Product Info
Table Of Contents
- About the Document
- Contents
- Table Index
- Figure Index
- 1 Introduction
- 2 Product Concept
- 3 Application Interfaces
- 3.1. General Description
- 3.2. Pin Assignment
- 3.3. Pin Description
- 3.4. Power Supply
- 3.5. Turn on and off Scenarios
- 3.6. VRTC Interface
- 3.7. Power Output
- 3.8. Battery Charge and Management
- 3.9. USB Interfaces
- 3.10. UART Interfaces
- 3.11. (U)SIM Interfaces
- 3.12. SD Card Interface
- 3.13. GPIO Interfaces
- 3.14. I2C Interfaces
- 3.15. I2S Interfaces
- 3.16. SPI Interface
- 3.17. ADC Interfaces
- 3.18. LCM Interfaces
- 3.19. Touch Panel Interfaces
- 3.20. Camera Interfaces
- 3.21. Sensor Interfaces
- 3.22. Audio Interfaces
- 3.23. Emergency Download Interface
- 4 Wi-Fi and BT
- 5 GNSS
- 6 Antenna Interfaces
- 7 Electrical, Reliability and Radio Characteristics
- 8 Mechanical Dimensions
- 9 Storage, Manufacturing and Packaging
- 10 Appendix A References
- 11 Appendix B GPRS Coding Schemes
- 12 Appendix C GPRS Multi-slot Classes
- 13 Appendix D EDGE Modulation and Coding Schemes
- IC & FCC Requirement
Smart LTE Module Series
SC66 Hardware Design
SC66_Hardware_Design 50 / 139
Constant current mode (CC mode): When the battery voltage is increased to between the
maximum pre-charge voltage and 4.35V (3.6V~4.5V programmable, 4.35V by default), the system
will switch to CC mode. The charging current is programmable from 0mA~3000mA. The default
charging current is 500mA for USB charging and 2A for adapter.
Constant voltage mode (CV mode): When the battery voltage reaches the final value 4.35V, the
system will switch to CV mode and the charging current will decrease gradually. When the charging
current reduces to about 100mA, the charging is completed.
Table 11: Pin Definition of Charging Interface
Pin Name Pin No. I/O Description Comment
USB_VBUS 41, 42 PI/PO
Charging power input.
Power supply output for OTG device.
USB/charger insertion detection.
Vmax=10V
Vmin=3.6V
Vnorm=5.0V
VBAT
36, 37,
38
PI/PO Power supply for the module
Vmax=4.4V
Vmin=3.55V
Vnorm=4.0V
BAT_PLUS 27 AI
Differential input signal of battery voltage
detection (+)
Must be connected
BAT_MINUS 28 AI
Differential input signal of battery voltage
detection (-)
Must be connected
BAT_THERM 29 AI Battery temperature detection
Internally pulled up.
Externally connected
to GND via a 47KΩ
NTC resistor.
SC66 module supports battery temperature detection in the condition that the battery integrates a
thermistor (47K 1% NTC thermistor with B-constant of 4050K by default; SDNT1608X473F4050FTF of
SUNLORD is recommended) and the thermistor is connected to VBAT_THERM pin. If VBAT_THERM pin
is not connected, there will be malfunctions such as boot error, battery charging failure, battery level
display error, etc.
A reference design for battery charging circuit is shown below.