output Current 1.250 1.210 1 Output Current (A) Output Voltage vs. Output Current Output Voltage(V) 1 1.190 1.180 1.170 2.54 VIN = 5V VIN = 3.3V 2.52 2.50 2.48 2.46 2.44 1.160 2.42 VOUT = 1.2V, L = 0.47μH 1.150 VOUT = 2.5V, L = 1μH 2.40 0 0.5 1 1.5 Output Current (A) Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS5715-00 March 2016 2 0 0.5 1 1.5 2 Output Current (A) is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT5715 Output Voltage vs. Input Voltage 2.54 1.215 2.53 2.52 1.210 Output Voltage (V) Output Voltage (V) Output Voltage vs. Input Voltage 1.220 1.205 1.200 1.195 1.190 2.51 2.50 2.49 2.48 2.47 2.46 1.185 2.45 VOUT = 1.2V, IOUT = 0A, L = 0.47μH 1.180 VOUT = 2.5V, IOUT = 0A, L = 1μH 2.44 2.5 3 3.5 4 4.5 5 5.5 2.5 3 3.5 Input Voltage (V) 5 5.5 Switching Frequency vs. Temperature 3.0 2.9 2.9 Switching Frequency (MHz)1 Switching Frequency (MHz)1 Switching Frequency vs. Input Voltage 2.8 2.7 2.6 2.5 2.4 2.3 2.2 VOUT = 1.2V, IOUT = 0A, L = 0.47μH 2.0 2.8 2.7 2.6 2.5 2.4 2.3 2.2 2.1 VIN = 5V, VOUT = 1.2V, IOUT = 1A, L = 0.47μH 2.0 2.5 3 3.5 4 4.5 5 5.5 -50 -25 0 Input Voltage (V) 50 75 100 125 Output Current Limit vs. Temperature 4.0 3.8 3.8 Output Current Limit (A) 4.0 3.6 3.4 3.2 3.0 2.8 2.6 2.4 2.2 25 Temperature (°C) Output Current Limit vs. Input Voltage Output Current Limit (A) 4.5 Input Voltage (V) 3.0 2.1 4 VOUT = 1.2V, L = 0.47μH 2.0 3.6 3.4 3.2 3.0 2.8 2.6 2.4 2.2 VIN = 3.3V, VOUT = 1.2V, L = 0.47μH 2.0 2.5 3 3.5 4 4.5 5 Input Voltage (V) Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 5.5 -50 -25 0 25 50 75 100 125 Temperature (°C) is a registered trademark of Richtek Technology Corporation. DS5715-00 March 2016 RT5715 Input Voltage vs. Temperature Enable Threshold vs. Temperature 2.5 2.0 2.4 1.8 UVLO Turn On 1.6 Enable Voltage (V) Input Voltage (V) 2.3 2.2 2.1 2.0 1.9 UVLO Turn Off 1.8 1.4 1.2 0.8 Enable Off 0.6 1.7 0.4 1.6 0.2 1.5 Enable On 1.0 0.0 -50 -25 0 25 50 75 100 125 -50 -25 0 25 50 75 100 Temperature (°C) Temperature (°C) Load Transient Response Load Transient Response VOUT (20mV/Div) VOUT (20mV/Div) IOUT (1A/Div) IOUT (1A/Div) VIN = 5V, VOUT = 2.5V, IOUT = 1A to 2A, L = 1μH VIN = 5V, VOUT = 2.5V, IOUT = 0A to 2A, L = 1μH Time (50μs/Div) Time (50μs/Div) Load Transient Response Load Transient Response VOUT (20mV/Div) VOUT (20mV/Div) IOUT (1A/Div) IOUT (1A/Div) VIN = 3.3V, VOUT = 1.2V, IOUT = 1A to 2A, L = 0.47μH Time (50μs/Div) Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS5715-00 March 2016 125 VIN = 3.3V, VOUT = 1.2V, IOUT = 0A to 2A, L = 0.47μH Time (50μs/Div) is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT5715 Voltage Ripple Voltage Ripple VOUT (20mV/Div) VOUT (20mV/Div) VLX (5V/Div) VLX (5V/Div) VIN = 3.3V, VOUT = 1.2V, IOUT = 2A, L = 0.47μH VIN = 3.3V, VOUT = 1.2V, IOUT = 1A, L = 0.47μH Time (500ns/Div) Time (500ns/Div) Voltage Ripple Voltage Ripple VOUT (20mV/Div) VOUT (20mV/Div) VLX (5V/Div) VLX (5V/Div) VIN = 5V, VOUT = 2.5V, IOUT = 2A, L = 1μH VIN = 5V, VOUT = 2.5V, IOUT = 1A, L = 1μH Time (500ns/Div) Time (500ns/Div) Power On from VIN Power Off from VIN VEN (5V/Div) VEN (5V/Div) VOUT (1V/Div) VLX (5V/Div) VOUT (1V/Div) VLX (5V/Div) IOUT (2A/Div) IOUT (2A/Div) VIN = 5V, VOUT = 1.2V, IOUT = 2A Time (100μs/Div) Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 VIN = 5V, VOUT = 1.2V, IOUT = 2A Time (100μs/Div) is a registered trademark of Richtek Technology Corporation. DS5715-00 March 2016 RT5715 Application Information The RT5715 is a single-phase step-down converter. Advance Constant-on-Time (ACOT) with fast transient response. An internal 0.45V reference allows the output voltage to be precisely regulated for low output voltage applications. A fixed switching frequency (2.7MHz) oscillator and internal compensation are integrated to minimize external component count. Protection features include over current protection, under voltage protection and over temperature protection. Output Voltage Setting The output voltage is set by an external resistive divider according to the following equation : R1 VOUT VREF x (1 ) R2 where VREF equals to 0.45V typical. The resistive divider allows the FB pin to sense a fraction of the output voltage as shown in Figure 1. VOUT R1 FB RT5715 R2 retry automatically. When the UVP condition is removed, the converter will resume operation. The UVP is disabled during soft-start period. Post Short VIN (2V/Div) VOUT (500mV/Div) SW (5V/Div) IOUT (2A/Div) VIN = 5V, VOUT = 1.2V, L = 1μH Time (1ms/Div) 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 : GND IRMS IOUT(MAX) Figure 1. Setting the Output Voltage Low Supply Operation The RT5715 is designed to operate down to an input supply voltage of 2.5V. One important consideration at low input supply voltages is that the RDS(ON) of the P-Channel and N-Channel power switches increases. The user should calculate the power dissipation when the RT5715 is used at 100% duty cycle with low input voltages to ensure that thermal limits are not exceeded. Under Voltage Protection (UVP) Hiccup Mode For the RT5715, it provides Hiccup Mode Under Voltage Protection (UVP). When the output voltage is lower than 66% reference voltage after soft-start, the UVP is triggered. If the UVP condition remains for a period, the RT5715 will Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS5715-00 March 2016 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 result in much difference. 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. The output ripple, ΔVOUT, is determined by : 1 VOUT IL ESR 8fCOUT is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT5715 The high Q of ceramic capacitors with trace inductance can also lead to significant ringing. Using Ceramic Input and Output Capacitors Higher value, 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. Table 2. Capacitors for CIN and COUT Component Supplier Part No. Capacitance Case (F) Size MuRata GRM31CR71A106KA01 10F 1206 MuRata GRM31CR71A226KA01 22F 1206 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. For recommended operating condition specifications, the maximum junction temperature is 125°C. The junction to ambient thermal resistance, θJA, is layout dependent. The junction to ambient thermal resistance, θJA, is layout dependent. For WDFN-8SL 2x2 packages, the thermal resistance, θJA, is 65°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 : PD(MAX) = (125°C − 25°C) / (65°C/W) = 1.538W for WDFN-8SL 2x2 package The maximum power dissipation depends on the operating ambient temperature for fixed T J(MAX) and thermal resistance, θJA. The derating curve in Figure 2 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation. 2.0 Maximum Power Dissipation (W)1 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 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. Four-Layer PCB 1.6 1.2 0.8 0.4 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 2. Derating Curve of Maximum Power Dissipation Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 is a registered trademark of Richtek Technology Corporation. DS5715-00 March 2016 RT5715 Layout Considerations Flood all unused areas on all layers with copper. Flooding Follow the PCB layout guidelines for optimal performance of the RT5715. with copper will reduce the temperature rise of power components. Connect the copper areas to any DC net (VIN, VOUT, GND, or any other DC rail in the system). Connect the terminal of the input capacitor(s), CIN, as close as possible to the VIN pin. This capacitor provides the AC current into the internal power MOSFETs. LX node experiences high frequency voltage swing and 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. Input capacitor must be placed as close to the IC as possible. GND CIN VIN LX should be connected to inductor by wide and short trace. Keep sensitive components away from this trace R2 EN PGND AGND FB 1 2 3 4 PGND CIN 9 8 7 6 5 VIN LX PGOOD VOS COUT L R1 COUT VOUT VOUT The feedback and must be connected as close to the device as possible. Keep sensitive component away. Figure 3. PCB Layout Guide Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS5715-00 March 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 13 RT5715 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 0.200 0.300 0.008 0.012 D 1.900 2.100 0.075 0.083 Option1 1.150 1.250 0.045 0.049 Option2 1.550 1.650 0.061 0.065 E 1.900 2.100 0.075 0.083 Option1 0.750 0.850 0.030 0.033 Option2 0.850 0.950 0.033 0.037 D2 E2 e L 0.500 0.250 0.020 0.350 0.010 0.014 W-Type 8SL DFN 2x2 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 DS5715-00 March 2016