Datasheet

Configuration Switches
2-6 SHARC Audio EZ-Extender Manual
Audio Loopback Switches (SW1–6)
The audio loopback switches (SW1—6) are intended for test purposes only.
The switches loop-back any analog output signal generated from an
AD1939 codec’s digital-to-analog converter (DAC) circuit to ana-
log-to-digital converter (ADC) circuit:
• SW1—2 are designed for the master codec (AD1939A)
• SW3—4 are designed for the secondary codec (AD1939B)
• SW5—6 are designed for the third codec (AD1939C)
By default, switches SW1–6 are all OFF.
Audio In1 Left Selection Switch (SW7)
The audio selection switch (SW7) connects the left channel of the In1 line,
connected to the AD1939’s ADC1 circuit, to either the single-ended RCA
connectors or the differential DB25 connector. By default, the switch is
set up to use the RCA connectors. The switch circuit is connected to
AD1939A (codec A). To use the standard, off the shelf DB25 connector
to XLR cables, change the switch to the differential setting; see Table 2-1.
See also “Differential In/Out Connectors (P1–5)” on page 2-18.
Table 2-1. Audio In1 Left Selection Switch (SW7)
SW7 Position Single-Ended Mode
RCA IN (Default)
Differential Mode
DB25 IN (P1)
SW7.1 ON OFF
SW7.2 OFF ON
SW7.3 ON OFF
SW7.4 OFF ON