SC4508A Buck or Buck-Boost (Inverting) Current Mode Controller POWER MANAGEMENT Features Description The SC4508A is a low voltage current mode switching Wide input voltage range 2.7V to 15V regulator controller that drives a P-channel power Programmable output voltage MOSFET with programmable switching frequency. It can Programmable switching frequency up to 1.5MHz be configured in either buck or buck boost (inverting) con- Buck or buck boost (inverting) configuration verters. The converters can be operated from 2.7V to Current mode control with slope compensation 15V input voltage range. The typical operating supply Very low quiescent current in shutdown mode current is 3mA and a shutdown pin allows the user to Accessible reference voltage turn the controller off reducing it to less than 200A. Hiccup mode after 32 cycle-by-cycle OCP The output voltage can adjusted by external resistor di- 4mm x 4mm MLPQ-12 lead free package. This vider. The switching frequency is programmable up to product is fully WEEE and RoHS compliant 1.5MHz, allowing small inductor and capacitor values to minimize PCB space. The operating current level is pro- Applications grammable via an external sense resistor. Accessible ref- erence voltage allows users to make output voltage as Low power point of use converters low as they want. Single or multiple output low power converters Positive and/or negative output voltage DSL cards Graphic cards I/O cards Negative bias supplies Typical Application Circuits Vin Vin V+ V+ VREF VREF FB+ CS SC4508A FB- CS FB+ SC4508A OUT FB- COMP OUT COMP Vout Vout SS/EN GND OSC SS/EN GND OSC 1 www.semtech.com Revision: July 25, 2007SC4508A POWER MANAGEMENT Absolute Maximum Rating 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. Plarameter Smymbo Msaximu Unit VDD to GND -V0.3 to 16 (1) SS/EN to GND 3V.2 FB+, FB-, COMP, OSC to GND 5V VREF Current 1Am Thermal Resistance, Junction to Ambient 4W8 C/ JA Thermal Resistance, Junction to Case 3WC/ JC STtorage Temperature Range -C60 to +150 STG JTunction Temperature Range -C40 to +150 J PTeak IR Reflow Temperature 10 - 40s 2C60 PKG Note: (1) Voltage from internal circuitry could be higher than 3.2V. See Application Information, Soft-Start section. Electrical Characteristics Unless specified: V = 12V, V = V , V = 0, OUT = open, C = 1uF, C = 0.1uF, C = 330pF. T = T = -40C to 125C DD FB+ REF FB- VDD SS/EN OSC A J Psarameter TnestCondition Mpi Txy Mta Uni PowerSupply Input Voltage Range 25.7 1V Qwuiescent Current S0S/EN = lo 200 5A0 Odperating CurrentS3S/EN = high, No loa mA Undervoltage Lockout SVtart Threshold r5ising 25.3 25. 2V.5 DD UVLO Hysteresis 1V00 m Oscillator Frequency Range 1000 1z50 KH Frequency 4050 500 5z5 KH Charge Current 1A00 ErrorAmplifier Feedback Input Voltage -70.2 0V. Offset Voltage 2Vm Input Bias Current 1000 3A0 n Transconductance 5Sm Output Source or Sink Current 5001A0 www.semtech.com 2007 Semtech Corp. 2