Specifications

SB-P-06-4066
sepura
Mobile & Gateway Accessory i/f
specification
30th July 2012
Page 27 of 39
Issue 7c
© Sepura plc 2011
‗PTT Jack Socket:
Pin
Signal Name
1
GND
2
Jack key input
10 kΩ pull-up to 5 V in the AIU.
Connecting this pin to GND via a 22 kΩ (or less) resistance will
cause the console software to see ‗Accessory Key 5‘ pressed on
AAI2.
3
nPTT (AAI-2 Channel)
Note if an SRH side jack microphone is connected in the via the microphone jack socket, the
ACC_ID signal will be shorted to GND (pins 1 and 2 shorted) by the mono jack plug, so the
remote microphone accessory will be detected correctly
AIU MK 2 JACK CONNECTORS
On the Mk 2 version of the Accessory Interface Unit (AIU) some of the pin functionality is re-
allocated on the AAI2 connector and the connector is renamed ―Remote Control Interface‖
(RCI) (see section 7).
The AIU Mk 2 has a VOGAD circuit in line with both of the microphone paths. The gain on the
AAI1 and AAI2 mic paths can be locally varied according to the type of microphone connected
and a microphone detect function is provided on AAI1.
AAI2 – VIA JACK CONNECTOR
For AIU Mk 2 the AAI2 audio input functionality is only available via the jack connector. The
performance and expected signal properties are slightly different from those of AIU Mk 1.
Jack Pin
Number
Signal
Name
Input/
Output
Description
Performance
3
MIC_SIG
I
Microphone input
Normal gain: 150mV
rms
nominal
High gain: 15mV
rms
nominal
Low gain: 1.2 V
rms
nominal.
2.2 kΩ internal pull up to 8V.
The higher bias voltage and the addition of microphone load detection, allow this interface to
operate with active remote microphones e.g.