HA17384SPS/SRP, HA17384HPS/HRP,

HA17385HPS/HRP

High Speed Current Mode PWM Control IC

for Switching Power Supply

ADE-204-028A (Z)

2nd Edition

Nov. 1999

Description

The HA17384S/H and HA17385H are PWM control switching regulator IC series suitable for highspeed,

current-mode switching power supplies. With ICs from this series and a few external parts, a small, low

cost flyback-transformer switching power supply can be constructed, which facilitates good line regulation

by current mode control. Synchronous operation driven after an external signal can also be easily obtained

which offers various applications such as a power supply for monitors small multi-output power supply.

The IC series are composed of circuits required for a switching regulator IC. That is a under-voltage

lockout (UVL), a high precision reference voltage regulator (5.0 V ± 2%), a triangular wave oscillator for

timing generation, a high-gain error amplifier, and as totem pole output driver circuit which directly drives

the gate of power MOSFETs found in main switching devices. In addition, a pulse-by-pulse type, high-

speed, current-detection comparator circuit with variable detection level is incorporated which is required

for current mode control.

The HA17384SPS includes the above basic function circuits. In addition to these basic functions, the H

Series incorporates thermal shut-down protection (TSD) and overvoltage protection (OVP) functions, for

configuration of switching power supplies that meet the demand for high safety levels.

Between the HA17384 and HA17385, only the UVL threshold voltages differ as shown in the product

lineup table.(See next page.)

This IC is pin compatible with the “3842 family” ICs made by other companies in the electronics industry.

However, due to the characteristics of linear ICs, it is not possible to achieve ICs that offer full

compatibility in every detail.

Therefore, when using one of these ICs to replace another manufacturer’s IC, it must be recognized that it

has different electrical characteristics, and it is necessary to confirm that there is no problem with the power

supply (mounting) set used.