LEA-5, NEO-5, TIM-5H - Hardware Integration Manual
GPS.G5-MS5-09027-A2
Released
Design-in
Page 42 of 68
2.6.5
Active antenna supervisor (LEA-5H/5S/5A/5T, TIM-5H)
u-blox 5 Technology provides the means to implement an active antenna supervisor with a minimal number of
parts. The antenna supervisor is highly configurable to suit various different applications.
u-blox 5 Module
GND
RF_IN
GND
Active Antenna
V_ANT
VCC_RF
LNA
AADET_N
Antenna
Supervisor
Circuitry
external
antenna
voltage
supply
Figure 34: External antenna power supply with full antenna supervisor (for exact pin orientation see data sheet)
2.6.5.1
Short and open circuit active antenna supervisor
The Antenna Supervisor can be configured by a serial port message (using only UBX binary message). When
enabled the active antenna supervisor produces serial port messages (status reporting in NMEA and/or UBX
binary protocol) which indicates all changes of the antenna circuitry (
disabled
antenna supervisor, antenna
circuitry
ok
,
short
circuit,
open
circuit) and shuts the antenna supply down if required.
The active antenna supervisor provides the means to check the active antenna for open and short circuits and to
shut the antenna supply off, if a short circuit is detected. The state diagram in Figure 35 applies. If an antenna is
connected, the initial state after power-up is “Active Antenna OK”.
No
Super-
vision
Active
Antenna
OK
Open
Circuit
detected
Short
Circuit
detected
Powerup
Events AADET0_N
User controlled events
Disable Supervision
Enable Supervision
Short Circuit
detected
Disable
Supervision
Antenna
connected
Short Circuit
detected
open circuit
detected, given
OCD enabled
Periodic
reconnection
attempts
Figure 35: State diagram of active antenna supervisor
