A Crystal-Less BLE Transmitter with -86dBm FrequencyHopping Back-Channel WRX and Over-the-Air Clock Recovery from a GFSK-Modulated BLE Packet packet, meaning the TX LO is ready before the end of the ADV event. 8MHz also relaxes the required BPF center frequency and quality factor. Using two LOs allows for receiving and transmitting on different BLE channels and for optimizing each PLL controller.

📋 论文概要

本文提出了一种无晶振的BLE发射器，通过从GFSK信号中恢复时钟，省去了外部晶振。同时集成了跳频反向通道唤醒接收机（WRX），实现了-86dBm的高灵敏度，并利用APU校准PLL以消除GFSK调制影响。

💡 主要创新点

• 首次实现无晶振BLE发射器，通过从GFSK调制信号中恢复参考时钟，降低系统成本和体积。
• 提出跳频反向通道WRX架构，在低功耗下实现-86dBm灵敏度，支持BLE唤醒功能。
• 设计了嵌入APU的Type-I ADPLL，在锁定状态下动态校准数字控制字，消除GFSK频率调制对PLL的影响。

🏷 关键词

📄 原文摘要

Benton H. Calhoun2, David D. Wentzloff1 Figure 30.7.3 shows a simplified block diagram for both PLLs for reference recovery from the BLE packet and TX transmission. It is a type-I ADPLL with an embedded averaging processing unit (APU) to calibrate the digital control word (DCW) while the PLL is locked. The APU is required because the 8MHz reference is a data-whitened, GFSK-modulated BLE packet, and the FM needs to be removed. The frequency accuracy increases with increasing averaging time, and with enough PLL cycles, the influence from GFSK modulation is minimized. The PLLs in the RX/TX paths are controlled by different frequency control words (FCW) and work at separate frequencies. This reduces mutual coupling between the 2 LOs and enables the TX to transmit in any channel. The LC oscillator (Fig. 30.7.3) uses both NMOS and PMOS cross-coupled pairs for negative resistance and a digitally tuned resistor tail, which helps keep the transistors out of triode

👥 作者与机构

Abdullah Alghaihab1, Xing Chen1, Yao Shi1, Daniel S. Truesdell2,