Fujitsu MB39A104 manual ESR ≤ ΠfC L 033 364

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MB39A104

CH2	ΔVO
ESR ≤	ΔVO		−				1
ESR ≤	ΔIL		−			2πfCL
≤	0.033				−				1
≤	0.364				−		2π ⋅ 500		⋅ 103	⋅ 82 ⋅ 10−6
	0.364						2π ⋅ 500		⋅ 103	⋅ 82 ⋅ 10−6

≤86.8 mΩ

Capacitance value

	CH1	ΔIL
	CL ≥	ΔIL
	CL ≥	2πf (ΔVO − ΔIL ⋅ ESR)
	≥	0.491
	≥	2π ⋅ 500 ⋅ 103 ⋅ (0.050 − 0.491 ⋅ 0.05)

≥6.14 ∝F

	CH2	ΔIL
	CL ≥
		2πf (ΔVO − ΔIL ⋅ ESR)
	≥	0.364
		2π ⋅ 500 ⋅ 103 ⋅ (0.033 − 0.364 ⋅ 0.05)

≥7.83 ∝F

Ripple current
CH1
ICLrms ≥	(VIN − VO) ton


			2√3L
			2√3L
≥			(19 − 5) ⋅ 0.263

			⋅ 15 ⋅ 10−6 ⋅ 500 ⋅ 103
	2√3		⋅ 15 ⋅ 10−6 ⋅ 500 ⋅ 103

≥141.7 mArms

CH2

ICLrms ≥		(VIN − VO) ton


			2√3L
			2√3L
≥				(19 − 3.3)				⋅ 0.174

				⋅ 15 ⋅ 10−6				⋅ 500 ⋅ 103
		2√3		⋅ 15 ⋅ 10−6				⋅ 500 ⋅ 103

≥105.1 mArms

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Image 31

Contents Description FeaturesPackage PIN Assignments MB39A104PIN Description Pin No Symbol DescriptionsBlock Diagram Recommended Operating Conditions Parameter Symbol Condition Rating Unit Min MaxParameter Symbol Condition Value Unit Min Typ Absolute Maximum RatingsMin Typ Max Electrical CharacteristicsParameter Pin No ConditionsPin No Conditions Value Unit Min Parameter SymbolReference Voltage vs. Ambient Temperature Typical CharacteristicsTriangular Wave Oscillation Frequency Power Dissipation vs. Ambient Temperature Functions Operating circuit Timer-latch overcurrent protection circuit block OCPUnder voltage lockout protection circuit Uvlo Protection circuit operating function tableSetting the Triangular Oscillation Frequency Setting the Output VoltageSetting the SOFT-START and Discharge Times MB39A104 Without Setting Soft-Start Time Treatment Without Using CS TerminalOvercurrent detection circuit About TIMER-LATCH Protection CircuitMethod to detect by mean current Overcurrent Protection Circuit Range of OperationTimer-latch short-circuit protection circuit Resetting the Latch of Each Protection Circuit Treatment Without Using Cscp TerminalEquivalent Circuit On Power on OFF Standby mode Component Specification Vendor Parts ListCH1 Selection of ComponentsCH2 = 3 2 ⋅ 0.05 ⋅ 0.174 = 0.078 W Example Peak-to-peak value ΔIL Di ≥ I O ⋅ 1 − ESR ≤ ΠfC L 050 491 ESR ≤ ΠfC L 033 364 Total Efficiency vs. Input Voltage Reference DataSwitching Wave Form CH1 Part number Package Remarks Usage PrecautionOrdering Information Do not apply negative voltagesIndex Package DimensionsFujitsu Limited