Sierra Wireless AIRPRIME WISMO218 - Manual (Page 63)

WA_DEV_W218_PTS_002 Rev 006 April 29, 2010 63
Product Technical Specification &
Customer Design Guidelines Interfaces
3.13. ON/~OFF Signal
The ON/~OFF pin is used to switch ON or switch OFF the AirPrime WISMO218.
ON/~OFF signal is internally connected to the permanent 3.0V supply regulator inside the AirPrime
WISMO218 via a pull-up resistor. Once there is VBATT supply to the AirPrime WISMO218, this 3.0V
supply regulator will be enabled and so the ON/~OFF signal is by default at HIGH level.
A LOW level signal has to be provided on the ON/~OFF pin to switch ON the AirPrime WISMO218.
Caution: All external signals must be inactive when the AirPrime WISMO218 is OFF to avoid any damage
when starting and to allow the AirPrime WISMO218 to start and stop correctly.
Avoid using application MCU GPIO to directly control the ON/~OFF signal of the AirPrime
WISMO218; instead, control this signal via an open collector switching transistor.
3.13.1. Features
Table 25: Electrical Characteristics of the ON/~OFF Signal
Parameter I/O Type Minimum Typ. Maximum Unit
V
IH
2V8 2.4 - 3.0 V
V
IL
2V8 - - 0.4 V
3.13.2. Pin Description
Table 26: ON/~OFF Signal Pin Descriptions
Signal Pin Number I/O I/O Type Description
ON/~OFF 37 I 2V8 AirPrime WISMO218 Power ON/OFF