ETA1036V50S2F

ETA1036 3W, 0.85V Startup Voltage, Synchronous Step-Up Converter with RealShutdown and Short-Circuit Protection in SOT23-5 DESCRIPTION FEATURES The ETA1036 is a high efficiency synchronous step-up converter that can provide up to 3W of power to a boosted output from a low voltage source. Unlike most step-up converter, not only it starts up at a very low input voltage as low as 0.85V, it also incorporates circuits that disconnect the input from output, during shutdown, short-circuit, output current overloading, or other events when output is higher than the input. This eliminates the need for an external MOSFET and its control circuitry to disconnect the input from output, and provides robust output overload protection. The ETA1036 starts up from a voltage as low as 0.85V making it ideal for applications with single-cell or two-cell alkaline, NiCd, and NiMh batteries. A switching frequency of 2MHz minimizes solution footprint by allowing the use of tiny and low profile inductors and ceramic capacitors. An internal synchronous MOSFET provides highest efficiency and with a current mode control that is internally compensated, external parts count is reduced to minimal. ETA1036 is available in three output voltage options. They are 2.1V, 3.3V and 5V. It is housed in a tiny SOT23-5 package. Output Disconnect Short-circuit Protection 3W Output Power Output to Input Reversed Current Protection 0.85V Low Start-up Voltage VIN range from 0.6V to 4.5V Up to 96% Efficiency 40μA No load IQ and light load PFM Mode Internal Synchronous Rectifier Current Mode control Logic Control Shutdown and Thermal shutdown SOT23-5 Package             APPLICATIONS USB OTG for MIDs, Smartphones Mobile back-up Battery Chargers Alkaline, NiCd, and NiMh batteries applications USB powered devices     ORDERING INFORMATION PART # ETA1036V50S2F ETA1036V33S2F ETA1036V21S2F TYPICAL APPLICATION 4 3 SW OUT 1 EN 80% 5 IN 4.7μF 2.2nF *Needed if Vout=5V TOP MARK CPYW DzYW DaYW Efficiency Vs IOUT 100% 2.2μH Output Voltage 5.0V 3.3V 2.1V ETA1036 GND 2 6.3V 22μF 60% ŋ VOUT 2.1,3.3V, 5V 40% VIN=3V VIN=2.4V VIN=1.8V VIN=1.2V 20% 0% VOUT=3.3V 0.01 0.1 1 IOUT (A) Outperform with Efficiency www.ETAsolution.com Proprietary Information DO NOT Distribute 1 ETA1036 PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS (Note: Exceeding these limits may damage the device. Exposure to absolute maximum rating conditions for long periods may affect device reliability.) OUT 1 GND 2 5 SW SW/OUT Voltage........................................................-0.3V to 5.5V All Other PIN Voltages……………………………..–0.3V to V IN SW to ground current ………….…….……….......Internally limited Operating Temperature Range ……................…–40°C to 85°C Storage Temperature Range ………………..….–55°C to 150°C ETA1036 EN 3 4 IN Thermal Resistance SOT23-5 θJA θJC SOT23-5……………………………………………..220…….…110 ........oC/W ELECTRICAL CHACRACTERISTICS (VIN = 1.8V, VOUT = 3.3V, unless otherwise specified. Typical values are at TA = 25 oC.) PARAMETER Minimum Input Voltage Startup Voltage CONDITIONS Output Voltage VIN =1.8 Quiescent Current at IN Shutdown Supply Current at IN Switching Frequency Maximum Duty Cycle NMOS Switch On Resistance PMOS Switch On Resistance NMOS Switch Current Limit Start-up Current Limit Output to Input Reverse Leakage Current SW Leakage Current EN Input Current EN Input Low Voltage EN Input High Voltage Thermal Shutdown No Switching VEN=GND VINVOUT) Operation The ETA1036 will continue to supply the output voltage even when the input voltage exceeds the output voltage. Since the PMOS no longer acts as a low-impedance switch in this mode, power dissipation increases within the IC to cause a sharp drop in efficiency. Limit the maximum output current to maintain an acceptable junction temperature. BLOCK DIAGRAM EN OUT IN UVLO & Thermal shutdown REF + EA + COMP network Σ - - PWM Logic SW DRIVER OSC Slope Comp GND Outperform with Efficiency www.ETAsolution.com Proprietary Information DO NOT Distribute 5 ETA1036 5V APPLICATIONS For ETA1036-50, the 5V output voltage option, in order to maintain an acceptable peak voltage at SW, a small parallel capacitor snubber between SW and OUT is necessary, and an output cap of greater than 44μF is also required as shown in below figure. VIN 3.6V 6.8μH 4 5 IN SW 2.2nF VOUT, 5V 4.7μF 3 OUT 1 EN ETA1036-50 6.3V 22μF x2 GND 2 PCB LAYOUT ETA1036’s pin-out is perfectly designed to have peripheral passive devices laid closest to the IC to achieve the best performance. One should always keep Cout (22uF x 2) and Csw (2.2nF) as close to the ETA1036 as possible. A PCB layout is shown below for reference, for only one layer of PCB wiring needed. Outperform with Efficiency www.ETAsolution.com Proprietary Information DO NOT Distribute 6 ETA1036 PACKAGE OUTLINE Outperform with Efficiency www.ETAsolution.com Proprietary Information DO NOT Distribute 7