Speaker - Advantech SOM-ETX Series Design Manual

5.14.2 Speaker

The SPKR output from the SOM-ETX module is a CMOS level signal. It can control
an external FET or logic gate that drives an external PC speaker. The SOM-ETX
modules SPKR output should not be directly connected to either a pull-up or a pull-
down resistor. The SPKR signal is often used as a configuration strap for the core
chipset in SOM-ETX modules. A pull-up or pull-down on this signal can override the
internal setting in the module and result in malfunction of the module.
Advantech SOM-ETX Design Guide
SM-ETX
SPKER
10K
Figure 5-42 Speaker Connections
Chapter 5 Carrier Board Design Guidelines
Carryboard
VCC
2
33
1N4148
1
BUZZER
3
1
MMBT3904
C142
0.1u 0.01u
2
109