Epson S1F70000 EPSON, S1F76640 Series, Configuration Example of High Magnification Step-upCircuit with Diode

S1F76640 Series

Configuration Example of High Magnification Step-up Circuit with Diode

S1F76640, if an external diode is attached, can realize 5 times or more step-up operation and voltage stabilized output. Since the forward voltage drop VF of the diode makes the output impedance of the step-up output higher, it is recommended to use a diode of small VF. Figure 8.10 shows a configuration example of a circuit with 2 diodes, which realizes 6 times step-up operation and voltage stabilized output. Make the wire between VO and VRI as short as possible. Figure 8.11 shows the potential relations diagram

By the way, use the voltage applied to the VRI pin below the absolute maximum rated voltage.

	1	RV	VRI 16
	2	VREG	VO 15
VSS or VO	3	TC1	CAP3+ 14		+
VSS or VO	4		CAP2+ 13	+	– C4
		TC2			+
	5	POFF	CAP2– 12	–C2	–C5	+
					+	– C6
	6	VSS	CAP1+ 11	+	– C3
	7	OSC1	CAP1– 10	– C1
	8	OSC2	VDD 9

Figure 8.10 Configuration Example of 6 times step-up Circuit with Diode

2 · VF

VO'

VO

4 · VI 6 · V1 6 · VI –2 · VF

VDD

VI

VSS

Figure 8.11 Potential Relations Diagram of 6 times Step-up Circuit with Diode

S1F76640 Series

S1F70000 Series Technical Manual

EPSON 2–63