RT5707WSC

® RT5707/A Ultra-Low Quiescent Current HCOT Buck Converter General Description Features The RT5707/A is a high efficiency synchronous step-down converter featuring typ. 360nA quiescent current. It provides  Input Voltage Range : 2.2V to 5.5V  Programmable Output Voltage 8-Level  RT5707 1.2V to 3.3V  RT5707A 0.7V to 3.1V Typ. 360nA Quiescent Current PSM Operation Up to 94% Efficiency Internal Compensation Output Voltage Discharge Over-Current Protection Over-Temperature Protection Output Current  RT5707 600mA, Peak to 1A  RT5707A 400mA, Peak to 0.5A Automatic Transition to 100% Duty Cycle Operation high efficiency at light load down to 10mA. Its input voltage range is from 2.2V to 5.5V. The RT5707 provides eight programmable output voltage 1.2V to 3.3V while delivering output current up to 600mA, peak to 1A. The RT5707A provides eight programmable output voltage 0.7V to 3.1V while delivering output current up to 400mA, peak to 0.5A.      The Hysteretic Constant-On-Time (HCOT) operation with internal compensation allow the transient response to be optimized over a wide range of loads and output capacitors.    The RT5707/A is a available in WL-CSP-8B 0.9x1.6 (BSC) package.  Ordering Information Applications RT5707/A  Package Type WSC : WL-CSP-8B 0.9x1.6 (BSC)   Note :  Richtek products are :   RoHS compliant and compatible with the current require-  Hand-Held Devices Portable Information Battery Powered Equipment Wearable Devices Internet of Things Smart Watch ments of IPC/JEDEC J-STD-020.  Suitable for use in SnPb or Pb-free soldering processes. Simplified Application Circuit RT5707/A VIN CIN VIN L1 SW VOUT COUT VOUT EN VSEL1 VIN or GND VSEL2 VIN or GND VESL3 VIN or GND GND Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS5707/A-04 September 2020 is a registered trademark of Richtek Technology Corporation. www.richtek.com 1 RT5707/A Marking Information RT5707WSC RT5707AWSC 6E : Product Code 6Z : Product Code W : Date Code 6EW W : Date Code 6ZW Pin Configuration (TOP VIEW) SW A1 A2 VIN EN B1 B2 GND VSEL1 C1 C2 VOUT VSEL2 D1 D2 VSEL3 WL-CSP-8B 0.9x1.6 (BSC) Functional Pin Description Pin No. Pin Name Pin Function A1 SW This pin is the connection between two build-in switches in the chip, which should be connected to the external inductor. The inductor should be connected to this pin with the shortest path. A2 VIN Supply input. A minimum of 10F (RT5707) and 4.7F (RT5707A) ceramic capacitor should be connected to this pin with the shortest path B1 EN Chip enable input pin. High level voltage enables the device while low level voltage turns the device off. This pin must be terminated. B2 GND Device ground pin. This pin should be connected to input and output capacitors with the shortest path. C1 VSEL1 Output voltage selection pin. This pin must be terminated. C2 VOUT Output voltage feedback pin. This pin should be connected close to the output capacitor terminal for better voltage regulation. A minimum of 10F ceramic capacitor should be connected to this pin with the shortest path. D1 VSEL2 Output voltage selection pin. This pin must be terminated. D2 VSEL3 Output voltage selection pin. This pin must be terminated. Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 2 is a registered trademark of Richtek Technology Corporation. DS5707/A-04 September 2020 RT5707/A Functional Block Diagram OSC OTP Soft-start EN VSEL1 Digital Control VSEL2 OCP VSEL3 UVLO VIN Gate Drive SW Fast Discharge EN VOUT R2 R1 FB VREF + AMP VREF GND PSM/PWM Control VOUT Operation The RT5707/A is a hysteretic constant on time (HCOT) switching buck converter. The RT5707/A provides OverTemperature Protection (OTP) and Over-Current Protection (OCP) mechanisms to prevent the device from damage with abnormal operations. When the EN voltage is logic low, the IC will be shut down with low input supply current less than 1μA. Enable The device can be enabled or disabled by the EN pin. When the EN pin is higher than the threshold of logic-high IC goes to normal operation. EN pin High transfer Low into shutdown mode, the converter stops switching, internal control circuitry is turned off and trigger discharge function. That discharge function will close after count 10ms (typ.). If systems need EN toggle operation that EN turn off time must larger than 100μs for internal circuit reset time. Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS5707/A-04 September 2020 UVLO Protection To protect the chip from operating at insufficient supply voltage, the UVLO is needed. When the input voltage is lower than the UVLO falling threshold voltage, the device will be lockout. 100% Duty Cycle Operation The converter enters 100% duty cycle operation once the input voltage decrease and the difference voltage between input and output is lower than VTH_100-. The output voltage follows the input voltage minus the voltage drop across the internal P_MOSFET and the inductor. Once the input voltage increases and trips the 100% mode exit threshold, VTH_100+, the converter backs to normal switching again. See Figure 1. is a registered trademark of Richtek Technology Corporation. www.richtek.com 3 RT5707/A VIN 100% duty cycle 100% duty cycle Over-Current Protection VOUT The OCP function is implemented by UGATE and LGATE. When the inductor current reaches the UGATE current limit threshold, the high-side MOSFET will be turned-off. The low-side MOSFET turns on to discharge the inductor current until the inductor current trips below the LGATE current limit threshold. After UGATE current limit triggered, the max inductor current is decided by the inductor current rising rate and the response delay time of the internal network. VIN VTH_100+ VTH_100VOUT_target VOUT VO tracks VIN Step Down Operation VO tracks VIN VUVLO+ VUVLO- During OCP period, the output voltage drops below the setting threshold (typ. 0.4V) and the current limit value is reduced for lowering the devices loss, reducing the heat and preventing further damage of the chip. Soft-start Figure 1. Automatic Transition into 100% Duty Cycle Over-Temperature Protection When the junction temperature exceeds the OTP threshold value, the IC will shut down the switching operation. Once the junction temperature cools down and is lower than the OTP lower threshold, the converter will automatically resume switching. Output Voltage Selection The RT5707/A provides 8 level output voltages which can be programmed via the volatage select pin VSEL1 to VSEL3. Table 1 indicates the setting to indivdual output voltage. Table 1. Output Voltage Setting Device RT5707 RT5707A VOUT (V) VSEL3 VSEL2 VSEL1 1.2 0 0 0 1.5 0 0 1 1.8 0 1 0 2.1* 0 1 1 2.5 1 0 0 2.8 1 0 1 3 1 1 0 3.3* 1 1 1 0.7 0 0 0 1 0 0 1 1.3 0 1 0 1.6* 0 1 1 1.9 1 0 0 2 1 0 1 2.9 1 1 0 3.1* 1 1 1 * : To series 100k connected to VSEL1 from EN pin. Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 4 is a registered trademark of Richtek Technology Corporation. DS5707/A-04 September 2020 RT5707/A Absolute Maximum Ratings        (Note 1) VIN, SW, EN, VSEL1, VSEL2, VSEL3, VOUT -------------------------------------------------------------------Power Dissipation, PD @ TA = 25°C WL-CSP-8B 0.9x1.6 (BSC) --------------------------------------------------------------------------------------------Package Thermal Resistance (Note 2) WL-CSP-8B 0.9x1.6 (BSC), θJA --------------------------------------------------------------------------------------Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------Junction Temperature Range -------------------------------------------------------------------------------------------Storage Temperature Range -------------------------------------------------------------------------------------------ESD Susceptibility (Note 3) HBM (Human Body Model) ---------------------------------------------------------------------------------------------- Recommended Operating Conditions      −0.3V to 6V 0.84W 118.5°C/W 260°C 150°C −65°C to 150°C 2kV (Note 4) Supply Input Voltage -----------------------------------------------------------------------------------------------------RT5707 Output Current (5.5V ≥ VIN ≥ (VOUT_NOM + 0.7V) ≥ 3V) ---------------------------------------------RT5707A Output Current (5.5V ≥ VIN ≥ (VOUT_NOM + 0.7V) ≥ 3V) -------------------------------------------Junction Temperature Range -------------------------------------------------------------------------------------------Ambient Temperature Range -------------------------------------------------------------------------------------------- 2.2V to 5.5V 0mA to 600mA 0mA to 400mA −40°C to 125°C −40°C to 85°C Electrical Characteristics (VIN = 3.6V, CIN = COUT = 10μF, L1 = 2.2μH, TA = 25°C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Unit -- 2 2.15 V -- 0.1 0.4 V BUCK Regulator Under-Voltage Lockout Rising Threshold VUVLOR Under-Voltage Lockout Hysteresis VUVLO_HYS VIN rising VOUT_ACC10 VOUT = 1.8V, IOUT = 10mA 2.5 -- 2.5 VOUT_ACC100 VOUT = 1.8V, IOUT = 100mA 2 -- 2 IQ_Non-SW VOUT = 1.8V, IOUT = 0A, EN = VIN, non-switching -- 360 800 IQSW VOUT = 1.8V, IOUT = 0A, EN = VIN, switching -- 460 1200 Shutdown Current ISHDN EN = GND -- 0.2 1 A Switching Frequency f SW VOUT = 1.8V, CCM mode -- 1.2 -- MHz UGATE Current Limit ICL_UG 3V  VIN  5.5V 1 1.2 1.4 0.68 0.78 0.88 LGATE Current Limit ICL_LG 3V  VIN  5.5V 1 1.2 1.4 0.55 0.68 0.8 UGATE RON RON_UG IOUT = 50mA -- 350 -- m LGATE RON RON_LG IOUT = 50mA -- 250 -- m VOUT Voltage Accuracy Input Quiescent Current Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS5707/A-04 September 2020 RT5707 RT5707A RT5707 RT5707A % nA A A is a registered trademark of Richtek Technology Corporation. www.richtek.com 5 RT5707/A Parameter Symbol Test Conditions Min Typ Max Unit Output Discharge Resistor RDIS EN = GND, IOUT = 10mA -- 10 --  VOUT Pin Input Leakage IVOUT VOUT = 2V, EN = VIN -- 100 -- nA VOUT Minimum Off Time tOFF_MIN -- 80 -- ns VOUT Minimum On Time tON_MIN VOUT = 1.8V, VIN = 3.6V -- 420 -- ns Line Regulation VOUT_LineReg VOUT = 1.8V, IOUT = 100mA, VIN = 2.2V to 5.5V -- 0.1 -- %/V VOUT_LoadReg1 VOUT = 1.8V, including PFM operation -- 0.001 -- VOUT_LoadReg2 VOUT = 1.8V, only CCM operation -- 0.0005 -- Over-Temperature Protection TOTP -- 150 -- °C Over-Temperature Protection Hysteresis TOTP_HYS -- 20 -- °C Auto 100% Duty Cycle Leave Detection Threshold VTH_100+ Rising VIN, 100% mode is left with VIN = VOUT + VTH_100+ 150 250 350 mV Auto 100% Duty Cycle Enter Detection Threshold VTH_100- Falling VIN, 100% mode is entered with VIN = VOUT + VTH_100- 85 200 290 mV Regulator Start Up Delay Time tSS_EN IOUT = 0mA, EN = GND to VIN, VOUT starts rising -- 0.1 -- ms Regulator Soft Start Time tSS VOUT = 1.8V, IOUT = 10mA, EN = VIN -- 0.7 -- ms Load Regulation %/mA Timing Logic Input (EN, VSEL1, VSEL2 and VSEL3) Input High Threshold VIH VIN = 2.2V to 5.5V 1.2 -- -- V Input Low Threshold VIL VIN = 2.2V to 5.5V -- -- 0.4 V Input Pin Bias Current IIN -- 10 -- nA 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 under natural convection (still air) at TA = 25°C with the component mounted on a high effectivethermal-conductivity four-layer test board on a JEDEC 51-7 thermal measurement standard. Note 3. Devices are ESD sensitive. Handling precaution is recommended. Note 4. The device is not guaranteed to function outside its operating conditions. Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 6 is a registered trademark of Richtek Technology Corporation. DS5707/A-04 September 2020 RT5707/A Typical Application Circuit For the RT5707 VIN 2.2V to 5.5V A2 CIN 10µF B1 C1 VIN or GND D1 VIN or GND D2 VIN or GND RT5707 VIN SW VOUT L1 2.2µH A1 COUT 10µF C2 Main System EN VSEL1 VSEL2 VSEL3 GND B2 Recommended components information for the RT5707 as below table : Reference Part Number Description Package Manufacturer CIN, COUT GRM155R60J106ME15 10F/6.3V/X5R 0402 Murata L1 1239AS-H-2R2M 2.2H 2520 Murata For the RT5707A VIN 2.2V to 5.5V A2 VIN SW CIN 4.7µF B1 C1 VIN or GND D1 VIN or GND D2 VIN or GND L1 2.2µH RT5707A VOUT A1 COUT 10µF C2 Main System EN VSEL1 VSEL2 VSEL3 GND B2 Recommended components information for the RT5707A as below table : Reference Part Number Description Package Manufacturer CIN GRM155R60J475ME47 4.7F/6.3V/X5R 0402 Murata COUT GRM155R60J106ME15 10F/6.3V/X5R 0402 Murata L1 DFE201610E-2R2M=P2 2.2H 2016 Murata Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS5707/A-04 September 2020 is a registered trademark of Richtek Technology Corporation. www.richtek.com 7 RT5707/A Typical Operating Characteristics Efficiency vs. Load Current 100 95 90 90 Efficiency (%) Efficiency (%) Efficiency vs. Load Current 100 VIN = 3.6V VIN = 4.2V VIN = 5V 85 80 75 80 70 VIN = 2.5V VIN = 3V VIN = 3.6V 60 50 70 40 VOUT = 3.3V 65 0.001 0.01 0.1 1 10 100 VOUT = 0.7V 30 0.001 1000 0.01 0.1 Load Current (mA) 1000 70 1.8 VIN = 5V VIN = 4.2V VIN = 3.8V 1.6 Output Voltage Ripple (mVpp) Switching Frequency (MHz)1 100 Output Voltage Ripple Switching Frequency vs. Load Current 1.4 1.2 1.0 0.8 0.6 0.4 0.2 VOUT = 3.3V 0.0 0 100 200 300 400 500 60 50 40 30 VIN = 5.5V VIN = 5V VIN = 4.2V 20 10 VOUT = 3.3V 0 0.001 600 0.01 0.1 1 10 100 1000 Load Current (mA) Load Current (mA) Quiescent Current Output Voltage Ripple 1.0 22.5 VOUT = 0.7V 20.0 VIN = 2.5V VIN = 3V VIN = 3.6V 15.0 12.5 10.0 7.5 0.001 0.9 0.8 0.7 Switching 0.6 0.5 Non-switching 0.4 0.3 0.01 0.1 1 10 100 Load Current (mA) Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 8 VOUT = 3.3V Quiescent Current (μA) Output Voltage Ripple (mVpp) 10 Load Current (mA) 2.0 17.5 1 1000 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 Input Voltage (V) is a registered trademark of Richtek Technology Corporation. DS5707/A-04 September 2020 RT5707/A Quiescent Current 1.0 1.0 0.9 Shutdown Current (μA)1 0.9 Quiescent Current (μA) Shutdown Current 0.8 0.7 0.6 Switching 0.5 0.4 Non-switching 0.3 0.2 0.1 VOUT = 1.8V 0.0 0.8 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 2.2 2.5 2.8 3.1 3.4 3.7 4.0 4.3 4.6 4.9 5.2 5.5 2.2 2.5 2.8 3.1 3.4 3.7 4.0 4.3 4.6 4.9 5.2 5.5 Input Voltage(V) Input Voltage (V) PSM Mode Operation VOUT_AC (50mV/Div) PWM Mode Operation VOUT_AC (50mV/Div) VSW (5V/Div) VSW (5V/Div) VIN = 5V, VOUT = 3.3V, IOUT = 300mA VIN = 5V, VOUT = 3.3V, IOUT = 50mA IL (200mA/Div) IL (200mA/Div) Time (4μs/Div) Time (400ns/Div) Power On with Resistor Load Power On with Resistor Load VOUT (2V/Div) VOUT (2V/Div) VEN (5V/Div) VEN (5V/Div) VIN = 5V, VOUT = 3.3V, IOUT about = 100mA (EN enable) IL (500mA/Div) IL (500mA/Div) Time (400μs/Div) Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS5707/A-04 VIN = 3.6V, VOUT = 3.3V, IOUT about = 300mA (EN enable) September 2020 Time (400μs/Div) is a registered trademark of Richtek Technology Corporation. www.richtek.com 9 RT5707/A Load Transient Response Load Transient Response VIN = 5V, VOUT = 3.3V, IOUT 100mA to 290mA, TR = TF = 1μs VIN = 5V, VOUT = 3.3V, IOUT 5mA to 290mA, TR = TF = 1μs VOUT_AC (50mV/Div) VOUT_AC (50mV/Div) IL (100mA/Div) IL (100mA/Div) VOUT_AC (50mV/Div) Time (200μs/Div) Time (200μs/Div) Load Transient Response Load Transient Response VIN = 5V, VOUT = 3.3V, IOUT 50mA to 500mA, TR = TF = 1.6μs VIN = 5V, VOUT = 3.3V, IOUT 50mA to 450mA, TR = TF = 1μs VOUT_AC (50mV/Div) IL (200mA/Div) IL (200mA/Div) Time (200μs/Div) Time (200μs/Div) 100% Duty Cycle Entry and Leave Operation VOUT (500mV/Div) VIN = 2.2V to 5.5V (Ramp rise), VOUT = 3.3V, IOUT = 30mA VIN (2V/Div) IL (200mA/Div) Time (20ms/Div) Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 10 is a registered trademark of Richtek Technology Corporation. DS5707/A-04 September 2020 RT5707/A Application Information The RT5707/A is a synchronous low voltage step-down converter that can support the input voltage range from 2.2V to 5.5V and the output current can be up to 600mA, peak to 1A (RT5707) / 400mA, peak to 0.5A (RT5707A). Internal compensation are integrated to minimize external component count. Protection features include over-current protection, under-voltage protection and over-temperature protection. Inductor Selection The recommended power inductor is 2.2μH and inductor saturation current rating choose follow over current protection design consideration. In applications, it needs to select an inductor with the low DCR to provide good performance and efficiency. 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 : V VIN IRMS = IOUT(MAX)  OUT  1 VIN 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 offer much relief. To 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. Thermal Considerations The junction temperature should never exceed the absolute maximum junction temperature TJ(MAX), listed under Absolute Maximum Ratings, to avoid permanent damage to the device. The maximum allowable power dissipation depends on the thermal resistance of the IC package, the PCB layout, the rate of surrounding airflow, and the difference between the junction and ambient temperatures. The maximum power dissipation can be calculated using 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 continuous operation, the maximum operating junction temperature indicated under Recommended Operating Conditions is 125°C. The junction-to-ambient thermal resistance, θJA, is highly package dependent. For a WLCSP-8B 0.9x1.6 (BSC) package, the thermal resistance, θJA, is 118.5°C/W on a standard JEDEC 51-7 high effectivethermal-conductivity four-layer test board. The maximum power dissipation at TA = 25°C can be calculated as below PD(MAX) = (125°C − 25°C) / (118.5°C/W) = 0.84W for a WL-CSP-8B 0.9x1.6 (BSC) package. The maximum power dissipation depends on the operating ambient temperature for the fixed TJ(MAX) and the thermal resistance, θJA. The derating curves in Figure 2 allows the designer to see the effect of rising ambient temperature on the maximum power dissipation. 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 as described in a later section. The output ripple, ΔVOUT, is determined by : 1  VOUT  IL ESR + 8  f  C SW OUT   Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS5707/A-04 September 2020 is a registered trademark of Richtek Technology Corporation. www.richtek.com 11 RT5707/A Maximum Power Dissipation (W)1 1.0 Four-Layer PCB 0.9 Layout Considerations For high frequency switching power supplies, the PCB layout is important to get good regulation, high efficiency and stability. The following descriptions are the guidelines for better PCB layout. 0.8 0.7 0.6 0.5  For good regulation, place the power components as close as possible. The traces should be wide and short enough especially for the high-current loop. 0.4 0.3 0.2 Shorten 0.1 the SW node trace length and make it wide. 0.0 0 25 50 75 100 125 Ambient Temperature (°C) Figure 2. Derating Curve of Maximum Power Dissipation Table 2. Protection Trigger Condition and Behavior Threshold Refer to Electrical Spec. Protection Method Reset Method UGATE Current Limit ISW > 1.2A (Typ.) Turn off UG MOS ISW < 1.2A (Typ.) LGATE Current Limit ISW > 1.2A (Typ.) Turn on LG MOS ISW < 1.2A (Typ.) UGATE Current Limit ISW > 0.78A (Typ.) Turn off UG MOS ISW < 0.78A (Typ.) LGATE Current Limit ISW > 0.68A (Typ.) Turn on LG MOS ISW < 0.68A (Typ.) UVLO VUVLOF < 1.9V (Typ.) Shutdown VUVLOR > 2V (Typ.) OTP Temperature > 150°C (Typ.) Shutdown Temperature < 130°C (Typ.) Protection Type RT5707 RT5707A Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 12 is a registered trademark of Richtek Technology Corporation. DS5707/A-04 September 2020 RT5707/A TOP View The inductor should be connected to this pin with the shortest path. VIN L1 CIN SW VIN EN GND VSEL1 VOUT VSEL2 VSEL3 VOUT VIN The input capacitor Cin connected to this pin should be grounded with the shortest path COUT The output capacitor COUT connected to this pin should be grounded with the shortest path The VSEL1, VSEL2, VSEL3 and EN pin should be connected to MCU or GND. Do not floating these pins. Figure 3. RT5707 PCB Layout Guide Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS5707/A-04 September 2020 is a registered trademark of Richtek Technology Corporation. www.richtek.com 13 RT5707/A TOP View VIN The inductor should be connected to this pin with the shortest path. CIN L1 SW VIN EN GND VSEL1 VOUT VSEL2 VSEL3 VOUT VIN The input capacitor Cin connected to this pin should be grounded with the shortest path COUT The output capacitor COUT connected to this pin should be grounded with the shortest path The VSEL1, VSEL2, VSEL3 and EN pin should be connected to MCU or GND. Do not floating these pins. Figure 4. RT5707A PCB Layout Guide Copyright © 2020 Richtek Technology Corporation. All rights reserved. www.richtek.com 14 is a registered trademark of Richtek Technology Corporation. DS5707/A-04 September 2020 RT5707/A Outline Dimension Symbol Dimensions In Millimeters Dimensions In Inches Min Max Min Max A 0.500 0.600 0.020 0.024 A1 0.170 0.230 0.007 0.009 b 0.240 0.300 0.009 0.012 D 1.560 1.640 0.061 0.065 D1 E 1.200 0.860 0.047 0.940 0.034 0.037 E1 0.400 0.016 e 0.400 0.016 8B WL-CSP 0.9x1.6 Package (BSC) Copyright © 2020 Richtek Technology Corporation. All rights reserved. DS5707/A-04 September 2020 is a registered trademark of Richtek Technology Corporation. www.richtek.com 15 RT5707/A Footprint Information Package Number of Pin WL-CSP0.9x1.6-8(BSC) 8 Type NSMD SMD Footprint Dimension (mm) e 0.400 A B 0.240 0.340 0.270 0.240 Tolerance ±0.025 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 16 DS5707/A-04 September 2020