Integration Manual
Table Of Contents
- Contents
- 1 System description
- 1.1 Overview
- 1.2 Architecture
- 1.3 Pin-out
- 1.4 Operating modes
- 1.5 Supply interfaces
- 1.5.1 Module supply input (VCC)
- 1.5.1.1 VCC supply requirements
- 1.5.1.2 VCC current consumption in 2G connected mode
- 1.5.1.3 VCC current consumption in 3G connected mode
- 1.5.1.4 VCC current consumption in LTE connected mode
- 1.5.1.5 VCC current consumption in cyclic low power idle mode / active mode
- 1.5.1.6 VCC current consumption in fixed active mode
- 1.5.2 Generic digital interfaces supply output (V_INT)
- 1.5.1 Module supply input (VCC)
- 1.6 System function interfaces
- 1.7 Antenna interfaces
- 1.8 SIM interfaces
- 1.9 Data communication interfaces
- 1.10 eMMC interface
- 1.11 Digital Audio interfaces
- 1.12 ADC interfaces
- 1.13 General Purpose Input/Output
- 1.14 Reserved pins (RSVD)
- 1.15 System features
- 1.15.1 Network indication
- 1.15.2 Jamming detection
- 1.15.3 IP modes of operation
- 1.15.4 Dual stack IPv4 and IPv6
- 1.15.5 Embedded TCP/IP and UDP/IP
- 1.15.6 Embedded FTP and FTPS
- 1.15.7 Embedded HTTP and HTTPS
- 1.15.8 SSL and TLS
- 1.15.9 Firmware update Over AT (FOAT)
- 1.15.10 Firmware update Over The Air (FOTA)
- 1.15.11 Power Saving
- 2 Design-in
- 2.1 Overview
- 2.2 Supply interfaces
- 2.2.1 Module supply (VCC)
- 2.2.1.1 General guidelines for VCC supply circuit selection and design
- 2.2.1.2 Guidelines for VCC supply circuit design using a switching regulator
- 2.2.1.3 Guidelines for VCC supply circuit design using a LDO linear regulator
- 2.2.1.4 Guidelines for VCC supply circuit design using a rechargeable battery
- 2.2.1.5 Guidelines for VCC supply circuit design using a primary battery
- 2.2.1.6 Additional guidelines for VCC supply circuit design
- 2.2.1.7 Guidelines for the external battery charging circuit
- 2.2.1.8 Guidelines for external charging and power path management circuit
- 2.2.1.9 Guidelines for removing VCC supply
- 2.2.1.10 Guidelines for VCC supply layout design
- 2.2.1.11 Guidelines for grounding layout design
- 2.2.2 Generic digital interfaces supply output (V_INT)
- 2.2.1 Module supply (VCC)
- 2.3 System functions interfaces
- 2.4 Antenna interface
- 2.5 SIM interfaces
- 2.6 Data communication interfaces
- 2.7 eMMC interface
- 2.8 Digital Audio interface
- 2.9 ADC interfaces
- 2.10 General Purpose Input/Output
- 2.11 Reserved pins (RSVD)
- 2.12 Module placement
- 2.13 Module footprint and paste mask
- 2.14 Thermal guidelines
- 2.15 Design-in checklist
- 3 Handling and soldering
- 4 Approvals
- 5 Product testing
- 6 FCC Notes
- Appendix
- Glossary
- Related documents
- Revision history
- Contact
TOBY-L3 series - System Integration Manual
TSD-19090601 - R13 System Integration Manual Page 64 of 143
The usage of more than one DC supply at the same time should be evaluated carefully: depending on the
supply source characteristics, different DC supply systems can result as mutually exclusive.
The usage of a regulator or a battery not able to support the highest peak of VCC current consumption
specified in the TOBY-L3 series Data Sheet [1] is generally not recommended. However, if the selected
regulator or battery is not able to support the highest peak current of the module, it must be able to
support with adequate margin at least the highest averaged current consumption value specified in the
TOBY-L3 series Data Sheet [1]. The additional energy required by the module during a 2G Tx slot can be
provided by an appropriate bypass tank capacitor or a super-capacitor with very large capacitance and very
low ESR placed close to the module VCC pins. Depending on the actual capability of the selected regulator
or battery, the required capacitance can be considerably larger than 1 mF and the required ESR can be in
the range of few tens of m. Carefully evaluate the super-capacitor characteristics since aging and
temperature may affect the actual characteristics.
The following sections highlight some design aspects for each of the supplies listed above providing
application circuit design-in compliant with the module VCC requirements summarized in Table 7.
2.2.1.2 Guidelines for VCC supply circuit design using a switching regulator
The use of a switching DC/DC regulator is suggested when the difference from the available supply rail
source to the VCC value is high, since switching regulators provide good efficiency transforming a 12 V or
greater voltage supply to the typical 3.8 V value of the VCC supply.
The characteristics of the switching regulator connected to VCC pins should meet the following prerequisites
to comply with the module VCC requirements summarized in Table 7:
Power capability: the switching regulator with its output circuit must be capable of providing a voltage
value to the VCC pins within the specified operating range and must be capable of delivering to VCC
pins the maximum peak / pulse current consumption during Tx burst at maximum Tx power specified in
the TOBY-L3 series Data Sheet [1].
Low output ripple: the switching regulator together with its output circuit must be capable of providing
a clean (low noise) VCC voltage profile.
High switching frequency: for best performance and for smaller applications it is recommended to
select a switching frequency ≥ 600 kHz (since L-C output filter is typically smaller for high switching
frequency). The use of a switching regulator with a variable switching frequency or with a switching
frequency lower than 600 kHz must be evaluated carefully since this can produce noise in VCC voltage
profile and thus negatively impact modulation spectrum figure. An additional L-C low-pass filter between
the switching regulator output to VCC supply pins can mitigate the ripple at the input of the module,
but adds extra voltage drop due to resistive losses on series inductors.