This paper presents a proposed ultra-low-power second order feedforward (FF) delta sigma (ΔΣ) modulator using two different integrators structures for implantable biomedical devices in the MICS band. In fact, the first active integrator is designed using a proposed optimized bulk driven telescopic operational transconductance amplifier while the second passive one is designed using a MOS Parametric amplifier. The ΔΣ modulator is designed for a signal bandwidth of 150 kHz with an oversampling ratio of 50. In fact, the proposed circuit is simulated using system-level model as well as device-level description for TSMC 0.18 μm CMOS technology. In this circuit, an input signal of −1.93 dBFS magnitude and 68.66 kHz frequency was sampled at a frequency of 15 MHz. Device-level simulations results indicate that the designed ΔΣ FF modulator achieves a signal to noise ratio (SNR) of 63 dB and a resolution of 10.18bits. It consumes only 3 µW under a ± 0.5 V supply voltage.

本文提出了一种超低功耗二阶前馈 (FF) delta sigma (ΔΣ) 调制器，该调制器使用两种不同的积分器结构，用于 MICS 频段的可植入生物医学设备。事实上，第一个有源积分器是使用建议的优化体驱动伸缩运算跨导放大器设计的，而第二个无源积分器是使用 MOS 参数放大器设计的。ΔΣ 调制器设计用于 150 kHz 的信号带宽，过采样率为 50。实际上，所提出的电路是使用系统级模型以及 TSMC 0.18 μm CMOS 技术的器件级描述进行仿真的。在该电路中，以 15 MHz 的频率对 -1.93 dBFS 幅度和 68.66 kHz 频率的输入信号进行采样。器件级仿真结果表明，所设计的 ΔΣ FF 调制器实现了 63 dB 的信噪比 (SNR) 和 10.18 位的分辨率。它在 ± 0.5 V 电源电压下仅消耗 3 µW。