Download Siemens XT75 Specifications

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XT65/XT75 Hardware Interface Overview
6.5 Pin Assignment and Signal Description
Table 17: Signal description
Function
Signal name
IO
Signal form and level
Comment
Synchronization
SYNC
O
VOLmax = 0.3V at I = 0.1mA
There are two alternative options
for using the SYNC pin:
VOHmin = 2.3V at I = -0.1mA
VOHmax = 3.05V
n Tx = n x 577µs impulse each
4.616ms, with 180µs forward time.
a) Indicating increased current
consumption during uplink transmission burst. Note that the timing
of the signal is different during
handover.
b) Driving a status LED to indicate
different operating modes of
XT65/XT75. The LED must be
installed in the host application.
To select a) or b) use the
AT^SSYNC command.
If unused keep pin open.
RTC
backup
VDDLP
I/O
RI ≈ 1kΩ
VOmax = 4.5V
If unused keep pin open.
VBATT+ = 4.2V:
VO = 3.3V at IO = -500µA
VBATT+ = 0V:
VI = 2.4V…4.5V at Imax = 25µA
ASC0
RXD0
O
Serial
interface
TXD0
I
CTS0
O
RTS0
I
DTR0
I
DCD0
O
DSR0
O
RING0
O
XT65_XT75_HO_v00.130
Confidential / Preliminary
VOLmax = 0.2V at I = 2mA
VOHmin = 2.55V at I = -0.5mA
VOHmax = 3.05V
Serial interface for AT commands
or data stream.
If lines are unused keep pins open.
VILmax = 0.8V
VIHmin = 2.15V
VIHmax = VEXTmin + 0.3V = 3.05V
Page 36 of 67
2006-10-12