SY8113GADC

Application Notes: AN_SY8113G High Efficiency, 500kHz, 3A, 18V Input Synchronous Step Down Regulator General Description Features The SY8113G is a high efficiency 500 kHz synchronous step-down DC-DC converter capable of delivering 3A current. The SY8113G operates over a wide input voltage range from 4.5V to 18V and integrates main switch and synchronous switch with very low RDS(ON) to minimize the conduction loss.  SY8113G always operates under continuous condition mode, low output ripple and small inductor and capacitor size are achieved with 500kHz switching frequency.     Ordering Information M TC fo r d Applications SY8113 □(□□)□      ia Note -- Set Top Box Portable TV Access Point Router DSL Modem LCD TV on f id en t Package type TSOT23-6 l-P Temperature Code Package Code Optional Spec Code Ordering Number SY8113GADC re re pa     low RDS(ON) for internal switches (top/bottom): 80mΩ/40mΩ 4.5-18V input voltage range 3A output current capability 500 kHz switching frequency Instant PWM architecture to achieve fast transient responses. Cycle-by-cycle peak current limitation Internal softstart limits the inrush current ±1.5% 0.6V reference TSOT23-6 package Co rp .C Typical Applications Efficiency vs. Load Current 100 90 C1 IN Si ON/ OFF VOUT LX y le rg CIN L1 R1 SY8113G C4 COUT Efficiency (%) BS VIN 80 70 60 50 40 30 EN FB VIN=5V,VOUT=3.3V VIN=12V,VOUT=3.3V VIN=18V,VOUT=3.3V 20 GND 10 R2 0 0.001 0.01 0.1 1 Load Current (A) Figure 1. Schematic Diagram AN_SY8113G Rev.0.9A © 2018 Silergy Corp. Figure2. Efficiency vs. Load Current Silergy Corp. Confidential-prepared for Customer Use Only 1 All Rights Reserved. SY8113G BS LX GND IN FB M TC Pinout (top view) EN fo r TSOT23-6 Top Mark: Itxyz, (Device code: It, x=year code, y=week code, z= lot number code) Pin Number 1 Pin Description Boot-Strap Pin. Supply high side gate driver. Decouple this pin to LX pin with 0.1uF ceramic cap. Ground pin GND 2 FB 3 EN 4 Output Feedback Pin. Connect this pin to the center point of the output resistor divider (as shown in Figure 1) to program the output voltage: Vout=0.6*(1+R1/R2) Enable control. Pull high to turn on. Do not float. IN LX 5 6 Input pin. Decouple this pin to GND pin with at least 1uF ceramic cap Inductor pin. Connect this pin to the switching node of inductor id en t ia l-P re pa re d Pin Name BS on f Absolute Maximum Ratings (Note 1) Si le rg y Co rp .C Supply Input Voltage --------------------------------------------------------------------------------------------------------- 19V Enable Voltage-------------------------------------------------------------------------------------------------------- VIN + 0.3V FB Voltage ---------------------------------------------------------------------------------------------------------------------- 4V Power Dissipation, PD @ TA = 25°C, TSOT23-6 ---------------------------------------------------------------------- 1.5W Package Thermal Resistance (Note 2) θ JA ----------------------------------------------------------------------------------------------------------------- 66°C /W θ JC ----------------------------------------------------------------------------------------------------------------- 15°C /W Junction Temperature Range -------------------------------------------------------------------------------------------- 150°C Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------------- 260°C Storage Temperature Range ----------------------------------------------------------------------------------- -65°C to 150°C Recommended Operating Conditions (Note 3) Supply Input Voltage ---------------------------------------------------------------------------------------------- 4.5V to 18V Junction Temperature Range --------------------------------------------------------------------------------- -40°C to 125°C Ambient Temperature Range ---------------------------------------------------------------------------------- -40°C to 85°C AN_SY8113G Rev.0.9A © 2018 Silergy Corp. Silergy Corp. Confidential-prepared for Customer Use Only 2 All Rights Reserved. SY8113G Electrical Characteristics (VIN = 12V, VOUT = 1.2V, L = 2.2uH, COUT = 47uF, TA = 25°C, IOUT = 1A unless otherwise specified) Test Conditions IFB RDS(ON)1 RDS(ON)2 ILIM,TOP VFB=3.3V Min 4.5 Max 18 10 0.609 Unit V µA V 5.8 50 90 50 6.6 nA mΩ mΩ A 4 5.2 A EN=0 0.591 -50 Typ 5 0.6 M TC Symbol VIN ISHDN VREF fo r 80 40 re d ILIM 1.5 ia l-P re pa VENH VENL VUVLO VHYS id en t tSS TSD THYS 3.8 40 140 4.2 0.3 60 170 500 800 150 0.4 4.5 100 220 15 V V V V ns ns kHz uS °C °C on f Parameter Input Voltage Range Shutdown Current Feedback Reference Voltage FB Input Current Top FET RON Bottom FET RON Top FET Peak Current Limit Bottom FET Valley Current Limit EN Rising Threshold EN Falling Threshold Input UVLO Threshold UVLO Hysteresis Min ON Time Min OFF Time Switching Frequency Soft-start Time Thermal Shutdown Temperature Thermal Shutdown Hysteresis θ JA is measured in the natural convection at T A = 25°C on a two-layer Silergy Evaluation Board. le rg y Note 2: Co rp .C Note 1: Stresses beyond the “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only. Functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Si Note 3: The device is not guaranteed to function outside its operating conditions AN_SY8113G Rev.0.9A © 2018 Silergy Corp. Silergy Corp. Confidential-prepared for Customer Use Only 3 All Rights Reserved. SY8113G Block Diagram IN M TC Current Sense BS 1.5V 0.6V l-P FB re EN Current Sense id en t ia Internal SST LX re pa PWM Control & Protect Logic d fo r Input UVLO 4.5V Internal Power GND Si le rg y Co rp .C on f Thermal Protection AN_SY8113G Rev.0.9A © 2018 Silergy Corp. Silergy Corp. Confidential-prepared for Customer Use Only 4 All Rights Reserved. SY8113G Typical Performance Characteristics Efficiency vs. Load Current 90 80 80 70 70 Efficiency (%) 100 90 60 50 40 50 40 30 VIN=5V,VOUT=1.2V VIN=12V,VOUT=1.2V VIN=18V,VOUT=1.2V 20 10 fo r 30 60 20 10 0 0 0.01 0.1 1 0.001 0.01 re 0.001 d Efficiency (%) 100 M TC Efficiency vs. Load Current re pa Load Current (A) Efficiency vs. Load Current VIN=5V,VOUT=3.3V VIN=12V,VOUT=3.3V VIN=18V,VOUT=3.3V 0.1 1 Load Current (A) Output Ripple (VIN=12V, VOUT=3.3V, IOUT=0A) l-P 100 90 ΔVOUT 10mV/div VLX 10V/div IL 1A/div ia 70 60 id en t Efficiency (%) 80 50 40 30 on f VIN=7.4V,VOUT=5V VIN=12V,VOUT=5V VIN=18V,VOUT=5V 20 10 0.001 .C 0 0.01 0.1 Time (2μs/div) Co rp Load Current (A) 1 Output Ripple Si le rg y (VIN=12V, VOUT=3.3V, IOUT=3A) ΔVOUT 20mV/div VLX 10V/div IL 2A/div Time (2μs/div) AN_SY8113G Rev.0.9A © 2018 Silergy Corp. Silergy Corp. Confidential-prepared for Customer Use Only 5 All Rights Reserved. SY8113G Load Transient Load Transient (VIN=12V, VOUT=3.3V, IOUT=0 -1.5A) (VIN=12V, VOUT=3.3V, IOUT=0.3 -3A) 1A/div IL 200mV/div 2A/div re d fo r IL ΔVOUT 100mV/div M TC ΔVOUT Time (200μs/div) re pa Time (200μs/div) Startup from VIN 10V/div VIN 10V/div 2V/div 10V/div IL 2A/div .C VLX VOUT 2V/div VLX 10V/div IL 2A/div on f VOUT id en t ia VIN Shutdown from VIN (VIN=12V, VOUT=3.3V, IOUT=3A) l-P (VIN=12V, VOUT=3.3V, IOUT=3A) Co rp Time (2ms/div) Time (2ms/div) Shutdown from Enable (VIN=12V, VOUT=3.3V, IOUT=3A) Si le rg y Startup from Enable (VIN=12V, VOUT=3.3V, IOUT=3A) EN 5V/div VOUT EN 5V/div 2V/div VOUT 2V/div VLX 10V/div VLX 10V/div IL 2A/div IL 2A/div Time (800μs/div) AN_SY8113G Rev.0.9A © 2018 Silergy Corp. Time (800μs/div) Silergy Corp. Confidential-prepared for Customer Use Only 6 All Rights Reserved. SY8113G Short Circuit Protection Short Circuit Protection (VIN=12V, VOUT=3.3V, 0A to Short) (VIN=12V, VOUT=3.3V, 3A to Short) VLX 10V/div IL 2A/div VLX 2V/div 10V/div M TC VOUT 2V/div fo r VOUT 2A/div re d IL Time (4ms/div) Si le rg y Co rp .C on f id en t ia l-P re pa Time (4ms/div) AN_SY8113G Rev.0.9A © 2018 Silergy Corp. Silergy Corp. Confidential-prepared for Customer Use Only 7 All Rights Reserved. SY8113G 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 10uF low ESR ceramic capacitor is recommended. Operation The SY8113G is a high efficiency 500 kHz synchronous step-down DC-DC converter capable of delivering 3A current. The SY8113G operates over a wide input voltage range from 4.5V to 18V and integrates main switch and synchronous switch with very low RDS(ON) to minimize the conduction loss. M TC 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 22uF capacitance. d fo r SY8113G always operates under continuous condition mode, low output ripple and small inductor and capacitor size are achieved with 500kHz switching frequency. on f re pa id en t ia l-P Applications Information Because of the high integration in the SY8113G 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. 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: V (1  VOUT /VIN, MAX ) L  OUT FSW  IOUT, MAX  40% re SY8113G provides protection functions such as cycle by cycle current limiting and thermal shutdown protection. SY8113G will sense the output voltage conditions for the fault protection. Feedback resistor dividers R1 and R2: Co rp .C 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 10kΩ and 1MΩ is highly recommended for both resistors. If Vout is 3.3V, R1=100k is chosen, then using following equation, R2 can be calculated to be 22.1k: The SY8113G 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. VOUT(1-VOUT/VIN,MAX) ISAT, MIN  IOUT, MAX  2  FSW  L VOUT y le rg Si 0.6V R2  R1 . VOUT  0.6V where Fsw is the switching frequency and I OUT,MAX is the maximum load current. 0.6VFB GND R1 R2 Input capacitor CIN: The ripple current through input capacitor is calculated as： 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