Fujitsu MB3887 manual Block Diagram

MB3887

■BLOCK DIAGRAM

−INE1	8
OUTC1 10		<Current Amp1>	<Error Amp1>
+INC1 13		+	VREF
			−
		⋅ 20
−INC1	12	−	+				21 VCC (O)
+INE1	9
			<PWM Comp.><OUT>
FB1 7				+
				+
				+		Drive	20 OUT
−INE2	4			−
OUTC2	2	<Current Amp2>	<Error Amp2>	VCC
			VREF
+INC2 24		+
			−
		⋅ 20					19 VH
−INC2	1	−	+	Bias
				Voltage	(VCC − 6 V)
+INE2	3			<VH>
				2.5 V
FB2	5			1.5 V
			<Error Amp3>	<UVLO>		VCC
			VREF
−INE3 16			−	(VCC UVLO)		215 kΩ
			+		+
OUTD 11			+			35 kΩ
			4.2 V		−
					0.91 V
					(0.77 V)
FB3 15		<SOFT>			VREF
					UVLO
		VREF
		10
		∝A				VCC
CS 22				4.2 V			18 VCC
			<OSC>	<REF>		<CTL>	14 CTL
			45 pF		VREF
				bias	5.0 V
			17	6		23
			RT	VREF		GND

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