UC864-E Hardware User Guide
1vv0300766a Rev.1 - 31/01/08
10.4 Electrical Characteristics
10.4.1 Input lines (microphone)
The two transmit blocks are fully equivalent, connected in Differential mode
Line coupling | AC (*) |
Line type | Balanced |
Coupling capacitor | ≥ 100nF |
Differential input resistance | 20kΩ |
Differential input voltage | ≤ 1,03Vpp @ HSMicG=0dB |
Table 1. “Mic_MT” 1st differential microphone path
Line coupling | AC (*) |
Line type | Balanced |
Coupling capacitor | ≥ 100nF |
Differential input resistance | 20kΩ |
Differential input voltage | ≤ 1,03Vpp @ HFMicG=0dB |
Table 2. “Mic_HF” 2nd differential microphone path
Due to the fact that particular OEM applications need a single line connection, a Single Ended configuration could be implemented, but halving the useful microphone signal.
In both cases the OEM circuitries shall be carefully designed to reduce the common mode noise typically generated on the ground plane.
WARNING
In the previous tables, the line coupling definition AC (*) means that:
the signals from microphone must be connected to the input lines of the
Not respecting this constraint, the input stage will be damaged!
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Rights Reserved | page 39 of 51 |
