CMX7861 FirmCODEC® Programmable Baseband Interface
CMX7861
5.3 Signal Output
5.3.1 Output Signal Routing
The CMX7861 has four possible analogue outputs:
Differential output 1 - OUTPUT1P and OUTPUT1N (or I output for an I/Q-based system)
Differential output 2 - OUTPUT2P and OUTPUT2N (or Q output for an I/Q-based system)
Single-ended output 3 – OUTPUT3 that can drive headset/earpieces
Differential output 4 – OUTPUT4P and OUTPUT4N – a low-impedance speaker driver
The CMX7861’s two DACs (DAC 1 and DAC 2) can output analogue waveforms on any or all of these
four outputs. CMX7861 allows us to connect the two DACs to any of the four analogue outputs.
Due to the highly-flexible nature of the CMX7861 and the multitude of input and output configurations, it is
important to clearly understand the differences between Pin/Signal names, and the internal signal streams
controlled by most of the registers. To help clarify this situation, the following convention has been used
throughout the text and on diagrams within this document:
Outputs from the device to external systems will be referred to as OUTPUT1, 2, 3, or 4. Where
appropriate, OUTPUT 1 and 2 may also be referred to as I and Q outputs respectively (if the
description is specifically for an I/Q-based system).
Internal signal streams routed to the four outputs and processed by the two DACs will be referred to
as DAC1 and/or DAC2 samples.
Figure 5 Analogue Output Routing, shows the analogue output signal routing and control.
2012 CML Microsystems Plc
Page 12
D/7861_FI-1.x/2
CMLMICRO [ CML MICROCIRCUITS ]
