DIO54302TST6

Rev 1.0 DIO54302 High-Efficiency 3A, 28V Input Synchronous Step Down Converter Features Descriptions Low RDS(ON) for internal switches (top/bottom) The DIO54302 is high-efficiency, high frequency 80mΩ/40mΩ, 3.0A synchronous step-down DC-DC regulator ICs  4.5-28V input voltage range capable of delivering up to 3A output currents.  High-Efficiency Synchronous-Mode The DIO54302 family operate over a wide input  Internal soft start limits the inrush current voltage range from 4.5V to 28V and integrate main  Over Current protection switch and synchronous switch with very low   Output short circuit protection with hiccup RDS(ON) to minimize the conduction loss.  Thermal shutdown The COT architecture with Pseudo fixed switching  Available in TSOT23-6 package frequency operation provides fast transient response and eases loop stabilization. DIO54302 operates in pulse skip mode, which maintains high efficiency during light load operation. Protection features include over-current protection and thermal shutdown. The DIO54302 requires a minimal number of readily-available, standard, external components and is available in a space-saving TSOT23-6 package. Applications  Portable Navigation Device  Set Top Box  Portable TV  LCD TV Function Block VIN Internal Power Input UVLO Current Sense Bootst rap Regulator EN PWM Control & Protect Logic BS SW FB Thermal Protection GND Ordering Information Order Part Number DIO54302TST6 www.dioo.com Top Marking W402 TA Green -40 to 85°C Package TSOT23-6 Tape & Reel, 3000 © 2019 DIOO MICROCIRCUITS CO., LTD DIO54302• V1.0 DIO54302 GND 1 6 BS SW 2 5 EN VIN 3 4 FB 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=0.6*(1+R1/R2).Add optional C2 (10pF~47pF) to speed up the transient response. EN This pin is the enable pin. Float the EN pin to enable. 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. © 2019 DIOO MICROCIRCUITS CO., LTD DIO54302• V1.0 High-Efficiency 3A, 28V Input Synchronous Step Down Converter Pin Assignments DIO54302 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 maximum rating conditions for extended periods may affect device reliability. Parameter Rating Unit -0.3 to 32 V -0.3 to VIN+0.3 V FB Voltage -0.3 to 6 V BS Voltage -0.3 to SW+6 V -5 to 32 V Supply Voltage (V+ – V-) EN, SW Voltage SW (15ns transient) Voltage ӨJA 87.9 ӨJC 42.2 Package Thermal Resistance °C/W Storage Temperature Range -65 to 150 °C Junction Temperature Range 150 °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 Supply Voltage 4.5 to 28 V Junction Temperature Range -40 to 125 °C Ambient Temperature Range -40 to 85 °C www.dioo.com © 2019 DIOO MICROCIRCUITS CO., LTD DIO54302• V1.0 High-Efficiency 3A, 28V Input Synchronous Step Down Converter Absolute Maximum Ratings DIO54302 VIN = 12V, VOUT = 1.2V, L = 2.2μH, COUT = 47μF, 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 28 V 140 0.588 VFB=3.3V Max µA 5 10 µA 0.6 0.612 V 50 nA -50 RDS(ON) Top FET RON 80 mΩ RDS(ON) Bottom FET RON 40 mΩ 4.0 A ILIM Low side power FET current limit VENH EN Rising Threshold VENL EN Falling Threshold VUVLO fSW 3.0 1.21 1.1 1.28 1.19 VIN Under-Voltage Unlock V 4.45 Threshold, Rising V V Switching Frequency 500 kHz Min ON Time 40 ns Min OFF Time 180 ns TSS Soft Start Time 1 ms TSD Thermal Shutdown Temperature 148 °C THYS Thermal Shutdown Hysteresis 20 °C Specifications subject to change without notice. www.dioo.com © 2019 DIOO MICROCIRCUITS CO., LTD DIO54302• V1.0 High-Efficiency 3A, 28V Input Synchronous Step Down Converter Electrical Characteristics DIO54302 C1 100nF L1 4.7μH VIN 4.5-28V VIN VOUT 3.3V BS SW CIN 10μF R1 100K EN GND COUT1 COUT2 22μF 22μF (OPTION) FB ON/ OFF C2 22pF R2 22.1K Typical Performance Characteristics www.dioo.com Start up from VIN Shut down from VIN (VIN=12V,VOUT=3.3V,Load=1Ω) (VIN=12V,VOUT=3.3V,Load=1Ω) © 2019 DIOO MICROCIRCUITS CO., LTD DIO54302• V1.0 High-Efficiency 3A, 28V Input Synchronous Step Down Converter Typical Application DIO54302 Shut down from Enable (VIN=12V,VOUT=3.3V,Load=1Ω) (VIN=12V,VOUT=3.3V,Load=1Ω) Load transient Load transient (VIN=12V,VOUT=3.3V,Load=0.3-3A) Ripple (VIN=12V,VOUT=3.3V,Load=0A) www.dioo.com (VIN=12V,VOUT=3.3V,Load=1.5-3A) Ripple (VIN=12V,VOUT=3.3V,Load=3A) © 2019 DIOO MICROCIRCUITS CO., LTD DIO54302• V1.0 High-Efficiency 3A, 28V Input Synchronous Step Down Converter Start up from Enable DIO54302 Short Circuit Recovery (VIN=12V,VOUT=3.3V,Load=3A) (VIN=12V,VOUT=3.3V,Load=3A) Application Information DIO54302 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. Because of the high integration in the DIO54302 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=100k is chosen, then R2 can be calculated to be 22.1k. R2= 0.6V R1 VOUT − 0.6V VOUT R1 0.6FB R2 GND www.dioo.com © 2019 DIOO MICROCIRCUITS CO., LTD DIO54302• V1.0 High-Efficiency 3A, 28V Input Synchronous Step Down Converter Short Circuit Protection DIO54302 This ripple current through input capacitor is calculated as: ICIN_RMS=IOUT ⋅ D(1 − D) This formula has a maximum at VIN=2VOUT condition, where ICIN_RMS=IOUT/2. This simple worst-case condition is commonly used for DC/DC design. 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 10μF low ESR ceramic capacitor is recommended. Output capacitor COUT 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 DIO54302 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