SC4508ABUCK-BOOSTEVB SEMTECH [Semtech Corporation], SC4508ABUCK-BOOSTEVB Datasheet
SC4508ABUCK-BOOSTEVB
Related parts for SC4508ABUCK-BOOSTEVB
SC4508ABUCK-BOOSTEVB Summary of contents
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POWER MANAGEMENT Description The SC4508A is a low voltage current mode switching regulator controller that drives a P-channel power MOSFET with programmable switching frequency. It can be configured in either buck or buck boost (inverting) con- verters. The converters can ...
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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 ...
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POWER MANAGEMENT Electrical Characteristics (Cont.) Unless specified 12V FB+ REF FB ...
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POWER MANAGEMENT Pin Configuration TOP VIEW VDD OSC COMP OUT SS/ VREF NC AGND (MLPQ - 12, 4mm x 4mm) Pin Descriptions ...
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POWER MANAGEMENT Block Diagram Marking Information Top View yyww = Date Code (Example: 0012) 2007 Semtech Corp. 5 SC4508A www.semtech.com ...
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POWER MANAGEMENT Application Information The SC4508A is designed to control buck (step down) or buck-boost (inverting) converter with P-channel MOSFET as a switch using current mode, programmable switching frequency architecture. During steady state operation, the switch is turned on each ...
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POWER MANAGEMENT Application Information (Cont for Buck Boost I - full load current output voltage O V ...
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POWER MANAGEMENT Application Information (Cont.) core losses (flux swing) and the winding AC resistance losses are higher. A compromise is to choose the inductance such that peak-to-peak inductor ripple- current is 20% to 30% of the rated output load current ...
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POWER MANAGEMENT Application Information (Cont.) When determining the ESR value, both the steady state ripple-voltage and the dynamic load transient need to be considered. To keep the steady state output ripple-voltage < the ESR should satisfy ...
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POWER MANAGEMENT Application Information (Cont.) Req and Ceq are both functions of frequency. For rigorous design, the equivalent ESR should be evaluated at the ripple frequency for voltage ripple calculation when both ceramic and electrolytic capacitors are used ...
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POWER MANAGEMENT Application Information (Cont 100 Rds ( ) , Cg 200 Rds ( ) 500 Rds ( ) Rds On-resistance (mOhm) FOM:100*10^{-12} FOM:200*10^{-12} FOM:500*10^{-12} Figure 5. ...
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POWER MANAGEMENT Application Information (Cont gsp Only a portion of the total losses ( the MOSFET package. Here Qg is the total gate charge specified in the ...
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POWER MANAGEMENT Application Information (Cont ssr When calculated as 2.5ms. Note that µ SS ssr2 during this period, the converter does not start switching ...
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POWER MANAGEMENT Application Information (Cont.) The inner current-loop is unstable (sub-harmonic oscillation) unless the inductor current up-slope is steeper than the inductor current down-slope. For stable operation above 50% duty-cycle, a compensation ramp is added to the sensed-current. In the ...
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POWER MANAGEMENT Application Information (Cont.) assumptions, the controller parameters are determined as follows and oesr ...
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POWER MANAGEMENT Application Information (Cont.) where, the single dominant pole is Figure 9. A simple model of buck-boost converter with current mode control. and the zero due to the output capacitor ...
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POWER MANAGEMENT Application Information (Cont use Since S < further calculated that:: zRHP ...
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POWER MANAGEMENT Evaluation Board Schematic, Buck 12V GND U1 U1 SC4508A 1nF C4 1uF 12 2 VDD SS/EN OUT OSC VREF 0.1uF FB+ 330pF 6 8 AGND FB- f s=470KHz ...
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POWER MANAGEMENT Evaluation Board Schematic, Buck-Boost 12V GND U1 SC4508A C4 1uF 12 VDD 3 SS/ OSC 0.1uF 680pF 6 AGND f s=250KHz 7 PGND Bill of Materials ...
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POWER MANAGEMENT Typical Characteristics Buck Converter Sartup Buck Converter Sartup Buck Converter Sartup Buck Converter Sartup Buck Converter Sartup 50mS/DIV a: OUTPUT VOLTAGE, 5V/DIV b: SS/EN PIN VOLTAGE, 5V/DIV C: INDUCTOR CURRENT, 2A/DIV D: VREF PIN VOLTAGE, 0.5V/DIV Buck CCM ...
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POWER MANAGEMENT Outline Drawing - MLPQ-12 PIN 1 INDICATOR (LASER MARK) A aaa C E1 NOTES: 1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES). 2. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. ...