%A Wentao Wu(伍文涛), Zhirong Lin(林志荣), Zhi Ni(倪志), Peizhan Li(李佩展), Tiantian Liang(梁恬恬), Guofeng Zhang(张国峰), Yongliang Wang(王永良), Liliang Ying(应利良), Wei Peng(彭炜), Wen Zhang(张文), Shengcai Shi(史生才), Lixing You(尤立星), and Zhen Wang(王镇) %T Development of series SQUID array with on-chip filter for TES detector %0 Journal Article %D 2022 %J Chin. Phys. B %R 10.1088/1674-1056/ac2b91 %P 28504-028504 %V 31 %N 2 %U {https://cpb.iphy.ac.cn/CN/abstract/article_124379.shtml} %8 2022-01-13 %X A cold preamplifier based on superconducting quantum interference devices (SQUIDs) is currently the preferred readout technology for the low-noise transition edge sensor (TES). In this work, we have designed and fabricated a series SQUID array (SSA) amplifier for the TES detector readout circuit. In this SSA amplifier, each SQUID cell is composed of a first-order gradiometer formed using two equally large square washers, and an on-chip low pass filter (LPF) as a radio-frequency (RF) choke has been developed to reduce the Josephson oscillation interference between individual SQUID cells. In addition, a highly symmetric layout has been designed carefully to provide a fully consistent embedded electromagnetic environment and achieve coherent flux operation. The measured results show smooth V-Φ characteristics and a swing voltage that increases linearly with increasing SQUID cell number N. A white flux noise level as low as 0.28 μΦ0/Hz1/2 is achieved at 0.1 K, corresponding to a low current noise level of 7 pA/Hz1/2. We analyze the measured noise contribution at mK-scale temperatures and find that the dominant noise derives from a combination of the SSA intrinsic noise and the equivalent current noise of the room temperature electronics.