Sierra Wireless airprime wismo218 User Manual
WA_DEV_W218_PTS_002
Rev 005
Page 79 of 109
Product Technical Specification &
Customer Design Guidelines
Application
If the « emergency » reset is used, it has to be driven by an open collector or an open drain output
(due to the internal pull-up resistor embedded into the WISMO218) as shown in the figure below.
(due to the internal pull-up resistor embedded into the WISMO218) as shown in the figure below.
GND
1
2
3
Push button
~RESET
Figure 39. Example of ~RESET Pin Connection with Push Button Configuration
GND
~RESET
Reset
command
T1
Rohm DTC144EE
Rohm DTC144EE
Figure 40. Example of ~RESET Pin Connection with Transistor Configuration
An open collector or open drain transistor can be used to drive the ~RESET pin. If an open collector is
chosen, the recommended digital transistor to use for T1 is the DTC144EE from ROHM.
chosen, the recommended digital transistor to use for T1 is the DTC144EE from ROHM.
Table 38. Reset Commands
Reset Command
~RESET
Operating Mode
1
0
Reset activated
0
1
Reset inactive
Note:
It is recommended to add a varistor (AVL5M02200) on the ~RESET pin in order to enhance the ESD
immunity.
immunity.