WA_DEV_W218_PTS_002 Rev 005 Page 50 of 109
Product Technical Specification &
Customer Design Guidelines
Impedance between
MICP and MICN
without 2.2K to
GND
Impedance between
MICP and MICN with
2.2K to GND
Maximum working voltage
( MICP-MICN)
(THD 10%)
Maximum rating voltage
(MICP or MICN)
* The input voltage depends on the input micro gain set by the AT command. Please refer to the document [2],
WISMO218 AT Commands Manual.
** Because both MICP and MICN are internally biased, it is necessary to use a coupling capacitor to connect an
audio signal provided by an active generator. Only a passive microphone can be directly connected to the MICP input.
Speaker Features
The speaker, SPK, can either have a single-ended or a differential connection. However, it is strongly
recommended to use a differential connection in order to reject common mode noise and TDMA
noise. Moreover, in single-ended mode, half (½) of the power is lost.
When using a single-ended connection, be sure to have a very good ground plane, very good filtering
as well as shielding in order to avoid any disturbance on the audio path.
Table 17. Speaker Details
Speakers Outputs Power
The maximal specifications given below are available with the maximum power output configuration
values set by an AT command. The typical values are recommended.
