Siemens MC45, Manual

Page: 64 / 90

MC45 Hardware Interface Description
P R E L I M I N A R Y
MC45_HD_01_V00.02a Page 64 of 90 12.08.2002
Function Signal name IO Signal form and level Comments
/RXD0 O
/TXD0 I
/CTS0 O
/RTS0 I
/DTR0 I
/DCD0 O
/DSR0 O
RS-232 (0)
interface
/RING0 O
V
OL
max = 0.2V at I = 1mA
V
OH
min = 2.35V at I = -1mA
V
OH
max = 2.73V
V
IL
max = 0.5V
V
IH
min = 1.95V, V
IH
max=3.3V
/DTR0, RTS0: Imax = -90µA at V
IN
= 0V
/TXD0: Imax = -260µA at V
IN
= 0V
First serial interface for AT
commands or data stream.
Please note that the /TXD0
pin draws, for 350ms, an
additional current of max.
60µA when MC45 is
activated. See timing
characteristics in Figure 6
If unused keep pins open.
/RXD1 O
/TXD1 I
/CTS1 O
RS-232 (1)
interface
/RTS1 I
V
OL
max = 0.2V at I = 1mA
V
OH
min = 2.35V at I = -1mA
V
OH
max = 2.73V
V
IL
max = 0.5V
V
IH
min = 1.95V, V
IH
max=3.3V
I
I
max = -90µA at V
IN
= 0V
Second serial interface for
AT commands.
Please note that the /TXD1
pin draws, for 350ms, an
additional current of max.
60µA when MC45 is
activated. See timing
characteristics in Figure 6
If unused keep pins open.
RFSDAI I
RXDDAI I
SCLK I
TFSDAI O Digital audio
interface
TXDDAI O
V
OL
max = 0.2V at I = 1mA
V
OH
min = 2.35V at I = -1mA
V
OH
max = 2.73V
V
IL
max = 0.5V
V
IH
min = 1.95V, V
IH
max=3.3V
I
I
max = 330µA at V
IN
= 3.3V
If unused keep pins open.
EPP2 O
EPN2 O
V
O
max = 3.7Vpp
See also Table 32.
The audio output is
balanced and can directly
operate an earpiece.
If unused keep pins open.
EPP1 O
EPN1 O
V
O
max = 3.7Vpp
See also Table 32.
Balanced audio output.
Can be used to directly
operate an earpiece.
If unused keep pins open.
MICP1 I
MICN1 I
R
I
≈ 50k
W
differential
V
I
max = 1.03Vpp
See also Table 33.
Balanced microphone
input. To be decoupled
with 2 capacitors (C
K
=
100nF), if connected to a
microphone or another
device.
If unused keep pins open.
MICP2 I
MICN2 I
R
I
= 2k
W
differential
V
I
max = 1.03Vpp
See also Table 33.
Balanced microphone
input. Can be used to
directly feed an active
microphone.
If used for another signal
source, e.g. op amp, to be
decoupled with capacitors.
If unused keep pins open.
Analog audio
interfaces
AGND Separate ground
connection for external
audio circuits.
Ex
planation of s
ignal names
:
P =
pos
itiv
e, N =
negativ
e