A High Voltage CMOS Transceiver for Low-Field NMR with a Maximum Output Current of 1.4 App
A High Voltage CMOS Transceiver for Low-Field NMR with a Maximum Output Current of 1.4 App
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最大输出电流为 1.4 App 的低场 NMR 高压 CMOS 收发器
DOI：
10.1109/iscas45731.2020.9181025
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
J. Anders
中科院分区：
文献类型：
--
作者：
H. Bürkle;Kevin Schmid;T. Klotz;R. Krapf;J. Anders
本文介绍了一种用于低场核磁共振波谱的全集成收发芯片。该芯片将传统的低中频(Low-IF)接收器与高压(HV)H桥功率放大器(PA)和PLL频率合成器集成在一起。该接收机由低噪声放大器(LNA)、正交下变频混频器和基带放大器组成。它的实际输入参考电压噪声密度为1.1nV/√赫兹；集成的PLL频率合成器支持4 MHz至100 MHz的工作频率，覆盖台式和便携式核磁共振的所有相关Larmor频率。片内功率放大器可以将1.4App驱动到1Ω电阻中，并将1.6App驱动到3 mm的平行调谐核磁共振线圈中。当工作在1.45T非垫片核磁共振磁体内的3 mm核磁共振线圈时，该系统的自旋灵敏度为9.2×10~(15)Spins/√Hz，浓度灵敏度为1.79 mm/√Hz。
In this paper, we present a fully integrated transceiver ASIC for low field NMR spectroscopy. The chip integrates a conventional low intermediate frequency (low-IF) receiver together with a high-voltage (HV) H-bridge power amplifier (PA) and a PLL frequency synthesizer. The receiver consists of a low noise amplifier (LNA), a quadrature down-conversion mixer and a baseband amplifier. It achieves a measured input-referred voltage noise density of 1.1 nV/√Hz;. The integrated PLL frequency synthesizer supports operating frequencies between 4 MHz and 100 MHz, covering all relevant Larmor frequencies of benchtop and portable NMR. The on-chip PA can drive up to 1.4 App into a 1Ω resistor and 1.6 App into a 3mm, parallel-tuned NMR coil. When operating with a 3mm NMR coil inside a 1.45T unshimmed NMR magnet, the system achieves a spin sensitivity of 9.2 × 1015 spins/√Hz and a concentration sensitivity of 1.79 mM/√Hz.