User's Manual
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 UICC/SIM/USIM Interface
- 2.1.7 Digital Audio Interface
- 2.1.8 Pulse Code Modulation Interface (PCM)
- 2.1.9 Inter IC Sound Interface (I2S)
- 2.1.10 GPIO Interface
- 2.1.11 I2C Interface
- 2.1.12 SPI Interface
- 2.1.13 Pulse Counter
- 2.1.14 HSIC Interface (ELS51-VA Only)
- 2.1.15 SDIO Interface (ELS51-VA Only)
- 2.1.16 Control Signals
- 2.2 RF Antenna Interface
- 2.3 Sample Application
- 2.1 Application Interface
- 3 Operating Characteristics
- 3.1 Operating Modes
- 3.2 Power Up/Power Down Scenarios
- 3.3 Power Saving
- 3.4 Power Supply
- 3.5 Operating Temperatures
- 3.6 Electrostatic Discharge
- 3.7 Blocking against RF on Interface Lines
- 3.8 Reliability Characteristics
- 4 Mechanical Dimensions, Mounting and Packaging
- 5 Regulatory and Type Approval Information
- 6 Document Information
- 7 Appendix
Cinterion
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ELS31-VA/ELS51-VA Hardware Interface Description
3.4 Power Supply
76
ELS31-VA_ELS51-VA_HID_v01.000 2017-01-04
Confidential / Preliminary
Page 70 of 106
3.4.2 Minimizing Power Losses
When designing the power supply for your application please pay specific attention to power
losses. Ensure that the input voltage of BATT_BB/BATT_RF never drops below 3.3V on the
ELS31-VA/ELS51-VA board.
3.4.3 Measuring the Supply Voltage (BATT_BB)
To measure the supply voltage of BATT_BB/BATT_RF it is possible to define three reference
points GND ,BATT_BB and BATT_RF. GND should be the module’s shielding, while BAT-
T_BB/BATT_RF should be a test pad on the external application the module is mounted on.
The external BATT_BB/NBATT_RF reference points have to be connected to and positioned
close to the SMT application interface’s BATT pads 5 (BATT_BB) or 53 (BATT_RF) as shown
in Figure 37.
Figure 37: Position of reference points BATT_BB/BATT_RF and GND
3.4.4 Monitoring Power Supply by AT Command
To monitor the supply voltage you can also use the AT^SBV command which returns the value
related to the reference points BATT_BB and GND.
The module continuously measures the voltage at intervals depending on the operating mode
of the RF interface. The duration of measuring ranges from 0.5 seconds in TALK/DATA mode
to 50 seconds when ELS31-VA/ELS51-VA is in IDLE mode or Limited Service (deregistered).
The displayed voltage (in mV) is averaged over the last measuring period before the AT^SBV
command was executed.
If the measured voltage drops below or rises above the voltage shutdown thresholds, the mod-
ule will send an "^SBC" URC and shut down (for details see Section 3.2.5).
Reference point GND:
Module shielding
Reference point BATT_BB/
BATT_RF:
External test pad connected
to and positioned closely to
BATT pad 5 or 53.
External application