Specifications
Table Of Contents
- Contents
- Tables
- Figures
- 1 Introduction
- 2 Interface Characteristics
- 2.1 Application Interface
- 2.1.1 Pad Assignment
- 2.1.2 Signal Properties
- 2.1.3 USB Interface
- 2.1.4 Serial Interface ASC0
- 2.1.5 Serial Interface ASC1
- 2.1.6 Inter-Integrated Circuit Interface
- 2.1.7 UICC/SIM/USIM Interface
- 2.1.8 Enhanced ESD Protection for SIM Interfaces
- 2.1.9 Digital Audio Interface
- 2.1.10 Analog-to-Digital Converter (ADC)
- 2.1.11 RTC Backup
- 2.1.12 GPIO Interface
- 2.1.13 Control Signals
- 2.1.14 JTAG Interface
- 2.1.15 eMMC Interface
- 2.2 GSM/UMTS/LTE Antenna Interface
- 2.3 GNSS Antenna Interface
- 2.4 Sample Application
- 2.1 Application Interface
- 3 GNSS Interface
- 4 Operating Characteristics
- 5 Mechanical Dimensions and Mounting
- 6 Regulatory and Type Approval Information
- 7 Document Information
- 8 Appendix
Cinterion
®
ALAS5V Hardware Interface Description
2.2 GSM/UMTS/LTE Antenna Interface
67
ALAS5V_HID_v00.030a 2019-03-20
Confidential / Preliminary
Page 55 of 124
Table 15 lists assured antenna diagnostic states depending on the measured R
ANT
values. Note
that the R
ANT
ranges not mentioned in the below table, i.e., 1k...6k and 12k...40k are tol-
erance ranges. Within these tolerance ranges a decision threshold for a diagnostic application
may be located. For more details on the sample antenna detection circuit please refer to Sec-
tion 2.3.1.
Measuring procedure for the basic circuit given in Figure 21:
The battery current flows through R1 and RA. The voltage drop on RA is divided by R3/(R3+R2)
and measured by the ADCx_IN input. For the ADCx_IN voltage V
ADCx
(monitored using
AT^SRADC) and the BATT+ supply voltage V
BATT+
(monitored using AT^SBV) several measur-
ing samples should be taken for averaging. The measured and averaged value V
ADCx
will then
be compared to three decision thresholds. The decision thresholds depend on BATT+:
Table 15: Assured antenna diagnostic states
Antenna state R
ANT
range
Normal operation, antenna connected (resistance at feed
point as required)
R
ANT
= 6k…12k
Antenna pad short-circuited to GND R
ANT
= 0…1k
Antenna not properly connected, or resistance at antenna
feed point wrong or not present
R
ANT
= 40k…
Antenna pad is short-circuited to the supply voltage of the
host application, for example the vehicle’s on-board power
supply voltage
max. 36V
Table 16: GSM/UMTS/LTE antenna diagnostic decision threshold
Decision threshold
1
1. The decision thresholds depends on BATT+ and has to be calculated separately for each decision (the
BATT+ voltage level V
BATT+
is known to the system: 3.3V < V
BATT+
< 4.2V).
V
ADCx
Result
Short to GND Appr. 0,176*V
BATT+
(580mV…738mV)
Short-circuited to ground
Antenna connected
No antenna Appr. 0,337*V
BATT+
(1111mV…1414mV)
> Antenna nor properly connected
Short to power 0.146+0.405*V
BATT+
(1482mV…1888mV)
<
> Short-circuited to power