DTMF/FSK Modem for Medical

참조 설계 작성자: Analog Devices

DTMF/FSK Modem for Medical
Configuration for Bell 202 2-Wire Dial-Up Half Duplex Operation. The switches U2A and U2C connect R2 and C1 across the transformer while receiving, while R1 is used for impedance matching while transmitting with U2B and U2D turned on