MS1003SH･MS1004SH

Application Note Ver.2.2

SHINDENGEN ELECTRIC MFG. CO. , LTD

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1. Overview

1.1 Introduction

We have developed the MS1003SH and MS1004SH to meet the growing demand for power conservation.

These ICs incorporate a super standby mode to optimize power efficiency under micro loads.

The MS1003SH and MS1004SH consume less power in standby mode than conventional ICs. The ICs

incorporate various functions to make it more user-friendly and to make it easier to design a power supply

with fewer external components.

1.2 Characteristics

1)

Quasi-resonant design for high efficiency and low noise

2)

Four-step soft start function (40 ms/step)

3)

Onboard startup circuit requires no startup resistor, dramatically reducing losses in the startup circuit.

4)

The automatic trough skip function controls increases in oscillation frequency and improves efficiency

under light loads.

5)

Auto burst function improves efficiency under light loads with no additional components.

6)

Super standby mode improves efficiency under micro loads.

7)

Soft drive circuit reduces noise.

8)

Thermal shutdown, overvoltage protection, and overload protection (timer latch)

9)

Primary current limit circuit incorporates an input voltage dependence correction circuit to reduce the

number of components required.

10) Bias assist function for startup circuit

11) Vcc-GND short circuit protection function

12) SOP-8 package employed for compact dimensions

1.3 Applications

Televisions, video recorders, refrigerators, washing machines, air conditioners and other appliances in

which reduced standby power consumption is a design goal.

1.4 Appearance and dimensions

Unit: mm