HA17384 Datasheet | Hitachi Semiconductor

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 posed 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, highspeed, current-detection parator 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 patible with the “3842 family” ICs made by other panies in the electronics industry. However, due to the characteristics of linear ICs, it is not possible to achieve ICs that offer full patibility 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. HA17384SPS/SRP,...