LEA-5, NEO-5, TIM-5H - Hardware Integration Manual
GPS.G5-MS5-09027-A2
Released
Design-in
Page 47 of 68
Small passive antennas
(<2 dBic
and performance critical)
Passive antennas
(>2 dBic or
performance sufficient)
Active Antennas
A
RF
_
IN
G
P
S
R
e
c
e
iv
e
r
LNA
B
L
RF
_
IN
G
P
S
R
e
c
e
iv
e
r
C
D
RF
_
IN
G
P
S
R
e
c
e
iv
e
r
LNA with appropriate ESD rating
Figure 38: ESD Precautions
Protection measure A is preferred due to performance and protection level considerations.
2.7.4
Electrical Overstress (EOS)
Electrical Overstress (EOS) usually describes situations when the maximum input power exceeds the maximum
specified ratings. EOS failure can happen if RF emitters are close to a GPS receiver or its antenna. EOS causes
damage to the chip structures.
If the RF_IN is damaged by EOS, it‖s hard to determine whether the chip structures have been damaged by ESD
or EOS.
2.7.5
EOS protection measures
EOS protection measures as shown in Figure 39 are recommended for any designs combining wireless
communication transceivers (e.g. GSM, GPRS) and GPS in the same design or in close proximity.
Small
passive
antennas
(<2 dBic
and
performance
critical)
Passive antennas
(>2 dBic or
performance sufficient)
Active Antennas
(without internal filter
which need the module antenna supervisor
circuits)
D
RF
_
IN
G
P
S
R
e
c
e
iv
e
r
LNA
GPS
Bandpass
Filtler
E
RF
_
IN
G
P
S
R
e
c
e
iv
e
r
L
GPS
Bandpass
Filtler
F
RF
_
IN
G
P
S
R
e
c
e
iv
e
r
L
GPS
Bandpass
Filtler
C
C
L
L
LNA with appropriate ESD
rating and maximum input
power
GPS Bandpass Filter: SAW or
Ceramic with low insertion loss
and appropriate ESD rating
Figure 39: EOS and ESD Precautions
2.7.6
Electromagnetic interference (EMI)
Electromagnetic interference (EMI) is the addition or coupling of energy released from any RF emitting device.
This can cause a spontaneous reset of the GPS receiver or result in unstable performance. Any unshielded line or
