SC414MLTRT Integrated Circuits (ICs)

Introduction

SC414MLTRT is a highly efficient step-down switching regulator from Seiko Instruments. It supplies power within a rated voltage output range of 0.6-5.5V, to meet the power supply needs of products such as portable devices. This regulator also provides high power conversion efficiency, requires no external compensation, and has a built-in soft-start function.

Application Field

• Cell phones.
• PDAs.
• Digital cameras.
• Portable audio players.
• Portable game consoles.

Working Principle

The SC414MLTRT uses a standard two-phase interleaved switching regulator. In this type of regulator, two power switches called an ‘upper’ and ‘lower’ switch are driven alternately to create two phase waveforms of VIN (input voltage) which are 180 degrees out of phase from each other. This waveform is then transformed into a waveform of output voltage VOUT.

The two switching phases result in a very low ripple waveform on the output current. It also reduces the input ripple noise components by mounting two sets of compensation components – namely, an inductor (L1) and capacitor (C1) – in series with each phase. This compensates for the phase difference between VIN and VOUT, resulting in an output with low noise and a wide operating temperature range.

The soft-start feature ensures that the output voltage rises gradually when the regulator is first powered up, reducing power supply “surges” or other disturbances that may be caused by an abrupt increase of output voltage.

Finally, the SC414MLTRT’s output DC voltage is adjusted by controlling the duty ratio of the two switches, using a control feedback loop.

Conclusion

The SC414MLTRT is a highly efficient and reliable step-down switching regulator which is capable of powering a wide range of portable devices. Its built-in soft-start feature, low noise output, and wide operating temperature range make it an ideal choice for these types of applications.