SCT2430STER

SILICON CONTENT TECHNOLOGY SCT2430 Rev.1.3 3.8V-40V Vin, 3.5A, High Efficiency Synchronous Step-down DCDC Converter with Programmable Frequency FEATURES DESCRIPTION • • • • The SCT2430 is 3.5A synchronous buck converters with wide input voltage, ranging from 3.8V to 40V, which integrates an 80mΩ high-side MOSFET and a 50mΩ low-side MOSFET. The SCT2430, adopting the peak current mode control, supports the Pulse Skipping Modulation (PSM) with typical 25uA low quiescent current which assists the converter on achieving high efficiency at light load or standby condition. Wide Input Range: 3.8V-40V Up to 3.5A Continuous Output Current 0.8V ±1% Feedback Reference Voltage Integrated 80mΩ High-Side and 50mΩ Low-Side Power MOSFETs Pulse Skipping Mode (PSM) with 25uA Quiescent Current in Sleep Mode 100ns Minimum On-time 2ms Internal Soft-start Time Adjustable Frequency 100KHz to 2.2MHz External Clock Synchronization Frequency Spread Spectrum (FSS) Modulation for EMI Reduction Precision Enable Threshold for Programmable Input Voltage Under-voltage Lock Out Protection (UVLO) Threshold and Hysteresis Low Dropout Mode Operation Derivable Inverting Voltage Regulator Over-voltage and Over-Temperature Protection Available in an ESOP-8 Package • • • • • • • • • • • APPLICATIONS • Battery Pack Powered System - Cordless Power Tools, Cordless Home Appliance, Drone, Aero Modeling, GPS Tracker etc. Cigarette Lighter Adapters, Chargers LCD Display USB Type-C Power Delivery, USB Charging Industrial and Medical Distributed Power Supplies Optical Communication and Networking System Automotive System • • • • • • The SCT2430 features programmable switching frequency from 100 kHz to 2.2MHz with an external resistor, which provides the flexibility to optimize either efficiency or external component size. The converter supports external clock synchronization with a frequency band from 100kHz to 2.2MHz. The SCT2430 allows power conversion from high input voltage to low output voltage with a minimum 100ns on-time of highside MOSFET. The SCT2430 is an Electromagnetic Interference (EMI) friendly buck converter with implementing optimized design for EMI reduction. The SCT2430 features Frequency Spread Spectrum FSS with ±6% jittering span of the switching frequency and modulation rate 1/512 of switching frequency to reduce the conducted EMI. The SCT2430 offers cycle-by-cycle current limit and hiccup over current protection, thermal shutdown protection, output over-voltage protection and input voltage under-voltage protection. The device is available in an 8-pin thermally enhanced SOP-8 package. TYPICAL APPLICATION BOOT VIN SW RT/CLK R4 FB VOUT C5 VIN GND SCT2430 EN COMP C1 C2 100 L1 R1 R3 C4 R2 90 Efficiency(%) C3 80 70 VIN=24V,VOUT=3.3V VIN=24V,VOUT=5V VIN=12V,VOUT=5V VIN=12V,VOUT=3.3V 60 50 40 1 For more information www.silicontent.com 10 100 Output Current(mA) 1000 10000 © 2017 Silicon Content Technology Co., Ltd. All Rights Reserved Product Folder Links: SCT2430 1 SCT2430 REVISION HISTORY NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Revision 1.0: Released to Market Revision 1.1: Updated Description Revision 1.2: Updated Table 3 Revision 1.3: Updated Figure 1. SCT2430 Design Example and Table 3: Compensation Values DEVICE ORDER INFORMATION PART NUMBER PACKAGE MARKING PACKAGE DISCRIPTION SCT2430STE 2430 8-Lead Plastic ESOP For Tape & Reel, Add Suffix R (e.g. SCT2430STER) 1) ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION Over operating free-air temperature unless otherwise noted(1) DESCRIPTION MIN MAX UNIT VIN, EN -0.3 42 V BOOT -0.3 46 V SW -0.3 42 V BOOT-SW -0.3 6 V COMP, FB, RT/CLK -0.3 6 V Operating junction temperature TJ(2) -40 150 °C Storage temperature TSTG -65 150 °C (1) (2) BOOT 1 VIN 2 EN 3 RT/CLK 4 Thermal PAD 9 8 SW 7 GND 6 COMP 5 FB Figure 2. 8-Lead Plastic E-SOP Stresses beyond those listed under Absolute Maximum Rating may cause device permanent damage. The device is not guaranteed to function outside of its Recommended Operation Conditions. The IC includes over temperature protection to protect the device during overload conditions. Junction temperature will exceed 150°C when over temperature protection is active. Continuous operation above the specified maximum operating junction temperature will reduce lifetime. PIN FUNCTIONS NAME NO. BOOT 1 VIN 2 EN 3 RT/CLK 4 2 PIN FUNCTION Power supply bias for high-side power MOSFET gate driver. Connect a 0.1uF capacitor from BOOT pin to SW pin. Bootstrap capacitor is charged when low-side power MOSFET is on or SW voltage is low. Input supply voltage. Connect a local bypass capacitor from VIN pin to GND pin. Path from VIN pin to high frequency bypass capacitor and GND must be as short as possible. Enable pin to the regulator with internal pull-up current source. Pull below 1.1V to disable the converter. Float or connect to VIN to enable the converter. The tap of resistor divider from VIN to GND connecting EN pin can adjust the input voltage lockout threshold. Set the internal oscillator clock frequency or synchronize to an external clock. Connect a resistor from this pin to ground to set switching frequency. An external clock can be input directly to the RT/CLK pin. The internal oscillator synchronizes to the external clock frequency with PLL. If detected clocking edges stops, the operation mode automatically returns to resistor programmed frequency. For more information www.silicontent.com © 2017 Silicon Content Technology Co., Ltd. All Rights Reserved Product Folder Links: SCT2430 SCT2430 FB 5 COMP 6 Inverting input of the trans-conductance error amplifier. The tap of external feedback resistor divider from the output to GND sets the output voltage. The device regulates FB voltage to the internal reference value of 0.8V typical. Error amplifier output. Connect to frequency loop compensation network. GND 7 Ground SW Thermal Pad 8 Regulator switching output. Connect SW to an external power inductor Heat dissipation path of die. Electrically connection to GND pin. Must be connected to ground plane on PCB for proper operation and optimized thermal performance. 9 RECOMMENDED OPERATING CONDITIONS Over operating free-air temperature range unless otherwise noted PARAMETER DEFINITION VIN VOUT TJ Input voltage range Output voltage range Operating junction temperature MIN MAX UNIT 3.8 0.8 -40 40 40 125 V V °C MIN MAX UNIT -2 +2 kV -0.5 +0.5 kV ESD RATINGS PARAMETER DEFINITION Human Body Model(HBM), per ANSI-JEDEC-JS-001-2014 specification, all pins(1) Charged Device Model(CDM), per ANSI-JEDEC-JS-0022014 specification, all pins(2) VESD (1) JEDEC document JEP155 states that 500V HBM allows safe manufacturing with a standard ESD control process. (2) JEDEC document JEP157 states that 250V CDM allows safe manufacturing with a standard ESD control process. THERMAL INFORMATION PARAMETER RθJA RθJC THERMAL METRIC SOP-8L Junction to ambient thermal resistance(1) Junction to case thermal UNIT 42 resistance(1) °C/W 45.8 (1) SCT provides RθJA and RθJC numbers only as reference to estimate junction temperatures of the devices. RθJA and RθJC are not a characteristic of package itself, but of many other system level characteristics such as the design and layout of the printed circuit board (PCB) on which the SCT2430 is mounted, thermal pad size, and external environmental factors. The PCB board is a heat sink that is soldered to the leads and thermal pad of the SCT2430. Changing the design or configuration of the PCB board changes the efficiency of the heat sink and therefore the actual RθJA and RθJC. ELECTRICAL CHARACTERISTICS VIN=24V, TJ=-40°C~125°C, typical value is tested under 25°C. SYMBOL PARAMETER TEST CONDITION Power Supply VIN Operating input voltage VIN_UVLO ISHDN MIN TYP 3.8 Input UVLO Threshold Hysteresis Shutdown current from VIN pin VIN rising EN=0, no load For more information www.silicontent.com 3.5 400 1 MAX 40 V 3.7 V mV μA 3 © 2017 Silicon Content Technology Co., Ltd. All Rights Reserved Product Folder Links: SCT2430 UNIT 3 SCT2430 IQ Quiescent current from VIN pin Power MOSFETs RDSON_H High-side MOSFET on-resistance RDSON_L EN floating, no load, nonswitching, BOOT-SW=5V 25 μA VBOOT-VSW=5V 80 mΩ 50 mΩ Low-side MOSFET on-resistance Reference and Control Loop VREF Reference voltage of FB 0.792 0.8 0.808 V GEA Error amplifier trans-conductance -2μA