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
3.3 Power Saving
76
ELS31-VA_ELS51-VA_HID_v01.000 2017-01-04
Confidential / Preliminary
Page 66 of 106
3.3 Power Saving
ELS31-VA/ELS51-VA can be configured in two ways to control power consumption:
• Being set by configuration, it is possible to specify a so-called power saving mode for the
module (for details on the command see [1]). The module's UART interfaces (ASC0 and
ASC1) are then deactivated and will only periodically be activated to be able to listen to net-
work paging messages as described in Section 3.3.1. See Section 3.3.2 for a description
of how to immediately wake up ELS31-VA/ELS51-VA again using RTS0.
Note: RTS0/RTS1 must to be set to high before the ELS31-VA/ELS51-VA can change into
power saving mode. Also note that the AT^SPOW setting has no effect on the USB inter-
face. As long as the USB connection is active, the module will not change into its SLEEP
state to reduce its functionality to a minimum and thus minimizing its current consumption.
To enable switching into SLEEP mode, the USB connection must therefore either not be
present at all or the USB host must bring its USB interface into Suspend state. Also, VUS-
B_IN should always be kept enabled for this functionality. See “Universal Serial Bus Spec-
ification Revision 2.0”
1
for a description of the Suspend state.
• Being triggered by LTE network protocol while attached to LTE networks
3.3.1 Power Saving while Attached to LTE Networks
The power saving possibilities while attached to a LTE network depend on the paging timing
cycle of the base station.
During normal LTE operation, i.e., the module is connected to a LTE network, the duration of
a power saving period varies. It may be calculated using the following formula:
t = DRX Cycle Value* 10 ms
DRX (Discontinuous Reception) value in LTE networks is any of the four values: 32, 64, 128
and 256, thus resulting in power saving intervals between 0.32 and 2.56 seconds. The DRX
value of the base station is assigned by the LTE network operator.
In the pauses between listening to paging messages, the module resumes power saving, as
shown in Figure 35.
Figure 35: Power saving and paging in LTE networks
The varying pauses explain the different potential for power saving. The longer the pause the
less power is consumed.
Generally, power saving depends on the module’s application scenario and may differ from the
above mentioned normal operation. The power saving interval may be shorter than 0.64 sec-
onds or longer than 5.12 seconds.
1. The specification is ready for download on http://www.usb.org/developers/docs/
Power SavingPaging
DRX Cycle
0.32 - 2.56s
Power SavingPaging
DRX Cycle
0.32 - 2.56s
Power SavingPaging
DRX Cycle
0.32 - 2.56s
Power SavingPaging
DRX Cycle
0.32 - 2.56s