Application Note: SY98081/A/B/C/D/E/F High Efficiency 3MHz, 0.6A Inductor Built-in Synchronous Step Down Regulator Preliminary Specification General Description SY98081/A/B/C/D/E/F are 3MHz, 0.6A synchronous step-down converters which integrates an inductor and a control IC in one tiny package (2.0mm×1.5mm, H=1.26mm). It can operate over a wide input voltage range from 2.5V to 5.5V and integrate main switch and synchronous switch with very low RDS (ON) to minimize the conduction loss. Features • Low RDS(ON) for internal switches (top/bottom) 230mΩ/150mΩ • Integrate an inductor to minimizes the external components and PCB layout design • 2.5~5.5V input voltage range • Output voltage: ﹣ SY98081: Output voltage adjustable ﹣ SY98081A: Fixed 1.2VOUT ﹣ SY98081B: Fixed 1.5VOUT ﹣ SY98081C: Fixed 1.8VOUT ﹣ SY98081D: Fixed 2.5VOUT ﹣ SY98081E: Fixed 3.3VOUT ﹣ SY98081F: Fixed 1.0VOUT • High switching frequency 3MHz minimizes the external components • Internal soft-start limits the inrush current • 100% dropout operation • RoHS Compliant and Halogen Free • Output auto discharge function • Compact package: QFN2x1.5-8 Ordering Information SY98081□(□□)□Temperature CodePackage Code Optional Spec Code Temperature Range: -40°C to 85°C Applications • • • • • Mobile phone, Smart phone Bluetooth Headsets WiMAX PDA, MID, UMPC Portable game console Digital camera, CamcordeTypical Applications AN_SY98081/A/B/C/D/E/F Rev. 0.4 Silergy Corp. Confidential- Prepared for Customer Use Only 1 enta-PrepaSergyCorpConfdredforSMI SY98081/A/B/C/D/E/F AN_SY98081/A/B/C/D/E/F Rev. 0.4 Silergy Corp. Confidential- Prepared for Customer Use Only 2 enta-PrepaSergyCorpConfdredforSMI SY98081/A/B/C/D/E/F Pinout (Top View) OUT EN GND 1 2 3, 7 Output Pin. Decouple this pin to ground with at least 4.7uF ceramic cap. Enable control. Pull high to turn on. Do not float. SY98081 FB 4 SY98081A/B/C/D/E/F LX IN 5,6 8 fidenBuilt-in inductor node. Leave it floating. Supply Input Voltage, LX, OUT pins -------------------------------------------------------------------------------------- 6.0V Enable, FB Voltage---------------------------------------------------------------------------------------------------- VIN + 0.6V Power Dissipation, PD @ TA = 25°C, QFN2×1.5-8 --------------------------------------------------------------------------------------------------------- TBD Package Thermal Resistance (Note 2) θJA ------------------------------------------------------------------------------------------------------------------- TBD θJC --------------------------------------------------------------------------------------------------------------------TBD Junction Temperature Range ----------------------------------------------------------------------------------------------150°C Lead Temperature (Soldering, 10 sec.) ---------------------------------------------------------------------------------- 260°C Storage Temperature Range ----------------------------------------------------------------------------------- -65°C to 150°C Sil AN_SY98081/A/B/C/D/E/F Rev. 0.4 Silergy Corp. Confidential- Prepared for Customer Use Only 3 ergy C Absolute Maximum Ratings (Note 1) orp. CInput pin. Decouple this pin to GND pin with at least 4.7uF ceramic cap. ontialGround pin. -PrOutput adjustable version. Connect this pin to the center point of the output resistor divider to program the output voltage: VOUT=0.6×(1+R1/R2). Fixed output version. Connect this pin to the output for the output voltage regulation. epaTop Mark: YGxyz for SY98081 (device code: YG, x=year code, y=week code, z= lot number code) UMxyz for SY98081A (device code: UM, x=year code, y=week code, z= lot number code) UNxyz for SY98081B (device code: UN, x=year code, y=week code, z= lot number code) TPxyz for SY98081C (device code: TP, x=year code, y=week code, z= lot number code) UOxyz for SY98081D (device code: UO, x=year code, y=week code, z= lot number code) UPxyz for SY98081E (device code: UP, x=year code, y=week code, z= lot number code) UQxyz for SY98081F (device code: UQ, x=year code, y=week code, z= lot number code) Pin Pin Number Pin Description Name red for SMI SY98081/A/B/C/D/E/F Recommended Operating Conditions (Note 3) Supply Input Voltage ----------------------------------------------------------------------------------------------- 2.5V to 5.5V Junction Temperature Range ----------------------------------------------------------------------------------- -40°C to 125°C Ambient Temperature Range ------------------------------------------------------------------------------------ -40°C to 85°C Electrical Characteristics (VIN = 5V, VOUT = 1.8V, COUT = 4.7uF, TA = 25°C, unless otherwise specified) 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. Note 2: θJA is measured in the natural convection at TA = 25°C on a four-layer Silergy Evaluation Board. Note 3: The device is not guaranteed to function outside its operating conditions. Silergy Corp.NFET RON Inductance PFET Current Limit EN rising threshold EN falling threshold Input UVLO threshold UVLO hysteresis Oscillator Frequency Min ON Time Max Duty Cycle Soft Start Time Thermal Shutdown Temperature Thermal Shutdown Hysteresis Output discharge resistor RDS(ON),N L ILIM VENH VENL VUVLO VHYS FOSC TSS TSD THYS RDSC epaPFET RON RDS(ON),P red for SM 1.3 1.5 100 Parameter Input Voltage Range Quiescent Current Shutdown Current Feedback Reference Voltage Output Voltage Symbol VIN IQ ISHDN VREF VOUT Test Conditions IOUT=0, VFB=VREF⋅105% EN=0 SY98081 SY98081A SY98081B SY98081C SY98081D SY98081E SY98081F Min 2.5 0.588 1.176 1.47 1.764 2.45 3.234 0.98 Typ 40 0.1 0.6 1.2 1.5 1.8 2.5 3.3 1.0 230 150 1.0 0.1 3 65 1 150 15 120 Max 5.5 1 0.612 1.224 1.53 1.836 2.55 3.366 1.02 0.4 2.5 Unit V µA µA V V V V V V V mΩ mΩ uH A V V V V MHz ns % ms °C °C Ω Confiden AN_SY98081/A/B/C/D/E/F Rev. 0.4 Silergy Corp. Confidential- Prepared for Customer Use Only 4 tial-Pr I SY98081/A/B/C/D/E/F Typical Performance Characteristics (SY98081C) Efficiency vs. Load Current
AN_SY98081/A/B/C/D/E/F Rev. 0.4 Silergy Corp. Confidential- Prepared for Customer Use Only 5 enta-PrepaSergyCorpConfdredforSMI SY98081/A/B/C/D/E/F Short Circuit Protection
(VIN=5.0V, VOUT=1.8V, 0A to Short)
Short Circuit Protection
(VIN=5.0V, VOUT=1.8V, 0.6A to Short)
VOUT 1V/divIL 0.5A/div
VOUT 1V/div
IL 0.5A/div
Time (2ms/div)
Load Transient
(VIN=5.0V, VOUT=1.8V, ILOAD=0.06-0.6A)
VOUT(AC) 200mV/div
IL 0.5A/div
Time (40µs/div)
on SilAN_SY98081/A/B/C/D/E/F Rev. 0.4 Silergy Corp. Confidential- Prepared for Customer Use Only 6 ergy Corp. Cfidential -Prepared fo r SMTime (2ms/div)
I SY98081/A/B/C/D/E/F Operation SY98081/A/B/C/D/E/F are 3MHz, 0.6A synchronous step-down converters which integrates an inductor and a control IC in one tiny package (2.0mm×1.5mm, H=1.2mm). It can operate over a wide input voltage range from 2.5V to 5.5V and integrate main switch and synchronous switch with very low RDS (ON) to minimize the conduction loss. fidenBecause of the high integration in SY98081/A/B/C/D/E/F, the application circuit based on this regulator IC is rather simple. Only input capacitor CIN and output capacitor COUT need to be selected for the targeted application specifications. Input capacitor CIN: A typical X7R or better grade ceramic capacitor and greater than 4.7uF capacitance is recommended. To minimize the potential noise problem, place this 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. 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 Silergy Corp. Contial-Pr epared for SM AN_SY98081/A/B/C/D/E/F Rev. 0.4 Silergy Corp. Confidential- Prepared for Customer Use Only 7 I Applications Information when selecting this capacitor. For the best performance, it is recommended to use X7R or better grade ceramic capacitor with 6V rating and greater than 4.7uF capacitance. Layout Design: For the minimum noise problems, we should place the following components close to the IC: CIN and COUT. 1) It is desirable to maximize the PCB copper area connecting to GND pin to achieve the best thermal and noise performance. If the board space allowed, a ground plane is highly desirable. 2) CIN must be close to IN and GND pins. The loop area formed by CIN and GND must be minimized. 3) Connect the LX pins together to reduce the inductor DCR. It is strongly recommended to reduce the LX routing area to avoid the potential noise problem. 4) The trace connecting to the FB pin must NOT be adjacent to the LX node on the PCB layout to minimize the noise coupling to FB pin. Load Transient Considerations: SY98081/A/B/C/D/E/F integrate the compensation components to achieve good stability and fast transient response. SY98081/A/B/C/D/E/F QFN2x1.5-8 FC Package Outline Drawing y Corp. ConfidenSil Side View Notes: erg All dimension in MM and exclude mold flash & metal burr AN_SY98081/A/B/C/D/E/F Rev. 0.4 Silergy Corp. Confidential- Prepared for Customer Use Only 8 tial -Pr epaTop View Bottom View re d for SMI