DOI QR코드

DOI QR Code

Analysis of Emission Characteristics of DC/DC Converter with different Parts Layout

부품배치가 다르게 제작된 DC/DC컨버터의 Emission 특성분석

  • Received : 2018.10.29
  • Accepted : 2019.01.04
  • Published : 2019.01.31

Abstract

The system stability must be ensured from the switching noise due to the power conversion efficiency and power conversion system miniaturization. Therefore, countermeasures to reduce switching noise during power conversion are essential. Thus, in the previous paper, we constructed the DC / DC Buck Converter circuit using MPQ4432 driver of MPS, and simulated the switching noise characteristics which occurs when the components are arranged differently in the 4 - layer PCB circuit structure with reference plane. In this paper, two different simulated circuits are fabricated and the characteristics of the conducted emission and the radiated emission are analyzed in the same way as the simulation. As a result, it was confirmed that the Conducted Emission characteristic was reduced by 2 ~ 9dB in the low frequency band and 6 ~ 7dB in the high frequency band depending on the configuration of the current return path. And the radiated emission characteristic is reduced by 9 dB. Conducted emission simulation results show that 6 ~ 7dB in the low frequency range and 2 ~ 9dB in the measurement result are somewhat different. In the high frequency band, it is confirmed that the experimental and simulation results are about 7dB. And Radiated Emission confirmed 12dB decrease in simulation, but confirmed decrease of 9dB in measurement result. It is confirmed that there is a slight difference in the amount of reduction, but the design of the power conversion circuit improves the noise characteristics according to the configuration of the current return path.

전력 변환에는 전력 효율과 함께 전력 변환시스템의 소형화를 위해 적용하는 스위칭에 의한 잡음으로부터 시스템 안정성이 보장되어야 한다. 따라서 전력 변환시 스위칭 잡음을 감소시킬 수 있는 대책이 필수적이다. 따라서 이전 논문에는 MPS사의 MPQ4432 드라이버를 이용하여 DC/DC Buck Converter회로를 구성한 후 이를 reference plane을 갖는 4층 PCB 회로 구조에서 부품의 배치가 서로 다른 경우 발생하는 스위칭 잡음특성을 시뮬레이션 하였다. 본 논문에서는 시뮬레이션을 진행한 서로 다른 두 회로를 제작하여, 시뮬레이션과 동일하게 Conducted Emission특성과 Radiated Emission 특성을 분석하였다. 또한 측정결과와 시뮬레이션 결과와 비교하였다. 그 결과 Current Return Path의 구성에 따라 Conducted Emission특성이 저주파대역에서는 2~9dB, 고주파대역에서는 6~7dB 감소됨을 확인하였다. 그리고 Radiated Emission특성은 9dB 감소됨을 확인하였다. Conducted Emission 시뮬레이션 결과 저주파대역에서 6~7dB이고, 측정 결과는 2~9dB로 다소차이가 있음을 확인하였고, 고주파대역에서는 실험과 시뮬레이션에서 모두 7dB정도임을 확인하였다. 그리고 Radiated Emission은 시뮬레이션에서 12dB 감소를 확인하였지만, 측정결과 9dB의 감소를 확인하였다. 이로써 다소 감소량에는 차이가 확인되었지만 전력변환회로를 설계할 경우 Current return path의 구성에 따라 잡음 특성을 향상시킬 수 있음을 확인하였다.

Keywords

SHGSCZ_2019_v20n1_179_f0001.png 이미지

Fig. 1. Circuit of Buck Converter

SHGSCZ_2019_v20n1_179_f0002.png 이미지

Fig. 2. Parts Placement (a) Top layer of switching parts(case-A) (b) Top layer of switching parts(case-B)

SHGSCZ_2019_v20n1_179_f0003.png 이미지

Fig. 3. I/O Measurement (a) case-A (b) case-B

SHGSCZ_2019_v20n1_179_f0004.png 이미지

Fig. 4. CE characteristics in Broadband (a) CE Results in Simulation, (b)CE Results of Case-A, (c)CE Results of Case-B

SHGSCZ_2019_v20n1_179_f0005.png 이미지

Fig. 5. CE characteristic in Mobile-band (a) CE Results of Case-A, (b) CE Results of Case-B

SHGSCZ_2019_v20n1_179_f0006.png 이미지

Fig 6. Radiated Emission Measurement setup

SHGSCZ_2019_v20n1_179_f0007.png 이미지

Fig. 7. RE measurement result (a) Simulation result, (b) Results of case-A, (c) Results of case-B

SHGSCZ_2019_v20n1_179_f0008.png 이미지

Fig. 8. EMI-bicon Antenna measurement (a) Results of case-A, (b) Results of case-B

Table 1. Input-Output Measurement

SHGSCZ_2019_v20n1_179_t0001.png 이미지

Table 2. Results of CE characteristic for plus and return voltage

SHGSCZ_2019_v20n1_179_t0002.png 이미지

Table 3. Results of CE characteristic for plus and return voltage

SHGSCZ_2019_v20n1_179_t0003.png 이미지

Table 4. Simulations and experimental results decrease value

SHGSCZ_2019_v20n1_179_t0004.png 이미지

References

  1. Soo-sul Hwang, Jae-Deuk Lee, "Investigation and Circuit Analysis for DC-DC Converter", Korea aerospace Research institute, Vol. 5, No. .2 pp. 166-173, Nov. 2006.
  2. Young-jin Choi, Sang-june Kim, Tae-Kyung Kim, "DC/DC Switching Converter Characteristics", The institute of Electronics Engineers of Korea, pp. 743-746, Nov. 1999.
  3. Jin-Hong Park, "Analysis of Emission characteristics of DC/DC Converter by Component Placement",Korea Academia-Industrial Cooperation Society, Vol. 19, No. 2, pp. 639-653, 2018.
  4. Lho, Young Hwan, Lee, Sang Yong, Kim Yoon Ho, "A study on design of PWM DC/DC Power Converter", Korean Society for Railwav, pp. 209 -214, Nov. 2009.
  5. P.C.Adell, et al,"Total-Dose and Single-Event Effect in DC/DC Converter Control Circuitry", IEEE Transactions on Nuclear Science, Vol. 50, No. 6, Dec. 2003. DOI: http://dx.doi.org/10.1109/TNS.2003.820757
  6. "MPQ4432 Low Quiescent Current Synchronous Step-Down Converter", Monolithic Power System, Datasheet.