MAX-7 / NEO-7 / LEA-7 - Hardware Integration Manual
GPS.G7-HW-11006-1
Design
Page 31 of 55
3.4.3.3
Antenna supervision open circuit detection (OCD) (LEA-7N, MAX-7W)
The open circuit detection circuit uses the current flow to detect an open circuit in the antenna. Calculate the
threshold current using Equation 1.
Figure 27: Schematic of open circuit detection (for exact pin orientation see data sheet)
RF
Vcc
Rbias
R
R
R
I
_
3
2
2
•
+
=
Equation 1: Calculation of threshold current for open circuit detection
Antenna open circuit detection (OCD) is not activated by default on the MAX-7 module. OCD can be
mapped to PIO13 (EXTINT). To activate the antenna supervisor use the UBX-CFG-ANT message. For
more information about how to implement and configure OCD, see the
u-blox 7 Receiver Description
including Protocol Specification
If the antenna supply voltage is not derived from VCC_RF, do not exceed the maximum voltage rating of
AADET_N.
For recomended parts, see section 3.5.
