Specifications

Migration from MC35 to MC35i
RELEASED
MC35_MC35i_MIG_V01.03 Page 18 of 33 23.04.03
3.6 Control signals
Input and Output control signals are identical with both MC35 and MC35i device, except for
POWER and ACCU_TEMP.
3.7 Interfaces
MC35 and MC35i interfaces are compatible. Detailed comparison values for each
interface can be found in the following chapters. For further information please consult [3].
3.7.1 Serial interface
Each device uses the same serial interface with identical pin positions as described in [1], [3].
3.7.2 SIM card interface
There are no changes on the integrated SIM interface with MC35 and MC35i.
3.7.3 Antenna interface
There are no changes on the RF antenna interface with MC35 and MC35i.
Due to different hardware platforms minor changes might be necessary to improve for
example current consumption or harmonics.
3.7.4 Audio interface
Both MC35 and MC35i comprise two analogue audio interfaces, each with an analogue
microphone input and an analogue loudspeaker output.
To suit several types of equipment, there are several audio modes available which can be
selected with the AT^SNFS command. The electrical characteristics of the voiceband part
vary with the audio mode. For example, sending and receiving amplification, sidetone paths,
noise suppression etc. depend on the selected mode and can be set with AT commands
(except for mode 1).
All analogue microphone inputs and loudspeaker outputs are balanced. A power supply for
electret microphones is implemented in both interfaces, too. If not needed, they have to be
decoupled with capacitors.
MC35i only: Independently of the audio mode, analogue interfaces 1 or 2 can be
selected and configured by AT commands.
Detailed instructions on using AT commands are presented in the AT Command Set.
The specification of the audio interface signals and the voice band characteristics are
identical for MC35 and MC35i. For details refer to the Hardware Interface Description.
3.8 Electrical discharge
MC35 and MC35i are identically protected against electrical discharge.