Datasheet
Table Of Contents
- Document Information
- Contents
- 1 Functional description
- 2 Interfaces
- 3 Pin definition
- 4 Electrical specifications
- 4.1 Absolute maximum rating
- 4.2 Operating conditions
- 4.2.1 Operating temperature range
- 4.2.2 Supply/power pins
- 4.2.3 Current consumption
- 4.2.4 LTE RF characteristics
- 4.2.5 3G RF characteristics
- 4.2.6 2G RF characteristics
- 4.2.7 ANT_DET pin
- 4.2.8 PWR_ON pin
- 4.2.9 RESET_N pin
- 4.2.10 SIM pins
- 4.2.11 USB pins
- 4.2.12 HSIC pins
- 4.2.13 DDC (I2C) pins
- 4.2.14 Generic Digital Interfaces pins
- 5 Mechanical specifications
- 6 Qualification and approvals
- 7 Product handling & soldering
- 8 Default settings
- 9 Labeling and ordering information
- Appendix
- A Glossary
- Related documents
- Revision history
- Contact
LARA-R2 series - Data Sheet
UBX-16005783 - R15 Interfaces Page 11 of 48
2 Interfaces
2.1 Power management
2.1.1 Module supply input (VCC)
LARA-R2 series modules must be supplied through the three VCC pins by a DC power supply. Voltage
must be stable, because during operation the current drawn from VCC can vary by some order of
magnitude, especially due to the surging consumption profile of the GSM system (described in the
LARA-R2 series System Integration Manual [2]). It is important that the system power supply circuit
is able to support peak power.
LARA-R211 modules provide separate supply inputs over the three VCC pins:
VCC pins #52 and #53 represent the supply input for the internal RF power amplifier, demanding
most of the total current drawn of the module when RF transmission is enabled during a
voice/data call
VCC pin #51 represents the supply input for the internal baseband Power Management Unit and
the internal transceiver, demanding a minor part of the total current drawn of the module when
RF transmission is enabled during a voice/data call
2.1.2 RTC supply input / output (V_BCKP)
When VCC voltage is within the valid operating range, the internal Power Management Unit (PMU)
supplies the Real Time Clock (RTC) and the same supply voltage is available on the V_BCKP pin. If the
VCC voltage is under the minimum operating limit (e.g. during not powered mode), the V_BCKP pin
can externally supply the RTC.
2.1.3 Generic digital interfaces supply output (V_INT)
LARA-R2 series modules provide a 1.8 V supply rail output on the V_INT pin, which is internally
generated when the module is switched on. The same voltage domain is used internally to supply the
generic digital interfaces of the modules. The V_INT supply output can be used in place of an external
discrete regulator.
2.2 Antenna interfaces
2.2.1 Antenna RF interfaces
The modules have two RF pins with a characteristic impedance of 50 . The primary antenna pin
(ANT1) supports both Tx and Rx, providing the main antenna interface, while the secondary antenna
pin (ANT2) supports Rx only for the LTE / 3G Rx diversity configuration.
2.2.2 Antenna detection
The ANT_DET pin is an Analog to Digital Converter (ADC) input with a current source provided by
LARA-R2 modules to sense the antenna(s) presence (as an optional feature). It evaluates the
resistance from ANT1 and ANT2 pins to GND by means of an external antenna detection circuit
implemented on the application board. For more details, see the LARA-R2 series System Integration
Manual [2] and the u-blox AT Commands Manual [1].