AIO Product Manual
15
AIO-S Module (Cont.)
SPKR
– Voltage/Current Monitoring Inputs
The third and fourth inputs on the AIO-S module measure the voltage and current
supplied to a speaker (or haptic device) connected to the (+) and (-) outputs of the
SPKR connector to calculate impedance, resonance, or other value.
Voltage is monitored using separate wires connected to the (V+) and (V-) terminals of
the connector. This measures the voltage at the speaker without the influence of the
wires delivering the test signal. There is a precision current sense resistor within the
AIO-S module that is in series with the output. The voltage across this resistor is
measured using the fourth input of the module, yielding a current measurement.
Full-Scale Voltage, Current, and Dynamic Range:
Gain
Setting
Full-Scale
SPKR Voltage
Full-Scale
SPKR Current
Dynamic Range
(A-weighted)
x1
± 8.75V
± 4.375A
> 110dB
x10
± 875mV
± 437.5mA
> 105dB
x100
± 87.5mV
± 43.75mA
> 95dB
THDN (A-weighted):
<-95dB 20Hz
– 20kHz
Frequency Response:
± 0.5dB 20Hz
– 20kHz
Calibrated Accuracy:
0.25%
Class-D Amplified Outputs
Two amplified outputs are provided for connecting speakers or other devices. The first
output is part of the SPKR connector while the second uses the AMP1 connector. The
outputs are differential with (+) and (-) connections and the speaker should be
connected directly across them. Both the (+) and (-) outputs are biased at ~7.5V.
Note:
Connecting a speaker or other low impedance path from one of the outputs to
ground will cause the amplifier to shut down. If this happens, the AIO needs to be
power cycled for the amplifier to resume normal operation.
Output Power (THDN <.1%):
10W continuous at 1kHz
Maximum Output Voltage:
± 13.5V
Frequency Response:
± 0.5dB 20Hz
– 20kHz
