SC2608BSTRT

SC2608B Simple, Synchronous Voltage Mode PWM Controller POWER MANAGEMENT Draft Description Features +5V or +12V input voltage The SC2608B is a versatile voltage-mode PWM control- ler designed for use in step down DC/DC power supply 250kHz operation applications. A simple, fixed frequency, highly efficient High efficiency (>90%) buck regulator can be implemented using the SC2608B 1.25% Voltage feedback accuracy over tempera- with minimal external components. The input voltage ture range is from +5V to +12V. Internal level shift and drive Hiccup mode over current protection circuitry eliminates the need for an expensive P-channel, 1.2A output drive high-side MOSFET. The small device footprint allows for R Current sensing for protection DS(ON) compact circuit design. Industrial temperature range Available in SO-8 and SO-8 EDP package SC2608B features include temperature compensated Integrated boot strap diode voltage reference, triangle wave oscillator, current limit Thermal Shut down comparator, and an externally compensated error ampli- fier. Current limit is implemented by sensing the voltage Fully WEEE and RoHS Compliant drop across the bottom MOSFET R . DS(ON) Applications The SC2608B operates at a fixed frequency of 250kHz providing an optimum compromise between efficiency , Termination supplies external component size, and cost. Low cost microprocessor supplies Peripheral card supplies SC2608B has a thermal protection circuit, which is Industrial power supplies O activated if the junction temperature exceeds 150 C. High density DC/DC conversion Typical Application Circuit Figure 1 1 Revision 4: Jan. 2007 www.semtech.comSC2608B POWER MANAGEMENT Absolute Maximum Ratings Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters specified in the Electrical Characteristics section is not implied. PrPPPPraaaaarrrrraaaaammmmmeeeeettttteeeeerrr SSSlSlSmyyyyymmmmmbbbbbooooolll MmMMMsMmaaaaaxxxxxiiiiimmmmmuuuuumm UsUUUUsnnnnniiiiitttttss V to GND +V20 CC BST to PHASE +V15 BST to GND +V20 (note1) PHASE to GND -V1 to +24 (note1) DH to PHASE +V15 (note2) DL to GND -V1 to +15 COMP/SS to GND +V7 SENSE to GND +V7 O Thermal Resistance Junction to Case (SO-8) 40 C/W JC O Thermal Resistance Junction to Case (SOIC - 8L EDP) 5.5 C/W JC O Thermal Resistance Junction to Ambient (SO-8) 120 C/W JA O Thermal Resistance Junction to Case (SOIC - 8L EDP) 36.5 C/W JA O Operating Temperature Range T -40 to +125 C J O STtorage Temperature Range -65 to +150 C STG ESD Rating (Human Body Model) E4SD kV Note 1: Under pulsing condition, the peak negative voltage can not be lower than -3.6V with less than 20nS from 50% to 50%. Note 2: Under pulsing condition, the peak negative voltage can not be lower than -5V with less than 20nS from 50% to 50%. Electrical Characteristics o Unless specified: V = 12V, V - V = 12 V, V = 3.3V, T = T = 25 C. CC BST Phase OUT J A PPPrPrPlaaaaarrrrraaaaammmmmeeeeettttteeeeerrr SlSSSsSlyyyyymmmmmbbbbboooooll CsCCCsCnooooonnnnndddddiiiiitttttiiiiiooooonnnnnss MnMMMpMniiiiinn TTTpTxTpyyyyypp MMMxMxMsaaaaaxx UUUsUUsnnnnniiiiitttttss PPPyPyPooooowwwwweeeeerrrrr SSSSSuuuuupppppppppplllllyyy SVupply Voltage 441V CC SIupply Current V<60.4V 6A.5 m CC COMP UtUUUUtnnnnndddddeeeeerrrrr vvvvvooooollllltttttaaaaagggggeeeee LLLLLoooooccccckkkkkooooouuuuuttt O UVVLO Threshold 0< T < 85C535.7 3V.8 th J HVysteresis 8V0 m hys EEErErErrrrrrrrrrooooorrrrr AAAAAmmmmmpppppllllliiiiifffffiiiiieeeeerrr FVeedback Voltage 4.5V<Vcc<5.5V 07.78707.79 0V.80 FB O O 0 C < T < 85 C A 10.8V<Vcc<13.2V 08.7901. 0V.8 O O 0 C < T < 85 C A 2 www.semtech.com 2007 Semtech Corp.