DIO6920TST6

Rev 1.1 DIO6920 High-Efficiency 2A, 24V Input Synchronous Step Down Converter Features Descriptions Low RDS(ON) for internal switches (top/bottom) The DIO6920 is high-efficiency, high frequency 120mΩ/75mΩ, 2.0A synchronous step-down DC-DC regulator ICs 4.5-24V input voltage range capable of delivering up to 2A output currents. High-Efficiency Synchronous-Mode The DIO6920 family operate over a wide input Internal soft start limits the inrush current voltage range from 4.5V to 24V and integrate main Over Current protection switch and synchronous switch with very low Thermal shutdown RDS(ON) to minimize the conduction loss. Green package: DIO6920 adopts the COT architecture to achieve TSOT23 -6 is pin compatible fast transient responses for high step down applications and high efficiency at light loads. In addition, it operates at pseudo-constant frequency of 500kHz under heavy load conditions to minimize the size of inductor and capacitor. Applications Function Block Portable Navigation Device Set Top Box Portable TV LCD TV Ordering Information Order Part Number DIO6920TST6 www.dioo.com Top Marking 20YW TA Green -40 to +85°C Package TSOT23-6 Tape & Reel, 3000 © 2018 DIOO MICROCIRCUITS CO., LTD DIO6920• Rev. 1.1 DIO6920 TSOT23-6 Figure 1 Pin Assignment (Top View) Pin Definitions Pin Name GND Description Power Ground SW Inductor pin. Connect this pin to the switching node of inductor. VIN Power Input Output Feedback Pin. Connect this pin to the center point of the output resistor divider FB (as shown in Figure 1) to program the output voltage: VOUT=0.765*(1+R1/R2).Add optional C2 (10pF~47pF) to speed up the transient response. EN Enable control. Pull high to turn on. Do not float. Bootstrap. Connect a capacitor and a resistor between SW and BS pins to form a floating supply BS www.dioo.com across the high-side switch driver. Recommend to use 0.1µF BS capacitor. © 2018 DIOO MICROCIRCUITS CO., LTD DIO6920• Rev. 1.1 High-Efficiency 2A, 24V Input Synchronous Step Down Converter Pin Assignments DIO6920 Stresses beyond those listed under “Absolute Maximum Rating” may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maxim rating conditions for extended periods may affect device reliability. Parameter Rating Unit 28 V VIN+0.3 V FB Voltage 6 V BS Voltage SW+6 V Supply Voltage ( V+ – V-) EN, SW Voltage ӨJA 89 ӨJC 44.5 Package Thermal Resistance °C/W Storage Temperature Range -65 to 150 °C Junction Temperature Range 125 °C Lead Temperature Range 260 °C Recommend Operating Conditions The Recommended Operating Conditions table defines the conditions for actual device operation. Recommended Operating conditions are specified to ensure optimal performance to the datasheet specifications. DIOO does not Recommend exceeding them or designing to Absolute Maximum Ratings. Parameter Rating Unit 4.5 to 24 V Junction Temperature Range -40 to 125 °C Ambient Temperature Range -40 to 85 °C Supply Voltage www.dioo.com © 2018 DIOO MICROCIRCUITS CO., LTD DIO6920• Rev. 1.1 High-Efficiency 2A, 24V Input Synchronous Step Down Converter Absolute Maximum Ratings DIO6920 VIN = 12V, VOUT = 1.2V, L = 2.2µH, COUT = 22µF, TA = 25°C, IOUT=1A unless otherwise specified. Symbol Parameter Test Conditions VIN Input Voltage Range IQ Quiescent Current IOUT=0, VFB=VREF ⋅ 105% ISHDN Shutdown Current EN=0 VREF Feedback Reference Voltage IFB FB Input Current Min Typ 4.5 Unit 24 V 140 0.758 VFB=VIN Max µA 5 10 µA 0.765 0.772 V 50 nA -50 RDS(ON) Top FET RON 120 mΩ RDS(ON) Bottom FET RON 75 mΩ ILIM Bottom FET Valley Current Limit 2 A 1.5 V VENH EN Rising Threshold VENL EN Falling Threshold 0.4 V VUVLO Input UVLO Threshold 4.5 V fSW Switching Frequency 500 kHz TON ON Time 200 ns Min ON Time 50 ns Min OFF Time 100 ns TSS Soft Start Time 1 ms TSD Thermal Shutdown Temperature 150 °C THYS Thermal Shutdown Hysteresis 15 °C VIN = 12V, VOUT = 1.2V, IOUT=1A Specifications subject to change without notice. www.dioo.com © 2018 DIOO MICROCIRCUITS CO., LTD DIO6920• Rev. 1.1 High-Efficiency 2A, 24V Input Synchronous Step Down Converter Electrical Characteristics DIO6920 Typical Performance Characteristics Start up from Enable Shut down from Enable (VIN=12V,VOUT=3.3V,Load=1.5Ω) (VIN=12V,VOUT=3.3V,Load=1.5Ω) Load Transient (VIN=12V,VOUT=3.3V,Load=0.2-2A) www.dioo.com Load Transient (VIN=12V,VOUT=3.3V,Load=1-2A) © 2018 DIOO MICROCIRCUITS CO., LTD DIO6920• Rev. 1.1 High-Efficiency 2A, 24V Input Synchronous Step Down Converter Typical Application DIO6920 Ripple (VIN=12V,VOUT=3.3V,Load=2A) Short Circuit Protection Short Circuit Recovery (VIN=12V,VOUT=3.3V,Load=2A) www.dioo.com (VIN=12V,VOUT=3.3V,Load=2A) © 2018 DIOO MICROCIRCUITS CO., LTD DIO6920• Rev. 1.1 High-Efficiency 2A, 24V Input Synchronous Step Down Converter Ripple (VIN=12V,VOUT=3.3V,Load=0A) DIO6920 DIO6920 is a synchronous buck regulator IC that integrates the COT control, top and bottom switches on the same die to minimize the switching transition loss and conduction loss. With ultra low RDS(ON) power switches and proprietary COT control, this regulator IC can achieve the highest efficiency and the highest switch frequency simultaneously to minimize the external inductor and capacitor size, and thus achieving the minimum solution footprint. DIO6920 provides protection functions such as cycle by cycle current limiting and thermal shutdown protection. DIO6920 will sense the output voltage conditions for the fault protection. Applications Information Because of the high integration in the DIO6920 IC, the application circuit based on this regulator IC is rather simple. Only input capacitor CIN, output capacitor COUT, output inductor L and feedback resistors (R1 and R2) need to be selected for the targeted applications specifications. Feedback resistor dividers R1 and R2 Choose R1 and R2 to program the proper output voltage. To minimize the power consumption under light loads, it is desirable to choose large resistance values for both R1 and R2. A value of between 10k and 1M is highly recommended for both resistors. If VOUT is 3.3V, R1=40.2k is chosen, then R2 can be calculated to be 12k. R2= 0.765V R1 VOUT − 0.765V Input capacitor CIN This ripple current through input capacitor is calculated as: ICIN_RMS=IOUT ⋅ D(1 − D) To minimize the potential noise problem, place a typical X5R or better grade ceramic capacitor really close to the IN and GND pins. Care should be taken to minimize the loop area formed by CIN, and IN/GND pins. In this case, a 4.7µF low ESR ceramic capacitor is recommended. www.dioo.com © 2018 DIOO MICROCIRCUITS CO., LTD DIO6920• Rev. 1.1 High-Efficiency 2A, 24V Input Synchronous Step Down Converter Operation DIO6920 The output capacitor is selected to handle the output ripple noise requirements. Both steady state ripple and transient requirements must be taken into consideration when selecting this capacitor. For the best performance, it is recommended to use X5R or better grade ceramic capacitor greater than 22µF capacitance. Output inductor L There are several considerations in choosing this inductor. 1) Choose the inductance to provide the desired ripple current. It is suggested to choose the ripple current to be about 40% of the maximum output current. The inductance is calculated as: L= VOUT (1 − VOUT / VIN , MAX ) FSW × IOUT , MAX × 40% where Fsw is the switching frequency and IOUT,MAX is the maximum load current. The DIO6920 regulator IC is quite tolerant of different ripple current amplitude. Consequently, the final choice of inductance can be slightly off the calculation value without significantly impacting the performance. 2) The saturation current rating of the inductor must be selected to be greater than the peak inductor current under full load conditions. ISAT,MIN>IOUT,MAX + VOUT (1 − VOUT / VIN , MAX ) 2 ⋅ FSW ⋅ L 3) The DCR of the inductor and the core loss at the switching frequency must be low enough to achieve the desired efficiency requirement. It is desirable to choose an inductor with DCR