AC75 Hardware Interface Description
Strictly confidential / Preliminary
s
AC75_HD_V00.202
Page 75 of 120
27.04.2006
3.17 Control
Signals
3.17.1 Synchronization
Signal
The synchronization signal serves to indicate growing power consumption during the transmit
burst. The signal is generated by the SYNC pin. Please note that this pin can adopt three
different operating modes which you can select by using the AT^SSYNC command: the
mode AT^SSYNC=0 described below, and the two LED modes AT^SSYNC=1 or
AT^SSYNC=2 described in [1] and Section 3.17.2.
The first function (factory default AT^SSYNC=0) is recommended if you want your
application to use the synchronization signal for better power supply control. Your platform
design must be such that the incoming signal accommodates sufficient power supply to the
AC75 module if required. This can be achieved by lowering the current drawn from other
components installed in your application.
The timing of the synchronization signal is shown below. High level of the SYNC pin
indicates increased power consumption during transmission.
Figure 34: SYNC signal during transmit burst
*)
The duration of the SYNC signal is always equal, no matter whether the traffic or the
access burst are active.
Transmit burst
1 Tx 577 µs every 4.616 ms
2 Tx 1154 µs every 4.616 ms
SYNC signal
*)
t = 180 s
μ