73M1903 Data Sheet
DS_1903_032
Trans-Hybrid Loss (THL)
Trans-Hybrid Loss is by definition the loss of transmit signal from Tip/Ring to the receive inputs on the
modem IC. This definition is only valid when driving a specific phone line impedance. In reality, phone
line impedances are never perfect, so this definition isn’t of much help. Instead, as an alternate definition
that helps in analysis for this modem design, THL is the loss from the transmit pins to the receive pins. In
this definition the worst-case THL from the transmit pins to the Receive pins is 10.8 dB. An insertion loss
of 7 dB is assumed accounting for losses due to switch, bridge and transformer.
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Rev. 2.0
TERIDIAN [ TERIDIAN SEMICONDUCTOR CORPORATION ]
