LEA-6 / NEO-6 / MAX-6 - Hardware Integration Manual
UBX-14054794
Production Information
Design-in
Page 47 of 85
References
Value
Tolerance
Description
Remarks
R1
10
5%
Resistor, min 0.250 W
R2
560
5%
Resistor
R3
100 k
5%
Resistor
U1
LT6000
Rail to Rail Op Amp
Linear Technology
Table 18: Active antenna supervisor, bill of material
RF
Vcc
R
R
R
R
I
_
1
3
2
2
Equation 1: Calculation of threshold current for open circuit detection
If the antenna supply voltage is not derived from Vcc_RF, do not exceed the maximum voltage rating of
AADET_N.
The open circuit detection circuit uses the current flow to detect an open circuit in the antenna. The threshold
current can be calculated using Equation 1.
GND
RF_IN
GND
V_ANT
VCC_RF
Active Antenna
ADDET_N
V_ANT
Antenna
Supply in
Analog GND
R1
R2
R3
R4
R5
T2
PNP
T1
PNP
C1
C2
FB1
AADET_N
LEA-6x
Figure 47: Schematic of open circuit detection variant B (for exact pin orientation see data sheet)
The open circuit supervisor circuitry shown in Figure 47 has a quiescent current of approximately 2mA.
This current can be reduced with an advanced circuitry such as shown in Figure 47.