RT6150A RICHTEK | Alldatasheet
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Technical content
Features
Fixed Frequency Operation with Battery Voltages Synchronous Rectification : Up to 90% Efficiency Up to 800mA Continuous Output Current VOUT Disconnected from VIN during Shutdown Power Save Mode (PSM) Enable Control <1μ μμ μμA Shutdown Current Input Voltage Range: 1.8V to 5.5V Fixed 3.3V and Adjustable Output Voltage Options from 2.5V to 5.5V 10-Lead WDFN Packages RoHS Compliant and Halogen Free Simplified Application Circuit
Ordering Information
Note : Richtek products are : RoHS compliant and compatible with the current require- ments of IPC/JEDEC J-STD-020. Suitable for use in SnPb or Pb-free soldering processes. VIN VINA EN VOUT FB RT6150A/B PS GND Battery VOUT LX2LX1 Enable RT6150A/B- Package Type QW : WDFN-10L 3x3 (W-Type) QW : WDFN-10L 2.5x2.5 (W-Type) Lead Plating System G : Green (Halogen Free and Pb Free) A : WDFN-10L 3x3 B : WDFN-10L 2.5x2.5 Output Voltage 33 : 3.3V (Only for RT6150B)
DS6150A/B-06 July 2018www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Functional Pin Description Pin No. Pin Name Pin Function 1 VOUT Output of the buck-boost converter. Connect a capacitor between the VOUT and GND. 2 LX2 Second switch node. Connect this pin to the inductor. 3, 9, 11 (Exposed Pad) GND Power ground. The exposed pad must be soldered to a large PCB and connected to GND for maximum power dissipation. 4 LX1 First switch node. Connect this pin to the inductor. 5 VIN Power input. Connect an at least 10 F capacitor between the VIN pin and GND. 6 EN Enable control input for the buck-boost converter. 7 PS PSM control input. Pull low for PSM operation and pull high for fixed switching frequency operation. 8 VINA Supply voltage input for control circuit. 10 FB Feedback input. For adjustable versions, connect a resistive divider to set the output voltage and it can be adjusted from 2.5V to 5.5V; For fixed version, must be connected to VOUT. Marking Information Pin Configuration (TOP VIEW) WDFN-10L 3x3 / WDFN-10L 2.5x2.5 VOUT LX2 VIN LX1 FB GND VINA EN PS GND GND 0N= : Product Code YMDNN : Date Code RT6150AGQW 0N=YM DNN RT6150BGQW 00W 00 : Product Code W : Date Code 03W 03 : Product Code W : Date Code RT6150B-33GQW
DS6150A/B-06 July 2018 www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Functional Block Diagr am VIN LX1 Gate Driver LX2 CTRL VINA ISENSE OCP Temp Control OTP PS EN OSC CMP Slop Comp Zero Current VOUT VPSM -AMP GND CC RC SS VREF FB Operation The RT6150A/B is a synchronous average current mode switching Buck-Boost converter designed to maintain a fixed output voltage from an input supply that can be above, equal, or below the output voltage. The average inductor current is regulated by a fast current regulator which is controlled by a voltage control loop. The voltage error amplifier gets its feedback input from the FB pin. For adjustable output voltage, a resistive voltage divider must be connected to the FB pin. When VIN is greater than VOUT, the device operates in Buck mode. When VIN is lower than VOUT, the device operates in Boost mode. When VIN is close to VOUT, the RT6150A/B automatically enters Buck-Boost mode. In Buck- Boost mode, the converter will maintain the regulation for output voltage and keep a minimum current ripple in the inductor to guarantee good performance.
DS6150A/B-06 July 2018www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation.
Electrical Characteristics
(VIN = VOUT = 3.6V, TA = 25°C, unless otherwise specified.) Parameter Symbol Test Conditions Min Typ Max Unit Input Voltage UVLO High-Level -- 1.65 1.8 V Low-Level 1.4 1.55 -- Feedback Voltage V FB V PS = VIN 0.495 0.5 0.505 V Feedback Input Current V FB = 0.5V -- 1 50 nA Quiescent Current IOUT = 0mA, PS = 0V (Note 5) Power Save Mode -- 60 -- A EN = 0V, not including switch leakage shutdown -- 0.1 1 N-MOSFET Switch Leakage -- 0.1 5 A P-MOSFET Switch Leakage -- 0.1 10 A N-MOSFET Switch On Resistance RDS(ON)_N -- 0.15 -- P-MOSFET Switch On Resistance RDS(ON)_P -- 0.15 -- Switch Current Limit I LIM V IN = 3.6V 1.6 -- -- A Oscillator Frequency f OSC 0.8 1 1.2 MHz Soft-Start Time t SS Time from when EN signal asserts to output voltage IOUT = 0mA -- 0.65 1 ms Absolute Maximum Ratings (Note 1) Power Dissipation, PD @ TA = 25°C Package Thermal Resistance (Note 2) ESD Susceptibility (Note 3) Recommended Operating Conditions (Note 4)
DS6150A/B-06 July 2018 www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Note 1. Stresses beyond those listed under “Absolute Maximum Ratings ” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may affect device reliability. Note 2. θ JA is measured at T A = 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. Note 5. Current measurements are performed when the output are not switching. Parameter Symbol Test Conditions Min Typ Max Unit Logic-High 1.2 -- -- EN and PS Input Voltage Logic-Low -- -- 0.4 V EN and PS Input Current V EN = VPS = VIN -- 0.01 1 A Thermal Shutdown T SD -- 140 -- C
DS6150A/B-06 July 2018www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Typical Application Circuit VIN VINA EN LX2 VOUT FB RT6150A/B LX1 PS GND 3, 9, 11 (Exposed Pad) CIN COUT VIN VOUT L 10µF 20µF 2.2µH Enable 487k 86.6k
DS6150A/B-06 July 2018 www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Buck-Boost 3.3V Efficiency 100 1 10 100 1000 Output Current (mA) Efficiency (%) L = 2.2μH, COUT = 20μF, PS/SYNC = H VIN = 1.8V VIN = 2.4V VIN = 3.3V VIN = 4.2V VIN = 5.5V Buck-Boost 3.3V Efficiency 100 1 10 100 1000 Output Current (mA) Efficiency (%) L = 2.2μH, COUT = 20μF, PS/SYNC = L VIN = 1.8V VIN = 2.4V VIN = 3.3V VIN = 4.2V VIN = 5.5V Efficiency vs. Input Voltage 100 Input Voltage (V) Efficiency (%) IOUT = 500mA IOUT = 100mA IOUT = 10mA L = 2.2μH, COUT = 20μF, PS/SYNC = L Output Voltage vs. Input Voltage 3.0 3.1 3.2 3.3 3.4 3.5 3.6 Input Voltage (V) Output Voltage (V) Maximum Output Current vs. Input Voltage 250 500 750 1000 1250 1500 1750 2000 Input Voltage (V) Maximum Output Current (mA) 1 Output Voltage vs. Output Current 3.0 3.1 3.2 3.3 3.4 3.5 3.6 0 200 400 600 800 1000 Output Current (mA) Output Voltage (V) Typical Operating Characteristics COUT = 20μF, PS = L VIN = 1.8V VIN = 2.4V VIN = 3.3V VIN = 4.2V VIN = 5V COUT = 20μF, PS = L IOUT = 500mA IOUT = 300mA IOUT = 100mA VOUT = 3.3V, COUT = 20μF, PS = H
DS6150A/B-06 July 2018www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Time (2.5ms/Div) Load Transient Response ILOAD (200mA/Div) VOUT_ac (100mV/Div) VIN = 3.3V, VOUT = 3.3V, IOUT = 200mA to 600mA, L = 2.2μH, COUT = 20μF Time (2.5ms/Div) Load Transient Response ILOAD (200mA/Div) VOUT_ac (100mV/Div) VIN = 3V, VOUT = 3.3V, IOUT = 200mA to 600mA, L = 2.2μH, COUT = 20μF Time (500ns/Div) Output Voltage Ripple VIN = 4.2V, VOUT = 3.3V, IOUT = 500mA, L = 2.2μH, COUT = 20μF LX2 (2V/Div) VOUT_ac (20mV/Div) LX1 (2V/Div) VIN = 2.5V, VOUT = 3.3V, IOUT = 500mA, L = 2.2μH, COUT = 20μF Time (500ns/Div) Output Voltage Ripple LX2 (2V/Div) VOUT_ac (20mV/Div) LX1 (2V/Div) Time (500ns/Div) Output Voltage Ripple VIN = 3.3V, VOUT = 3.3V, IOUT = 500mA, L = 2.2μH, COUT = 20μF LX2 (2V/Div) VOUT_ac (20mV/Div) LX1 (2V/Div) Time (2.5ms/Div) Load Transient Response ILOAD (200mA/Div) VOUT_ac (100mV/Div) VIN = 4.2V, VOUT = 3.3V, IOUT = 200mA to 600mA, L = 2.2μH, COUT = 20μF
DS6150A/B-06 July 2018 www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation.
Application Information
The RT6150A/B Buck-Boost DC-DC converter is designed for systems powered by one-cell Li-Ion or Li-Polymer battery with a typical voltage between 1.8V and 4.2V. They can also be used in systems powered by a double or triple cell Alkaline, NiCd, or NiMH battery with a typical terminal voltage between 1.8V and 5.5V. Additionally, the output voltage can be set between 2.5V and 5.5V. The controller monitors the average input current as well as the peak input current. With this, maximum input power can be controlled to achieve a safe and stable operation. To protect the device from overheating, an internal temperature sensor is implemented. Enable The device can be enabled or disenabled by the EN pin. When the EN pin is higher than the threshold of logic- high, the device starts operation 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. Soft-Start When the RT6150A/B is enabled, the output voltage will increase to its setting value within 1ms. During start-up period, the duty cycle and the peak current are limited to reduce high peak current flowing from the input. Output Voltage Setting There are fixed and adjustable output voltage versions available. To properly configure the fixed output voltage devices, the FB pin is used to sense the output voltage and must be connected directly to VOUT. At the adjustable versions, the output voltage is setting 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, and the current into FB pin is about 10nA generally. The current through divider resistor should be about 100 times larger than the current into FB pin in order to neglect the FB input current. The suggested value For example, an output voltage of 3.3V is needed. It is recommended to use a 487kΩ resistor for R1. For better transient response performance, adding a feedforward capacitor in parallel with R1 is recommended. The value for the feedforward capacitor can be calculated using equation as below : Cff = [(487k/R1) x 20] −20 (pF) OUT FB VR1 = R2 1 V Power Save Mode The PS pin can be used to select different operation modes. To enable Power Save Mode (PSM), the PS pin must be set at low. The PSM is used to improve the efficiency at light load. If the power save mode is disabled by pulling high the PS pin, the converter will operate in PWM mode with fixed switching frequency. 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. VINA voltage must be greater than 1.65V to enable the converter. During operation, if VINA voltage drops below 1.55V, the converter is disabled until the supply exceeds the UVLO rising threshold. The RT6150A/B automatically restarts if the input voltage recovers to the input voltage UVLO high level. Thermal Shutdown The device has a built-in temperature sensor which monitors the internal junction temperature. If the 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 designed to avoid unstable operation at IC temperatures near the over temperature threshold. for R2 is 80kΩ to 500kΩ, and the value of R1 is depended on the needed output voltage. Output voltage can be calculated by equation as below :
DS6150A/B-06 July 2018www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. where f is the minimum switching frequency. L1 is the minimum inductor value for Buck mode operation. VIN(MAX) is the maximum input voltage. L2 is the minimum inductance, for Boost mode operation. V IN(MIN) is the minimum input voltage. The recommended minimum inductor value is either L1 or L2 whichever is higher. For example, a suitable inductor value is 2.2μH for generating a 3.3V output voltage from a Li-Ion battery with the range from 1.8V to 4.2V. The recommended inductor value range is between 1.5μH and 4.7μH. In general, a higher inductor value offers better performance in high voltage conversion condition. Input Capacitor Selection At least a 10μF input capacitor is recommended to improve transient behavior of the regulator and EMI behavior of the total power supply circuit. A ceramic capacitor placed as close as possible to the VIN and GND pins of the IC is recommended. Output Capacitor Selection The output capacitor selection determines the output voltage ripple and transient response. It is recommended to use ceramic capacitors placed as close as possible to the VOUT and GND pins of the IC. If, for any reason, the application requires the use of large capacitors which can not be placed close to the IC, using a small ceramic capacitor in parallel to the large one is recommended. This small capacitor should be placed as close as possible to the VOUT and GND pins of the IC. The output voltage ripple for a given output capacitor is expressed as follows : OUT IN OUTOUT 2IN OSC OUT LOAD OUT INOUT OUT OUT OSC V( V V )V, p e a k ( B u c k ) = V8 L ( f ) C I( V V )V, p e a k ( B o o s t ) = CVf If the RT6150A/B operates in Buck mode, the worst-case voltage ripple occurs at the highest input voltage. When the RT6150A/B operates in boost mode, the worst-case voltage ripple occurs at the lowest input voltage. The maximum voltage of overshoot or undershoot, is inversely proportional to the value of the output capacitor. To ensure stability and excellent transient response, it is recommended to use a minimum of 10 μF/X7R/1206 capacitors at the output. For surface mount applications, Taiyo Yuden or TDK ceramic capacitors, X7R series Multi- layer Ceramic Capacitor is recommended. A capacitor with a value in the range of the calculated minimum should be used. This is required to maintain control loop stability. There are no additional requirements regarding minimum ESR. Low ESR capacitors should be used to minimize output voltage ripple. Larger capacitors will cause lower output voltage ripple as well as lower output voltage drop during load transients. 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 : P D(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. For WDFN-10L 3x3 package, the thermal resistance, θJA, is 30.5°C/W on a standard JEDEC 51-7 four-layer thermal test board. For WDFN-10L 2.5x2.5 package, the thermal resistance, θ JA, is 40.9°C/W on a standard JEDEC 51-7 four-layer thermal test board. The maximum power dissipation at T A = 25°C can be calculated by the following formula : OUT IN(MAX) OUT LI N ( M A X ) VV VL1 > (H)fI V IN(MIN) OUT IN(MIN) LO U T VV VL2 > (H) fI V Inductor Selection To properly configure the Buck-Boost converter, an inductor must be connected between the LX1 and LX2 pins. To estimate the inductance value, two equations are listed as below :
DS6150A/B-06 July 2018www.richtek.com ©Copyright 2018 Richtek Technology Corporation. All rights reserved. is a registered trademark of Ric htek Technology Corporation. Outline Dimension Dimensions In Millimeters Dimensions In Inches Symbol 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 0.180 0.300 0.007 0.012 D 2.950 3.050 0.1 16 0.120 D2 2.300 2.650 0.091 0.104 E 2.950 3.050 0.1 16 0.120 E2 1.500 1.750 0.059 0.069 e 0.500 0.020 L 0.350 0.450 0.014 0.018 W-Type 10L DFN 3x3 Package 1 122 Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated. DETAIL A Pin #1 ID and Tie Bar Mark Options D E A L be SEE DETAIL A
DS6150A/B-06 July 2018 www.richtek.com 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. Customers should obtain the latest relevant information and data sheets before p lacing orders and should verify that such information is current and complete. Richtek cannot assume responsibility for use of any circuitry other than circuit ry entirely embodied in a Richtek product. Information furnished by Richtek is believed to be accurate and reliable. However, no responsibility is assumed by Ric htek 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 i mplication or otherwise under any patent or patent rights of Richtek or its subsidiaries. W-Type 10L DFN 2.5x2.5 Package 1 122 Note : The configuration of the Pin #1 identifier is optional, but must be located within the zone indicated. DETAIL A Pin #1 ID and Tie Bar Mark Options 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 2.400 2.600 0.094 0.102 D2 1.950 2.050 0.077 0.081 E 2.400 2.600 0.094 0.102 E2 1.150 1.250 0.045 0.049 e L 0.350 0.450 0.014 0.018 Symbol Dimensions In Millimeters Dimensions In Inches 0.500 0.020