•
Shorting “MID” to “LOW” mutes the speaker audio.
•
Shorting “MID” to “HIGH” provides maximum gain.
•
Default (no connection) provides 10dB of gain.
The maximum output power is specified to provide up to two Watts into a 4-Ohm speaker load. Note that this
output power is drawn from the on-board 5V supply.
The speakers are driven using a Bridged-Tied Load (BTL) amplifier configuration. This is a differential speaker
connection. As such, each speaker should be wired directly to the appropriate pair of connections for that speaker.
•
Do not connect the speaker low sides (-) to ground
•
Do not short the speaker low connections together.
Auto-Calibration Reference Voltage (J17)
Connector J17 is a two-pin header used for auto-calibration.
1
GND
2
AutoCal Reference Value
The Diamond Systems Corporation AutoCal routines read the exact voltage calibration values from the AutoCal-
Flash. There are four analog values that need to be measured and stored in the AutoCal flash during manufacturing
test. Those values are produced from a very stable power source.
The values stored to AutoCal flash can be measured at header J17, where pin 1 is ground and pin 2 is one of the
positive values shown in the following table, depending on the selection of the Cal-Mux. The table gives the
approximate values of the four AutoCal values.
Cal-Mux
Value
0
5.5mV
1
1.2V
2
2.48V
3
4.96V
Note: Disconnect the measurement cables after measuring the voltages and before initiating the
actual auto-calibration.
LCD Panel, LVDS Interface (J24)
Connector J24 provides access to the internal LVDS LCD display drivers. Note that the LCD also requires the
backlight to be connected (J28, below) to function correctly.
Diamond Systems Corporation
Athena II User Manual
Page 29
Figure 14: J24 LCD Panel Connector
