• Microelectronics
  • Vol. 52, Issue 3, 407 (2022)
TANG Xiaoke1, HU Yi1, HOU Jiali1, DENG Heng2, MENG Hao2, WANG Huaiyu3, and LI Jing2
Author Affiliations
  • 1[in Chinese]
  • 2[in Chinese]
  • 3[in Chinese]
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    DOI: 10.13911/j.cnki.1004-3365.210360 Cite this Article
    TANG Xiaoke, HU Yi, HOU Jiali, DENG Heng, MENG Hao, WANG Huaiyu, LI Jing. A CMFB Loop Stability Enhancement Circuit Based on Feedforward Path gmf[J]. Microelectronics, 2022, 52(3): 407 Copy Citation Text show less

    Abstract

    Based on a 0.13 μm CMOS process, a new common-mode feedback circuit for three-stage fully differential operational amplifier was proposed and designed. A typical two-stage fully differential and source-follower structure with a Miller compensation structure was used as the amplification stage of the three-stage operational amplifier. By introducing a feedforward path in the common-mode feedback circuit to generate two zeros, the stability of the operational amplifier had been improved, which could solve the problem that multiple poles are difficult to compensate in the traditional common mode feedback loop. The simulation results showed that the gain was 70.4 dB, the unity gain bandwidth (GBW) was 56 MHz, and the phase margin was 85.5° under 1.2 V voltage. Compared with the traditional circuit without a feedforward path, the GBW and phase margin of the new common-mode feedback circuit were increased by 8.2 MHz and 17.4° respectively. An operational amplifier with this common-mode feedback structure could achieve lower power supply voltage and better phase margin.
    TANG Xiaoke, HU Yi, HOU Jiali, DENG Heng, MENG Hao, WANG Huaiyu, LI Jing. A CMFB Loop Stability Enhancement Circuit Based on Feedforward Path gmf[J]. Microelectronics, 2022, 52(3): 407
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