TI中文支持网问下，EVM430FR6047的CH0_OUT连接了换能器，通过换能器0发送，然后换能器1接收，信号走CH0_IN进入。那为啥CH0_OUT还通过一个电容和CH0_IN连接那，这个是必须的吗？有什么作用那？
Susan Yang：
这个请您参考一下 www.ti.com/…/msp430fr6047.pdf
7.1.4 Transducer Connection to the USS Module
TI recommends 1% error tolerance for the external termination resistors (Rterm0 and Rterm1) and the AC coupling capacitors (Cac0 and Cac1). Typical value of the termination resistors is in the range of 150 to 400 Ω, the AC coupling capacitors are 1 to 2 nF. Actual values should be determined to meet the requirements of each application.
