User Guide

PAMS
Technical Documentation
NME–3
Technical Information
Page 8
Issue 1 10/99
Table 2. External Signals (continued)
Unit / NotesMaximumTypical /
Nominal
MinimumLine SymbolPin / Conn.
7/Data RTS +/– 3.3 +/– 15 V / inactive
V/ active
8/Data CTS +/– 3.3 +/– 15 V / inactive
V/ active
9/Data RI +/– 3.3 +/– 15 V / inactive
V/ active
Protection Circuits
Power is first filtered and protected agains Voltages>30V and Reverse
Voltage. The Supply Monitor switches off the 12V Supply via Si–Switch at
supply Voltages > 16.25V. Aux–Protect clamps peak pulses that are not
covered by the Supply Monitor. Three signals are provided to detect
different supply–voltage levels by other hard– and software:
_OVERVOLTAGE is active at >16.25V, _POWERFAIL at <10,9V.
_POWERCRITICAL is active at a drop of more than 5% on 3.8V Supply. A
LowPower Regulator is used for sleep power for CCONT and MAD.
Three different Voltages are used in CD949. 3.8V for CCONT
(VBCCONT), 8V for RF–PREAMP, AUDIO and for VBCCONT
Regulator,HS and 12V for RFPA, Audio PowerAmp. 12V and 8V can be
switched by PowerOn and automatically by _OVERVOLTAGE.