RT4813 High Efficiency Boost Converter Features General Description The RT4813 allows systems to take advantage of new battery chemistries that can supply significant energy when the battery voltage is lower than the required voltage for system power ICs. By combining built-in power transistors, synchronous rectification, and low supply current; this IC provides a compact solution for systems using advanced Li-Ion battery chemistries. The RT4813 is a boost regulator designed to provide a minimum output voltage from a single-cell Li-Ion battery, even when the battery voltage is below system minimum. In boost mode, output voltage regulation is guaranteed to a maximum load current of 3.1A. Quiescent current in Shutdown Mode is less than 1A, which maximizes battery life. CMCOT Topology and Small Output Ripple when VIN Close VOUT Voltage Operates from a Single Li-ion Cell : 1.8V to 5.5V Adjustable Output Voltage : 1.8V to 5.5V PSM Operation Up to 96% Efficiency Input Over Current Limit Input / Output Over Voltage Protection Programmable Average Output Current Limit Range : 3100mA to 1225mA Internal Compensation Output Discharge Output Short Protection True Load Disconnect Applications Ordering Information RT4813 Package Type QUF : UQFN-9L 2x2 (FC) (U-Type) Single-Cell Li-Ion, LiFePO4 Smart-Phones Portable Equipment Marking Information 3V : Product Code W : Date Code Lead Plating System G : Green (Halogen Free and Pb Free) 3VW Note : 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 VIN RT4813 SW C1 R1 R2 SCL SDA DS4813-00 April 2016 EN EN GND Copyright © 2016 Richtek Technology Corporation. All rights reserved. C3 FB VIN C2 I2C Control VOUT VOUT R3 is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT4813 Pin Configurations SCL (TOP VIEW) 8 VIN 2 7 FB SW 3 6 GND PGND 4 5 SDA EN 1 VOUT 9 UQFN-9L 2x2 (FC) Functional Pin Description Pin No. Pin Name Pin Function 1 EN Enable Input (1 enabled, 0 disabled), Must Not be Left Floating. 2 VOUT Boost Converter Output. 3 SW Switching Node. 4 PGND Power Ground. 5 SDA I2C Interface Data Input. 6 GND Analog Ground. 7 FB Voltage Feedback. 8 VIN Power Input. Input capacitor CIN must be placed as close to IC as possible. 9 SCL I2C Interface Clock Input. Functional Block Diagram VOUT VIN SDA SCL OCP Gate DRV Digital CTRL PWM CTRL EN SW AMP - FB + OSC OTP PGND Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 UVLO VREF GND is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 RT4813 Operation RT4813 combined built-in power transistors, synchronous rectification, and low supply current, it provides a compact solution for system using advanced Li-Ion battery chemistries. In boost mode, output voltage regulation is guaranteed to a maximum load current of 3.1.A. Quiescent current in Shutdown mode is less than 1A, which maximizes battery life. Mode Startup and Shutdown State When VIN is rising and through the LIN state, it will enter the Startup state. If EN is pulled low, any function is turned-off in shutdown mode. Soft-Start State It starts to switch in Soft-start state. After the LIN state, output voltage is rising with the internal reference voltage. Depiction Condition LIN 1 Linear startup 1 VIN > VOUT Fault State LIN 2 Linear startup 2 VIN > VOUT Soft-Start Boost soft-start VOUT < VOUT(MIN) As the Figure 1 shown, it will enter to the Fault state as below, Boost Boost mode VOUT = VOUT(MIN) LIN The timeout of LIN2 is over the 1024s. It will be the high impedance between the input and LIN State When VIN is rising, it enters the LIN State. There are two parts for the LIN state. It provides maximum current for 1A to charge the COUT in LIN1, and the other one is for 2A in LIN2. By the way, the EN is pulled high and VIN > UVLO. As the figure shown, if the timeout is over the specification, it will enter the Fault mode. Timeout > 512μs Timeout < 1024μs Boost mode The converter senses the current signal when the high-side P-MOSFET turns on. As a result, the OCP is cycle by-cycle current limitation. If the OCP occurs, the converter holds off the next on pulse until inductor OTP LIN 1 Soft-Start OCP current drops below the OCP limit. EN = 1, Vin > UVLO Timeout < 512μs output when the fault is triggered. A restart will be start after 20ms. LIN 2 Timeout > 1024μs The converter has an over-temperature protection. When the junction temperature is higher than the thermal shutdown rising threshold, the system will be latched and the output voltage will no longer be regulated until the junction temperature drops under the falling threshold. Fault State Figure 1. RT4813 State Chart Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS4813-00 April 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT4813 Absolute Maximum Ratings (Note 1) VIN, VINA to GND----------------------------------------------------------------------------------------------------- 0.2V to 6V VOUT to GND ---------------------------------------------------------------------------------------------------------- 6V Power Dissipation, PD @ TA = 25C UQFN-9L 2x2 (FC) ---------------------------------------------------------------------------------------------------- 0.89W Package Thermal Resistance (Note 2) UQFN-9L 2x2 (FC), JA ---------------------------------------------------------------------------------------------- 111.5C/W UQFN-9L 2x2 (FC), JC---------------------------------------------------------------------------------------------- 19.6 C/W Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------- 260C Junction Temperature ------------------------------------------------------------------------------------------------ 150C Storage Temperature Range --------------------------------------------------------------------------------------- 65C to 150C ESD Susceptibility (Note 3) HBM (Human Body Model) ----------------------------------------------------------------------------------------- 2kV MM (Machine Model) ------------------------------------------------------------------------------------------------- 200V Recommended Operating Conditions (Note 4) Input Voltage Range -------------------------------------------------------------------------------------------------- 1.8V to 5.5V Output Voltage Range ----------------------------------------------------------------------------------------------- 1.8V to 5.5V Ambient Temperature Range--------------------------------------------------------------------------------------- 40C to 85C Junction Temperature Range -------------------------------------------------------------------------------------- 40C to 125C Electrical Characteristics (VIN = 3.6V, TA = 25C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit Under Voltage Lockout Rising Threshold VUVLOR 1.6 1.7 1.8 V Under Voltage Lockout Falling Threshold VUVLOF 1.5 1.6 1.7 V FB Voltage VFB CCM 0.495 0.5 0.505 V VOUT Voltage (I2C) VOUT CCM 1 0 1 % Shutdown Current ISHDN EN = 0V, -- 0.1 2 A Close loop, no load -- 120 -- A -- 1 -- A -- 0.5 -- MHz -- 6 -- A Quiescent Current Pre-Charge Current IPre Switching Frequency f SW Valley Current Limit IOC VOUT VIN > 1V, CCM High Side Switch RON VIN = VINA = 5V -- 43 55 m Low Side Switch RON VIN = VINA = 5V -- 26 35 m FB Pin Input Leakage IFB 1 -- 1 A Leakage of SW ISW -- -- 5 A Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 RT4813 Parameter Symbol Test Conditions CCM, VIN = 2.7V to 4.5V, VOUT = 5V, IOUT = 500mA CCM, IOUT < 3.1A, VIN = 3.6V, VOUT = 5V Min Typ Max Unit -- 0.5 -- % -- 0.5 -- % Line Regulation VOUT, LINE Load Regulation VOUT, LOAD Output Over Voltage Protection VOVP -- 6 -- V Low-Level VIL -- -- 0.4 V High-Level VIH 1.2 -- -- V -- 0.1 1 A TSD -- 160 C TSD -- 30 C EN Input Voltage EN Sink Current Thermal Shutdown Thermal Shutdown Hysteresis 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. JA is measured at TA = 25C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. JC is measured at the exposed pad of the package. Note 3. Devices are ESD sensitive. Handling precaution recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS4813-00 April 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT4813 Typical Application Circuit L1 VIN RT4813 3 SW VOUT C1 22μF x 2 8 VIN C2 1μF FB 2 7 R1 909k C3 22μF x 2 R2 100k VIN R4 10k R5 10k 2 I C control 9 5 EN SCL Copyright © 2016 Richtek Technology Corporation. All rights reserved. 1 EN R3 1M SDA GND 6 www.richtek.com 6 VOUT PGND 4 is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 RT4813 Typical Operating Characteristics Efficiency vs. Output Curent Output Voltage Ripple 100 90 VIN = 4.2V Efficiency (%) 80 VIN = 3.7V 70 VIN = 3.3V 60 VIN = 2.5V 50 LX (2V/Div) VIN = 1.8V 40 VOUT_ac (50mV/Div) 30 20 VOUT = 5V, L = 1.5μH (TDK SPM6530), 10 VIN = 2.5V, VOUT = 5V, IOUT = 0mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 COUT = 22μF x 2, Load = 1mA to 3A 0 0 500 1000 1500 2000 2500 3000 Time (10s/Div) Output Current (mA) Output Voltage Ripple Output Voltage Ripple LX (2V/Div) LX (2V/Div) VOUT_ac (50mV/Div) VOUT_ac (50mV/Div) VIN = 3.6V, VOUT = 5V, IOUT = 0mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 VIN = 4.2V, VOUT = 5V, IOUT = 0mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 Time (10s/Div) Time (10s/Div) Output Voltage Ripple Output Voltage Ripple VIN = 2.5V, VOUT = 5V, IOUT = 1000mA LX (2V/Div) VIN = 3.6V, VOUT = 5V, IOUT = 1000mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 LX (2V/Div) VOUT_ac (20mV/Div) VOUT_ac (20mV/Div) L = 1.5H (TDK SPM6530), COUT = 22F x 2 Time (1s/Div) Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS4813-00 April 2016 Time (1s/Div) is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT4813 Load Transient Response Output Voltage Ripple VIN = 4.2V, VOUT = 5V, IOUT = 1000mA L = 1.5H (TDK SPM6530), COUT = 22F x 2 LX (2V/Div) VIN = 2.5V, VOUT = 5V, IOUT = 1.5A to 3A L = 1.5H (TDK SPM6530), COUT = 22F x 2 IOUT (1A/Div) VOUT_ac (20mV/Div) VOUT_ac (500mV/Div) Slew rate = 100mA/μs Time (1s/Div) Time (250s/Div) Load Transient Response Load Transient Response VIN = 4.2V, VOUT = 5V, IOUT = 1.5A to 3A L = 1.5H (TDK SPM6530), COUT = 22F x 2 VIN = 3.7V, VOUT = 5V, IOUT = 1.5A to 3A L = 1.5H (TDK SPM6530), COUT = 22F x 2 IOUT (1A/Div) IOUT (1A/Div) VOUT_ac (500mV/Div) VOUT_ac (500mV/Diiv) Slew rate = 100mA/μs Slew rate = 100mA/μs Time (250s/Div) Time (250s/Div) Load Transient Response Load Transient Response VIN = 2.5V, VOUT = 5V, IOUT = 50mA to 150mA L = 1.5H, COUT = 22F x 2 VIN = 3.7V, VOUT = 5V, IOUT = 50mA to 150mA L = 1.5H, COUT = 22F x 2 IOUT (1A/Div) IOUT (1A/Div) VOUT_ac (500mV/Diiv) VOUT_ac (500mV/Diiv) Slew rate = 5mA/μs Time (250s/Div) Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 Slew rate = 5mA/μs Time (250s/Div) is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 RT4813 Load Transient Response VIN = 4.2V, VOUT = 5V, IOUT = 50mA to 150mA L = 1.5H, COUT = 22F x 2 IOUT (1A/Div) VOUT_ac (500mV/Diiv) Slew rate = 5mA/μs Time (250s/Div) Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS4813-00 April 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT4813 I2C Interface RT4813 I2C slave address = 0111001 (7 bits). I2C interface supports fast mode (bit rate up to 400kb/s). The write or read bit stream (N ≥ 1) is shown below : Read N bytes from RT4813 Slave Address Register Address S 0 A R/W Slave Address MSB A Sr 1 Data 2 A Data for Address = m LSB MSB Data N LSB A A Register Address S 0 A R/W MSB Data 1 LSB A Assume Address = m P Data for Address = m + N - 1 Data for Address = m + 1 Write N bytes to RT4813 Slave Address LSB A Assume Address = m MSB Data 1 MSB Data 2 LSB A Data for Address = m MSB A Data for Address = m + 1 Data N LSB A P Data for Address = m + N - 1 Driven by Master, Driven by Slave (RT4813), P Stop, S Start, Sr Repeat Start I2C Waveform Information SDA tLOW tF tSU,DAT tR tF tHD,STA tR tSP tBUF SCL tHD,STA S tHD,DAT tHIGH Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 tSU,STA tSU,STO Sr P S is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 RT4813 I2C Register Function Register Address Meaning Config 0X01 b[6] b[5] Reversed ILIM_OFF b[4] b[3] IPCHG b[2] b[0] (LSB) b[1] DRV_SEL<2:0> SSFM Default 0 0 0 1 1 1 1 0 Read/Write R/W R/W R/W R/W R/W R/W R/W R/W b[3] b[2] b[1] b[0] (LSB) ILIM_OFF IPCHG DRV_SEL<2:0> SSFM Function Register Address Charger 0X03 Control 3 b[7] (MSB) Meaning Default Read/Write ILIM_SS<7:4> Boost valley current limit setting 0 : Boost current limit enable (default) 1 : Boost current limit disable Pre-charge current setting. 00 : 0.5A 01 : 1A (default) 10 : 1.5A 11 : 2A LG driver driving capability 000 : Slowest : : 111 : Fastest (default) Spread spectrum setting. 0 : Spread spectrum disable (default) 1 : Spread spectrum enable b[7] (MSB) b[6] b[5] b[4] ILIM_SS<7:4> ILIM_AVG<3:0> 0 0 0 0 0 0 0 0 R/W R/W R/W R/W R/W R/W R/W R/W Soft-start period boost current limit setting. The default current is 1500mA. Code Current Code Current Code Current Code Current 1500mA 0000 0100 1500mA 1000 2500mA 1100 4500mA (default) 0001 1500mA 0101 1500mA 1001 3000mA 1101 5000mA 0010 1500mA 0110 1500mA 1010 3500mA 1110 5500mA 0011 1500mA 0111 2000mA 1011 4000mA 1111 6000mA Average Output Current limit setting. The default current is 3000mA. Code ILIM_AVG<3:0> Code Current Code Current Code Current 0100 2420mA 1000 1740mA 1100 1060mA 0001 Current 3100mA (Default) 2930mA 0101 2250mA 1001 1570mA 1101 890mA 0010 2760mA 0110 2080mA 1010 1400mA 1110 720mA 0011 2590mA 0111 1910mA 1011 1230mA 1111 550mA 0000 Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS4813-00 April 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT4813 Function Register Address Meaning OPTION 0X04 Default Read/Write FSW EN_IAVGCL EN_Discharge b[7] (MSB) b[6] b[4] b[3] Reversed Reversed Reversed Reversed 0 0 0 0 R/W R/W R/W R/W Boost frequency setting. 00 : 2MHz 01 : Do not allowed 10 : 1MHz 11 : 500kHz (default) Enable average output current limit 0 : Disable 1 : Enable (default) Enable discharge 0 : Disable 1 : Enable (default) Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 b[5] b[2] b[0] (LSB) b[1] EN EN _IAVGCL _Discharge FSW 1 1 1 1 R/W R/W R/W R/W is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 RT4813 Application Information Enable Power Save Mode The device can be enabled or disabled by the EN pin. When the EN pin is higher than the threshold of logic-high, the device starts operating with soft-start. Once the EN pin is set at low, the device will be shut down. In shutdown mode, the converter stops switching, internal control circuitry is turned off, and the load is disconnected from the input. This also means that the output voltage can drop below the input voltage during shutdown. PSM is the way to improve efficiency at light load. Soft-Start State After the successful completion of the LIN state (VOUT ≥ VIN 300mV), the regulator begins switching with boost valley-current limited value 3500mA. When the output voltage is lower than a set threshold voltage, the converter will operate in PSM. It raises the output voltage with several pulses until the loop exits PSM. Under-Voltage Lockout The under-voltage lockout circuit prevents the device from operating incorrectly at low input voltages. It prevents the converter from turning on the power switches under undefined conditions and prevents the battery from deep discharge. VIN voltage must be greater than 1.65V to enable the converter. During During Soft-Start state, VOUT is ramped up by Boost internal loop. If VOUT fails to reach target value during the Soft-Start period for more than 2ms, a fault condition is declared. operation, if VIN voltage drops below 1.55V, the converter is disabled until the supply exceeds the UVLO rising threshold. The RT4813 automatically restarts if the input voltage recovers to the input voltage UVLO high level. Output Voltage Setting Thermal Shutdown The output voltage is adjustable by an external resistive divider. The resistive divider must be connected between VOUT, FB and GND. When the output voltage is regulated properly, the typical value of the voltage at the FB pin is 500mV. Output voltage can be calculated by equation as below : The device has a built-in temperature sensor which monitors the internal junction temperature. If the V R1 R2 OUT 1 V FB designed to avoid unstable operation at IC temperatures near the over temperature threshold. temperature exceeds the threshold, the device stops operating. As soon as the IC temperature has decreased below the threshold with a hysteresis, it starts operating again. The built-in hysteresis is Inductor Selection The recommended nominal inductance value is 1.5H It is recommended to use inductor with dc saturation current ≥ 5000mA Table 1. List of Inductors Manufacturer Series Dimensions (in mm) Saturation Current (mA) TDK SPM6530T 7.1 x 6.5 x 3.0 11500 Taiyo Yuden NRS5040T 5.15 x 5.15 x 4.2 6400 Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS4813-00 April 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 13 RT4813 Input Capacitor Selection Output Discharge Function At least two capacitor and capacitance is 22F with rating voltage is 16V for DC bias input capacitor is recommended to improve transient behavior of the regulator and EMI behavior of the total power supply circuit for LX. And at least a 1F ceramic capacitor placed as close as possible to the VIN and GND pins With the EN pin set to low, the VOUT pin is internally connected to GND for 10ms by an internal discharge N-MOSFET switch. After the 10ms, IC will be true-shut down. of the IC is recommended. proper power up of the system. Output Capacitor Selection Valley Current Limit At least 22F x 2 capacitors is recommended to improve VOUT ripple. RT4813 employs a valley-current limit detection scheme to sense inductor current during the off-time. When the loading current is increased such that the loading is above the valley current limit threshold, the off-time is increased until the current is decreased to valley-current threshold. Next on-time begins after current is decreased to valley-current threshold. On-time is decided by (VOUT VIN) / VOUT ratio. The Output voltage ripple is inversely proportional to COUT. Output capacitor is selected according to output ripple which is calculated as : VRIPPLE(P P) tON ILOAD COUT This feature prevents residual charge voltages on capacitor connected to VOUT pins, which may impact output voltage decreases when further loading current increase. The current limit function is and V tON tSW D tSW 1 IN V OUT therefore : implemented by the scheme, refer to Figure 2. V COUT tSW 1 IN V OUT and RT4813 features the average output current limit to protect the output terminal. When the load current is over the limit, output current will be clamped. tSW Average Output Current Limit ILOAD V RIPPLE(P P) 1 fSW The maximum VRIPPLE occurs at minimum input voltage and maximum output load. IIN (DC) Valley Current Limit f Inductor Current IL IL = IIN (DC) VIN D L f Figure 2. Inductor Currents In Current Limit Operation Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 14 is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016 RT4813 Thermal Considerations Layout Consideration For continuous operation, do not exceed absolute maximum junction temperature. The maximum power The PCB layout is an important step to maintain the 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) / JA high performance of RT4813. Both the high current and the fast switching nodes demand full attention to the PCB layout to save the robustness of the RT4813 through the PCB layout. Improper layout might show the symptoms of poor line or load regulation, ground and output voltage shifts, where TJ(MAX) is the maximum junction temperature, TA is the ambient temperature, and JA is the junction to ambient thermal resistance. stability issues, unsatisfying EMI behavior or worsened efficiency. For the best performance of the RT4813, the following PCB layout guidelines must be strictly followed. For recommended operating condition specifications, dependent. For UQFN-9L 2x2 (FC) package, the thermal resistance, JA, is 111.5C/W on a standard JEDEC 51-7 four-layer thermal test board. The maximum power dissipation at TA = 25C can be calculated by the following formula : Input/Output capacitors must be placed as close as possible to the Input/Output pins. SW should be connected to Inductor by wide and short trace, keep sensitive components away from this trace. The feedback divider should be placed as close as possible to the FB pin. PD(MAX) = (125C 25C) / (111.5C/W) = 0.89W for UQFN-9L 2x2 (FC) package thermal resistance, JA. The derating curve in Figure 3 allows the designer to see the effect of rising ambient GND GND Cin The maximum power dissipation depends on the operating ambient temperature for fixed TJ(MAX) and temperature on the maximum power dissipation. Cout Maximum Power Dissipation (W)1 1.0 L Four-Layer PCB 0.9 Cout 0.8 Vout 0.7 Cin the maximum junction temperature is 125C. The junction to ambient thermal resistance, JA, is layout Vin 0.6 0.5 Figure 4. PCB Layout Guide 0.4 0.3 0.2 0.1 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 3. Derating Curve of Maximum Power Dissipation Copyright © 2016 Richtek Technology Corporation. All rights reserved. DS4813-00 April 2016 is a registered trademark of Richtek Technology Corporation. www.richtek.com 15 RT4813 Outline Dimension Symbol Dimensions In Millimeters Dimensions In Inches Min. Max. Min. Max. A 0.500 0.600 0.020 0.024 A1 0.000 0.050 0.000 0.002 A3 0.100 0.175 0.004 0.007 b 0.130 0.230 0.005 0.009 b1 0.200 0.300 0.008 0.012 D 1.950 2.050 0.077 0.081 E 1.950 2.050 0.077 0.081 e 0.500 0.020 L 0.350 0.450 0.014 0.018 L1 1.250 1.350 0.049 0.053 U-Type 9L QFN 2x2 (FC) 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. Copyright © 2016 Richtek Technology Corporation. All rights reserved. www.richtek.com 16 is a registered trademark of Richtek Technology Corporation. DS4813-00 April 2016