MS1003SH datasheet(32/41 Pages) SHINDENGEN

32 / 41 page

MS1003SH･MS1004SH

Application Note Ver.2.2

SHINDENGEN ELECTRIC MFG. CO. , LTD

32/41

5.5.5 Design of Vcc pin

(1) Basic circuit

The diagram to the right is the basic circuit. The circuit

consists of D103 and C109 for rectifying the Nc coil

output and C110 for noise reduction between Vcc and

GND.

For C110, use a capacitor with good frequency

characteristics. Design around 0.22 μF.

(2) Measure  against poorly regulated Vcc voltage

If the Vcc voltage is not well regulated due to design conditions, such as the load specification, add R110

as shown below to the left. This is generally the most cost-effective way to improve regulation. The chart

to the right shows model lines of Vcc voltage regulation relative to output power. The red line represents

Vcc voltage regulation with the basic circuit (1). The measure adjusts behavior to the black line.

(3) Measure  against poorly regulated Vcc voltage

The diagram below shows a circuit that improves regulation more effectively than measure (2).

Previous Vcc

regulation

OVP voltage

Improved Vcc

regulation

Output power

MS1003SH Datasheet(PDF) 32 Page - Shindengen Electric Mfg.Co.Ltd