ACT4525 Rev 1.1, December 17th, 2015 40V/3.5A CV/CC Buck Converter with USB Auto –Detect Rechargeable Portable Device CV/CC regulation DC/DC converter FEATURES Pass Apple MFi Test 40V Input Voltage Surge 4.5V-36V Operational Input Voltage Dual 5.1V Outputs with 1% Accuracy Up to 3.5A Output Current 2.65A Constant Current Regulation for VOUT1 1.2A Constant Current Regulation for VOUT2 USB Auto-detect Support Apple 2.4A, Samsung and BC1.2 Devices Hiccup Mode Protection at Output Short 90% Efficiency at Full Load 0.5mA Low Standby Input Current 5.7V Output Over Voltage Protection Cord Voltage Drop Compensation Meet EN55022 Class B Radiated EMI Standard 8kV ESD HBM Protection on DP and DM SOP-8EP Package GENERAL DESCRIPTION ACT4525 is a wide input voltage, high efficiency step-down DC/DC converter that operates in either CV (Constant Output Voltage) mode or CC (Constant Output Current) mode. ACT4525 has separated output current limits for dual port CLA applications. With the separated current limits, the CLA can meet Apple’s MFi standard. ACT4525 provides up to 3.5A output current at 125kHz switching frequency. ACT4525 builds in USB autodetect algorithms to recognize Apple, Samsung, and BC1.2 devices to ensure maximum charge current to attached devices. ACT4525 utilize adaptive drive technique to achieve good EMI performance while main 90% efficiency at full load for mini size CLA designs. ACT4525 also built in output short circuit protection with hiccup mode. The average output current is reduced to below 6mA when output is shorted to ground. Other features include output over voltage protection and thermal shutdown. APPLICATIONS The devices are available in a SOP-8EP package and require very few external devices for operation. Car Charger Cigarette Lighter Adaptor (CLA) V/I Profile Vout1 5.25V Typical Application Circuit 5.10V 4.95V 3.20V 4.5V to 40V CSN2 CSN1 C3 22nF HSB SW IN ACT4525 C1 47μF C2 10μF CSP GND DP DM D1 SK54L Rcs2 50mΩ L1 33μH C4 C5 10μF 470μF Rcs1 25mΩ C6 2.2μF 5.1V/2.4A Vout Iout1 5.1V/1A 2.4A Vout D- C7 2.2μF D- D+ D+ GND GND 2.9A Vout2 5.25V 5.10V 4.95V 3.20V Iout2 1.1A * Patent Pending Innovative PowerTM -1- 1.3A www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 ORDERING INFORMATION PART NUMBER OPERATION TEMPERATURE RANGE PACKAGE FREQUENCY PACKING ACT4525YH-T -40°C to 85°C SOP-8EP 125kHz TAPE & REEL PIN CONFIGURATION CSP 1 8 HSB CSN1 2 7 SW 6 IN 5 DM ACT4525 CSN2 3 DP 4 GND EP SOP-8EP Top View Innovative PowerTM -2- www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 PIN DESCRIPTIONS PIN NAME DESCRIPTION 1 CSP Voltage Feedback Input. Connect to node of the inductor and output capacitor. CSP, CSN1 and CSN2 Kevin sensing is recommended. 2 CSN1 Output current sense negative input. Connect to the negative terminal of current sense resistor for VOUT1. 3 CSN2 Output current sense negative input. Connect to the negative terminal of current sense resistor for VOUT2. 4 DP Data Line Positive Input. Connected to D+ of attached portable device data line. This pin passes 8kV HBM ESD. 5 DM Data Line Negative Input. Connected to D- of attached portable device data line. This pin passes 8kV HBM ESD. 6 IN Power Supply Input. Bypass this pin with a 10μF ceramic capacitor to GND, placed as close to the IC as possible. 7 SW Power Switching Output to External Inductor. 8 HSB High Side Bias Pin. This provides power to the internal high-side MOSFET gate driver. Connect a 22nF capacitor from HSB pin to SW pin. 9 GND Ground and Heat Dissipation Pad. Connect this exposed pad to large ground copper area with copper and vias. ABSOLUTE MAXIMUM RATINGS PARAMETER VALUE UNIT -0.3 to 40 V SW to GND -1 to VIN +1 V HSB to GND VSW - 0.3 to VSW + 7 V -0.3 to +6 V 46 °C/W Operating Junction Temperature -40 to 150 °C Storage Junction Temperature -55 to 150 °C 300 °C IN to GND CSP, CSN1, CSN2, DP , DM to GND Junction to Ambient Thermal Resistance Lead Temperature (Soldering 10 sec.) : Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rating conditions for long periods may affect device reliability. Innovative PowerTM -3- www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 ELECTRICAL CHARACTERISTICS (VIN = 12V, TA = 25°C, unless otherwise specified.) Parameter Input Over Voltage Protection Symbol VIN_OVP Condition Rising Min Typ Max Units 40 42 44 V Input Over Voltage Hysteresis Input Over Voltage Response Time Input Under Voltage Lockout (UVLO) T_VIN_OVP VIN step from 30V to 45V VIN Rising Input UVLO Hysteresis 4 V 250 ns 4.5 V 200 mV Input Voltage Power Good Deglitch Time No OVP 40 ms Input Voltage Power Good Deglitch Time No UVP 10 us Input Standby Current Vin=12V, Vout=5.1V, Iload=0 500 uA Output Voltage Regulation CSP Output Over Voltage Protection (OVP) 5.05 Output rising Output Over Voltage Deglitch Time Output Voltage Cord Compensation 5.1 5.15 V 5.7 V 1.0 us Output current 2.4A -15% 100 +15% mV -10% 3.2 10% V Output Under Voltage Protection (UVP) VOUT VOUT falling UVP Hysteresis VOUT VOUT rising UVP Deglitch Time VOUT UVP Blanking Time at Startup 0.2 V 10 us 3.5 ms CC1 Rcs=25mΩ 2.50 2.65 2.80 A CC2 Rcs=50mΩ 1.1 1.2 1.3 A Output Constant Current Limit Hiccup Waiting Time 4.13 S 5.8 A Top FET Rdson 70 mΩ Bottom FET Rdson 4.7 Ω Top FET Cycle by Cycle Current Limit 4.5 Maximum Duty Cycle 99 Switching Frequency -10% Soft-start Time Innovative PowerTM % 125 2.0 -4- +10% kHz ms www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 ELECTRICAL CHARACTERISTICS (VIN = 12V, TA = 25°C, unless otherwise specified.) Parameter Symbol Condition Min Out Voltage Ripples Cout=470uF/22uF ceramic Line Transient Response Input 12V-40V-12V with 1V/us slew rate, Vout=5V, Iload=0A and 2.4A 4.75 80mA-1.0A-80mA load with 0.1A/us slew rate 4.9 Load Transient Response Vout=5V Typ Max 80 5.15 Units mV 5.25 V 5.4 V Thermal Shut Down 160 °C Thermal Shut Down Hysteresis 30 °C 8 kV ESD of DP, DM Innovative PowerTM HBM -5- www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 FUNCTIONAL BLOCK DIAGRAM HSB VIN PWM Controller UVLO 70mΩ USB Auto Detect Driver DP OVP Current Sense and Control CSP CSN1 SW 4.7Ω DM CSN2 GND FUNCTIONAL DESCRIPTION In some applications, the increased with output current potential voltage drop across compensation is based on the resistance. Output Current Sensing and Regulation Sense resistor is connected to CSP and CSN1, CSN2 respectively. The sensed differential voltages are compared with interval references to regulate currents. CC loop and CV loop are in parallel. The current loop response is allowed to have slower response compared to voltage loop. However, during current transient response, the inductor current overshoot/undershoot should be controlled within +/-25% to avoid inductor saturation. output voltage is to compensate the output cable. The high side feedback The compensation voltage is derived as: ΔVout = (VCSP-VCSN)*K This voltage difference could be added on the reference or turning the (VCSP-VCSN) voltage into a sink current at FB pin to pull Vout higher than programmed voltage. Cycle-by-Cycle Current Control The conventional cycle-by-cycle peak current mode is implemented with high-side FET current sense. The cord compensation loop should be very slow to avoid potential disturbance to the voltage loop. The voltage loop should be sufficiently stable on various cord compensation setting. Input Over Voltage Protection The converter is disabled if the input voltage is above 42V (+/-2V). Device resumes operation automatically 40ms after OVP is cleared. Thermal Shutdown If the TJ increases beyond 160°C, ACT4525 goes into HZ mode and the timer is preserved until T J drops by 30°C. Output Over Voltage Protection Device stops switching when output over-voltage is sensed, and resumes operation automatically when output voltage drops to OVP - hysteresis. Output Under-Voltage Protection / Hiccup Mode There is a under voltage protection (UVP) threshold. If the UVP threshold is hit for 10us, an over current or short circuit is assumed, and the converter goes into hiccup mode by disabling the converter and restarts after hiccup waiting period. Cord Compensation Innovative PowerTM -6- www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 APPLICATIONS INFORMATION Inductor Selection Output Capacitor The inductor maintains a continuous current to the output load. This inductor current has a ripple that is dependent on the inductance value. Higher inductance reduces the peak-to-peak ripple current. The trade off for high inductance value is the increase in inductor core size and series resistance, and the reduction in current handling capability. In general, select an inductance value L based on ripple current requirement: L= VOUT ×(VIN _VOUT ) VIN fSW ILOADMAX K RIPPLE The output capacitor also needs to have low ESR to keep low output voltage ripple. The output ripple voltage is: VRIPPLE I OUTMAX K RIPPLE RESR (1) With a selected inductor value the peak-to-peak inductor current is estimated as: VOUT ×(VIN _VOUT ) L ×VIN ×fSW 2 28 f SW LCOUT (5) Where IOUTMAX is the maximum output current, KRIPPLE is the ripple factor, RESR is the ESR of the output capacitor, fSW is the switching frequency, L is the inductor value, and COUT is the output capacitance. In the case of ceramic output capacitors, RESR is very small and does not contribute to the ripple. Therefore, a lower capacitance value can be used for ceramic type. In the case of tantalum or electrolytic capacitors, the ripple is dominated by RESR multiplied by the ripple current. In that case, the output capacitor is chosen to have sufficiently low ESR. Where VIN is the input voltage, VOUT is the output voltage, fSW is the switching frequency, ILOADMAX is the maximum load current, and KRIPPLE is the ripple factor. Typically, choose KRIPPLE = 30% to correspond to the peak-to-peak ripple current being 30% of the maximum load current. ILPK _ PK = VIN For ceramic output capacitor, typically choose a capacitance of about 22µF. For tantalum or electrolytic capacitors, choose a capacitor with less than 50mΩ ESR. An 330µF or 470µF electrolytic capacitor is recommended. (2) The peak inductor current is estimated as: Rectifier Schottky Diode 1 ILPK = ILOADMAX + ILPK _ PK (3) 2 The selected inductor should not saturate at ILPK. The maximum output current is calculated as: LLIM is the internal current limit. Use a Schottky diode as the rectifier to conduct current when the High-Side Power Switch is off. The Schottky diode must have current rating higher than the maximum output current and a reverse voltage rating higher than the maximum input voltage. Further more, the low forward voltage Schottky is preferable for high efficiency and smoothly operation. Input Capacitor Current Sense Resistor The input capacitor needs to be carefully selected to maintain sufficiently low ripple at the supply input of the converter. A low ESR capacitor is highly recommended. Since large current flows in and out of this capacitor during switching, its ESR also affects efficiency. The traces leading to and from the sense resistor can be significant error sources. With small value sense resistors, trace resistance shared with the load can cause significant errors. It is recommended to connect the sense resistor pads directly to the CSP and CSN pins using “Kelvin” or “4-wire” connection techniques as shown below. IOUTMAX = ILIM _ 1 I _ 2 LPK PK (4) The input capacitance needs to be higher than 10µF. The best choice is the ceramic type. However, low ESR tantalum or electrolytic types may also be used provided that the RMS ripple current rating is higher than 50% of the output current. The input capacitor should be placed close to the IN and GND pins of the IC, with the shortest traces possible. In the case of tantalum or electrolytic types, a ceramic capacitor is recommended to parallel with tantalum or electrolytic capacitor, which should be placed right next to the IC. Innovative PowerTM PCB Load Trace Kevin Sense Traces -7- Sense Resistor www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 APPLICATIONS INFORMATION PC Board Layout Guidance When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the IC. 1) Arrange the power components to reduce the AC loop size consisting of CIN, VIN pin, SW pin and the Schottky diode. 2) Place input decoupling ceramic capacitor CIN as close to VIN pin as possible. C IN is connected power GND with vias or short and wide path. 3) Use “Kelvin” or “4-wire” connection techniques from the sense resistor pads directly to the CSP and CSN1, CSN2 pins. 4) Use copper plane and thermal vias for GND for best heat dissipation and noise immunity. 5) Use short trace connecting HSB-CHSB-SW loop. 6) SW pad is noise node switching from VIN to GND. It should be isolated away from the rest of circuit for good EMI and low noise operation. Innovative PowerTM -8- www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 Typical Application Circuit for 5V/3.4A Car Charger CSN2 4.5V to 40V C1 47μF IN C2 10μF CSN1 U1 ACT4525 GND DP C3 22nF HSB SW L1 33μH CSP DM Rcs2 50mΩ D1 SK54L C4 C5 10μF 470μF Rcs1 25mΩ C6 2.2μF 5.1V/2.4A Vout 5.1V/1A Vout D- C7 2.2μF D- D+ D+ GND GND BOM List for 5V/3.4A Car Charger ITEM REFERENCE DESCRIPTION MANUFACTURER QTY 1 U1 IC, ACT4525, SOP-8EP Active-Semi 1 2 C1 Capacitor, Electrolytic, 47µF/35V Murata, TDK 1 3 C2 Capacitor, Ceramic, 10µF/25V, 1206, SMD Murata, TDK 1 4 C3 Capacitor, Ceramic, 22nF/25V, 0603, SMD Murata, TDK 1 5 C4 Capacitor, Ceramic, 10µF/10V, 1206, SMD Murata, TDK 1 6 C5 Capacitor, Electrolytic, 470µF/10V Murata, TDK 1 7 C6,C7 Capacitor, Ceramic, 2.2µF/10V, 0805, SMD Murata, TDK 2 8 L1 Inductor, 33µH, 4.5A, 20%, 9 D1 Diode, Schottky, 40V/5A, SK54L Panjit 1 10 Rcs1 Chip Resistor, 25mΩ, 1206, 1/2W, 1% SART 1 11 Rcs2 Chip Resistor, 50mΩ, 1206, 1/2W, 1% SART 1 Innovative PowerTM 1 -9- www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 TYPICAL PERFORMANCE CHARACTERISTICS (Schematic as show in typical application circuit, Ta = 25°C, unless otherwise specified) Output1 CC/CV Curve Efficiency vs. Load current 5.0 Output Voltage (V) Efficiency (%) 90 85 VIN =24V 80 ACT4525-002 VIN =12V 95 6.0 ACT4525-001 100 75 70 65 VIN =24V 4.0 VIN =12V 3.0 2.0 1.0 60 0 500 1000 1500 2000 2500 3000 0 3500 0 500 Load Current (mA) 1500 2000 2500 3000 Output Current (mA) Output Over Voltage (5V Vout) Start up into CC Mode ACT4525-004 ACT4525-003 CH1 1000 CH1 VOUT = 5.1V RLORD = 1.5Ω IOUT = 2.65A VIN = 12V CH2 CH2 CH3 CH1: VIN, 10V/div CH2: VOUT, 2V/div CH3: IOUT, 2A/div TIME: 400µs/div CH1: VOUT, 1V/div CH2: SW, 10V/div TIME: 1ms/div Load Transient (80mA-1A-80mA) Vin=12V, Vout=5V Load Transient (1A-2.4A-1A) Vin=12V, Vout=5V CH2 ACT4525-006 ACT4525-005 CH1 CH1 CH2 CH1: VOUT, 100mV/div CH2: IOUT, 1A/div TIME: 400us//div Innovative PowerTM CH1: VOUT, 200mV/div CH2: IOUT, 1A/div TIME: 400us//div - 10 - www.active-semi.com Copyright © 2015 Active-Semi, Inc. ACT4525 Rev1.1, December 17th, 2015 PACKAGE OUTLINE SOP-8EP PACKAGE OUTLINE AND DIMENSIONS E b e D D1 SYMBOL E2 A1 E1 A2 A L θ c DIMENSION IN MILLIMETERS DIMENSION IN INCHES MIN MAX MIN MAX A 1.350 1.727 0.053 0.068 A1 0.000 0.152 0.000 0.006 A2 1.350 1.550 0.053 0.061 b 0.330 0.510 0.013 0.020 c 0.170 0.250 0.007 0.010 D 4.700 5.100 0.185 0.200 D1 3.202 3.402 0.126 0.134 E 3.734 4.000 0.147 0.157 E1 5.800 6.200 0.228 0.244 E2 2.313 2.513 0.091 0.099 e 1.270 TYP 0.050 TYP L 0.400 1.270 0.016 0.050 θ 0° 8° 0° 8° Active-Semi, Inc. reserves the right to modify the circuitry or specifications without notice. Users should evaluate each product to make sure that it is suitable for their applications. Active-Semi products are not intended or authorized for use as critical components in life-support devices or systems. Active-Semi, Inc. does not assume any liability arising out of the use of any product or circuit described in this datasheet, nor does it convey any patent license. Active-Semi and its logo are trademarks of Active-Semi, Inc. For more information on this and other products, contact [email protected] or visit http://www.active-semi.com. ® is a registered trademark of Active-Semi. Innovative PowerTM - 11 - www.active-semi.com Copyright © 2015 Active-Semi, Inc.