HA17384SPS Datasheet, PDF (1/29 Pages) Hitachi Semiconductor – High Speed Current Mode PWM Control IC for Switching Power Supply

HA17384SPS/SRP, HA17384HPS/HRP,
HA17385HPS/HRP
High Speed Current Mode PWM Control IC
for Switching Power Supply
REJ03F0149-0300
(Previous: ADE-204-028B)
Rev.3.00
Jun 15, 2005
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.
Rev.3.00 Jun 15, 2005 page 1 of 28