User's Manual

MC55/56 Hardware Interface Description
Confidential / Preliminary
s
MC55/56_hd_v03.00 Page 78 of 104 16.08.2005
Function Signal name IO Signal form and level Comments
EPP2 O
EPN2 O
V
O
max = 3.7Vpp
See also Table 30.
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 30.
Balanced audio output.
Can be used to directly
operate an earpiece.
If unused keep pins open.
MICP1 I
MICN1 I
R
I
 50kΩ differential
V
I
max = 1.03Vpp
See also Table 31.
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
= 2kΩ differential
V
I
max = 1.03Vpp
See also Table 31.
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.
Explanation of signal names: P = positive, N = negative