Fujitsu MB39A104 manual Block Diagram

Page 4

MB39A104

■BLOCK DIAGRAM

−INE1	10	VREF		Error	L priority		CH1	1	VCCO
		VREF			PWM

	10 ∝A		−	Amp1
CS1 11			+		+ Comp.1		Drive1
			+		+		Drive1
			+		+	Pch		3	OUT1
		1.24 V			−	Pch		3	OUT1
		1.24 V	L priority
			L priority
FB1	9					IO = 200 mA
						IO = 200 mA
						at VCCO	= 12 V
						Current	−	4	VS1
						Current		4	VS1
						Protection	+	5	ILIM1
						Logic		5	ILIM1
						Logic
DTC1	6
−INE2	15	VREF		Error	L priority		CH2
		VREF		Error
	10 ∝A		−	Amp2	PWM
CS2 14			+		+ Comp.2		Drive2
CS2 14			+		+	Pch		22 OUT2
		1.24 V			−	Pch		22 OUT2
		1.24 V	L priority
			L priority
FB2 16						IO = 200 mA
						IO = 200 mA
DTC2 19						at VCCO	= 12 V
						Current	−	21	VS2
		H: at SCP	H priority			Current		21	VS2
		H: at SCP	H priority			Protection	+	20	ILIM2
			SCP			Protection	+	20	ILIM2
			SCP			Logic
			Comp.			Logic
			Comp.
				+
				+
				−
				(3.1 V)		H: at OCP	VCC − 5 V	2	VH
							VCC − 5 V
							VH
							VH
		SCP					Bias
		Logic					Voltage
CSCP	8				2.5 V			23 GNDO
					2.5 V	Error Amp Power Supply
		UVLO			1.5 V	Error Amp Power Supply
					1.5 V

			H:UVLO			Error Amp Reference		7	VCC
			H:UVLO
			release
			release		bias	1.24 V
					bias	1.24 V	Power
		OSC					Power	24 CTL
		OSC			Accuracy	VREF	VR1 ON/OFF	24 CTL
					Accuracy		CTL
					±1%		CTL
					±1%
					5.0 V
		12	13		17		18
		RT CT			VREF		GND

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Image 4

Contents Description FeaturesPackage MB39A104 PIN AssignmentsPin No Symbol Descriptions PIN DescriptionBlock Diagram Parameter Symbol Condition Rating Unit Min Max Parameter Symbol Condition Value Unit Min TypAbsolute Maximum Ratings Recommended Operating ConditionsElectrical Characteristics ParameterPin No Conditions Min Typ MaxParameter Symbol Pin No Conditions Value Unit MinTypical Characteristics Reference Voltage vs. Ambient TemperatureTriangular Wave Oscillation Frequency Power Dissipation vs. Ambient Temperature Functions Timer-latch overcurrent protection circuit block OCP Under voltage lockout protection circuit UvloProtection circuit operating function table Operating circuitSetting the Output Voltage Setting the Triangular Oscillation FrequencySetting the SOFT-START and Discharge Times MB39A104 Treatment Without Using CS Terminal Without Setting Soft-Start TimeAbout TIMER-LATCH Protection Circuit Overcurrent detection circuitOvercurrent Protection Circuit Range of Operation Method to detect by mean currentTimer-latch short-circuit protection circuit Treatment Without Using Cscp Terminal Resetting the Latch of Each Protection CircuitEquivalent Circuit On Power on OFF Standby mode Parts List Component Specification VendorSelection of Components CH1CH2 = 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 Reference Data Total Efficiency vs. Input VoltageSwitching Wave Form CH1 Usage Precaution Ordering InformationDo not apply negative voltages Part number Package RemarksPackage Dimensions IndexFujitsu Limited