Telit Wireless Solutions GM862-GPS - Manual (Page 5)

GM862-GPS Hardware User Guide
1vv0300728 Rev. 0 - 27/04/06
Reproduction forbidden without Telit Communications S.p.A. written authorization - All Right reserved page 5 of 55
2 Hardware Commands
2.1 Turning ON the GM862-GPS
To turn on the GM862-GPS the pin ON# must be tied low for at least 1 second and then released.
The maximum current that can be drained from the ON# pin is 0,1 mA.
A simple circuit to do it is:
NOTE: don't use any pull up resistor on the ON# line, it is internally pulled up. Using pull up resistor may bring to
latch up problems on the GM862-GPS power regulator and improper power on/off of the module. The line ON# must
be connected only in open collector configuration.
NOTE: In this document all the lines that are inverted, hence have active low signals are labeled with a name that
ends with a "#" or with a bar over the name.
TIP: To check if power has raised it is possible to monitor the START line, when this line goes high the module is
powered on, but before it remains on the device needs other 900 ms for software startup. Hence check the PWRCTL
line and 900 ms after its transition to high it is possible to release the ON# pin.
ON#
Power ON impulse
GND
R1
R2
Q1