Active Antenna Supervisor (Lea-5H/5S/5A/5T, Tim-5H) - u-blox LEA-5 Series Hardware Manual

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.
Active Antenna
LNA
external
antenna
voltage
supply
Antenna
Supervisor
Circuitry
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".
Disable Supervision
No
Super-
Enable Supervision
vision
Antenna
connected
Disable
Supervision
open circuit
detected, given
OCD enabled
Open
Circuit
Short Circuit
detected
detected
Figure 35: State diagram of active antenna supervisor
GPS.G5-MS5-09027-A2
GND
RF_IN
GND
VCC_RF
V_ANT
AADET_N
Powerup
Events AADET0_N
Active
Antenna
User controlled events
OK
Periodic
Short Circuit
reconnection
detected
attempts
Short
Circuit
detected
Released
LEA-5, NEO-5, TIM-5H - Hardware Integration Manual
u-blox 5 Module
Design-in
Page 42 of 68