DN05082/D Design Note – DN05082/D 15 W HVDCP Quick Charge™ 3.0 Compatible CV/CC Charger Device Application NCP4371AAC NCP1361EABAY NCP4305D Quick Charge™ 3.0, Cell Phone, Laptop Charger Input Voltage 90 to 265 Vac Output Power Topology I/O Isolation 15 Watts Nominal Flyback Isolated (3 kV) Output Voltage Output Ripple Max Output Current Min Output Current Output Specification Nominal: 5.0 Vdc, Min: 3.6 Vdc, Max: 12 Vdc TBD @ Full Load 2.0 A @ 5 Vdc, 1.25 A @ 12 Vdc 0A Efficiency Input Protection Operating Temp. Range Cooling Method No-load Power Consumption See Efficiency Charts Fuse 0 °C to +50 °C Passive Cooling <75 mW @ 90 – 265 Vac divider R18, R16 is used to set the output voltage UVP/OVP levels. The presented design has the levels set as follows: VUVP = 3.2 V and VOVP = 15.0 V. Introduction This design note describes a 15 W, universal AC mains, isolated Quasi-Resonant flyback converter compatible with Qualcomm’s High Voltage Dedicated Charging Port Quick Charge™ 3.0 Class A specification. The converter provides adjustable output voltage in a range from 3.6 Vdc to 12 Vdc. It maintains maximum output power 15 W at full range of the voltage output and at same time it limits the maximum output current to 2.0 A. The design is targeted for smart phone and tablet charger applications. The charger design utilizes ON Semiconductor’s new NCP4371 Qualcomm Quick Charge™ 3.0 Controller, NCP1361E Quasi-Resonant Controller and NCP4305 Synchronous Rectification controller. Circuit Description 1. Input Circuitry The input circuitry is formed by a fuse F1, simple EMI filter consisting of capacitor CX1, common and differential mode choke inductors L1 and L4, and the bridge rectifier B1. 2. NCP1361EABAY Control Circuitry The NCP1361EABAY is a 6-pin Quasi-Resonant Controller in TSOP6 package. It features output over and under voltage protection sensing via Vs/ZCD pin, which eliminates a need for an additional circuitry to provide output voltage fault protection. The resistor September 2015, Rev. 0 Resistors R14 and R15 are the primary current sense resistors. To filter the turn-on spikes, a small RC filter consisting of R12 and C11 is added into the signal path between CS pin and current sense resistors. Regulation information from secondary side controller is transferred via optocoupler to primary side and connected to NCP1361EABAY FB pin. The primary controller is supplied via auxiliary winding. Due to wide output voltage regulation range the VCC supply circuitry requires a voltage regulator consisting of Zener diode D11, R24 and a small signal transistor BSS64L. Thus the controller is protected from seeing high auxiliary voltage. R1 and R2 are high impedance start-up resistors. R3, R4, R5 and C19 forms a RCD clamp to limit Q1 MOSFET drain voltage spikes. 3. NCP4371 Qualcomm QC3.0 Controller The NCP4371AAC is an 8-pin CV/CC (constant voltage / constant current) controller in SOIC8 package. It resides on the isolated secondary side of the converter. It allows receiving and decoding control commands from Qualcomm QC3.0 compatible Portable Device. Output USB-bus voltage can be adjusted in a range from 3.6 V to 12.0 V. The NCP4371AAC controller provides a control feedback www.onsemi.com 1 DN05082/D to the primary side via an optocoupler driven by the DRIVE pin. R28, C20 and C21 form a compensation network for the constant voltage regulation loop. R27 is an output current sensing resistor. A voltage drop across the R27 is sensed at ISNS input pin and used for output current regulation. R17, C12 and C13 form a compensation network for the output current regulation. The NCP4371 features internal discharge circuitry via VCC pin. In case the internal discharge strength is not sufficient an external discharge resistor R13 connected to the DISCHARGE pin can be used. The output capacitors are required to be discharged either a request for a lower VOUT is received or a USB cable unplug event is detected. By selection of the output current sensing resistor value (R27) and current limit device option of the NCP4371 the user can scale a maximum output power and maximum current independently. In case of the presented design we selected power profile A and current limit C. Together with the R27 = 11 mΩ we will get a following power profile: VBUS [V] 12.0 9.0 5.0 3.6 IOUT(max) [A] 1.25 1.67 2.00 2.00 Key Features Universal AC input range (90 – 265 Vac). Input filter for conducted EMI attenuation. Very low standby and no-load power consumption. Quasi-Resonant current mode control with Valley Switching Valley lockout avoids audible noise at valley jumping operation Secondary synchronous rectification control for high efficiency Qualcomm protocol controller supports QC2.0 and QC3.0 Output 5 V / 2.00 A, 9 V / 1.67 A and 12 V / 1.25 A Highly configurable power and current limit profiles Standby power <75 mW @ 5 V output Support output capacitor discharge function while portable device is unplugged or during transition from higher to lower output voltage Smooth output voltage transition POUT(max) [W] 15.0 15.0 10.0 7.2 Maximum output power is scaled to 15.0 W, while the maximum output current is limited to 2.0 A as restricted by USB Type-A connector. 4. NCP4305D Synchronous Rectification Controller The flyback transformer secondary voltage is rectified by a NCP4305D synchronous rectifier in order to achieve higher efficiency. The NCP4305D senses a voltage drop across output MOSFET transistor Q2 and turns it on and off accordingly. Resistors R20 and R21 allows to adjust minimum MOSFET driver on and off times. The Light-Load Detect (LLD) circuitry allows putting the NCP4305D controller into a stand-by mode in case of light or no-load operating condition. The NCP4305D is supplied via a Schottky diode D6 under normal operating conditions. If the output voltage falls below 4.5V the NCP4305D is supplied by the transformer forward voltage via the circuitry consisting of D8, R6, C15, R25, D7, D9 and Q3. This situation will occur when the converter is running in Constant Current mode or when the requested output voltage from the Portable Device is below 5.0V. September 2015, Rev. 0 www.onsemi.com 2 DN05082/D Circuit Diagram September 2015, Rev. 0 www.onsemi.com 3 DN05082/D PCB Layout Demonstration Board Top September 2015, Rev. 0 Bottom www.onsemi.com 4 DN05082/D Standby Power at No Load at 5V Output 70 60 Pin [mW] 50 40 30 20 10 0 80 130 180 230 280 Input Voltage [Vac] 4-Point Average Efficiency at 5 V Output 90 Efficiency [%] 88 86 84 82 80 70 120 170 220 270 Input Voltage [Vac] September 2015, Rev. 0 www.onsemi.com 5 DN05082/D Efficiency vs. Load Curves at 5 V Output 95.00 Efficiency [%] 90.00 85.00 90 Vac 120 Vac 80.00 230 Vac 265 Vac 75.00 70.00 0.00 0.50 1.00 1.50 2.00 2.50 Iout [A] Output V/A Characteristics at 5 V Output 6.00 5.00 Vout [V] 4.00 90 Vac 3.00 120 Vac 2.00 230 Vac 265 Vac 1.00 0.00 0.00 0.50 1.00 1.50 2.00 2.50 Iout [A] September 2015, Rev. 0 www.onsemi.com 6 DN05082/D 4-Point Average Efficiency at 9 V Output 90 Efficiency [%] 88 86 84 82 80 70 120 170 220 270 Input Voltage [Vac] Efficiency vs. Load Curves at 9 V Output 95.00 Efficiency [%] 90.00 85.00 90 Vac 120 Vac 80.00 230 Vac 265 Vac 75.00 70.00 0.00 0.50 1.00 1.50 2.00 Iout [A] September 2015, Rev. 0 www.onsemi.com 7 DN05082/D Output V/A Characteristics at 9 V Output 10.00 9.00 8.00 Vout [V] 7.00 6.00 90 Vac 5.00 120 Vac 4.00 230 Vac 3.00 265 Vac 2.00 1.00 0.00 0.00 0.50 1.00 1.50 2.00 2.50 Iout [A] 4-Point Average Efficiency at 12 V Output 90 Efficiency [%] 88 86 84 82 80 70 120 170 220 270 Input Voltage [Vac] September 2015, Rev. 0 www.onsemi.com 8 DN05082/D Efficiency vs. Load Curves at 12 V Output 95.00 Efficiency [%] 90.00 85.00 90 Vac 120 Vac 80.00 230 Vac 265 Vac 75.00 70.00 0.00 0.50 1.00 1.50 Iout [A] Output V/A Characteristics at 9 V Output 14.00 12.00 Vout [V] 10.00 8.00 90 Vac 6.00 120 Vac 230 Vac 4.00 265 Vac 2.00 0.00 0.00 0.50 1.00 1.50 2.00 Iout [A] September 2015, Rev. 0 www.onsemi.com 9 DN05082/D Output Voltage Change Transition from 5.0 V to 9.0 V Transition from 9.0 V to 12.0 V Continuous Mode Ramp Up and Down USB Cable Unplug Discharge Transient Response Load Change 0 to 1 A at 5 V September 2015, Rev. 0 Load Change 0 to 2 A at 5 V www.onsemi.com 10 DN05082/D September 2015, Rev. 0 www.onsemi.com 11 DN05082/D References [1] ON Semiconductor datasheet for NCP4371 Qualcomm Quick Charge™ 3.0 HVDCP Controller [2] ON Semiconductor datasheet for NCP1361 Low Power Offline Constant Current PWM CurrentMode Controller [3] ON Semiconductor datasheet for NCP4305 Secondary Side Synchronous Rectification Driver [4] Würth Electronic http://www.we-online.com/ Disclaimer: ON Semiconductor is providing this design note “AS IS” and does not assume any liability arising from its use; nor does ON Semiconductor convey any license to its or any third party’s intellectual property rights. This document is provided only to assist customers in evaluation of the referenced circuit implementation and the recipient assumes all liability and risk associated with its use, including, but not limited to, compliance with all regulatory standards. ON Semiconductor may change any of its products at any time, without notice. September 2015, Rev. 0 www.onsemi.com 12