GSM/GPRS/NB-IoT Module Series
BC68&M66 Compatible Design
BC68&M66_Compatible_Design 14 / 31
4
Hardware Reference Design
The following chapters describe the compatible design between BC68 and M66 on main functionalities.
4.1. Power Supply
4.1.1. Reference Design for Power Supply
The power design for the module is very important, as the performance of a module largely depends on
the power source. The power supply for BC68 and M66 should be able to provide sufficient current up to
2A.
A TVS diode needs to be added on the VBAT trace to increase surge voltage withstand capability. The
following figure shows a reference design for battery power supply and the designed output of the power
supply is about 3.6V.
Battery
OUT
GND
VBAT
C1
470uF
C2
1uF
TVS
Figure 2: Reference Circuit of Power Supply
4.1.2. Reduce Voltage Drop
The power supply range of BC68 is from 3.1V to 4.2V. The power supply range of M66 is 3.3V to 4.6V
Attention should be paid to the range of the power source to make sure that the input voltage will never
drop below 3.3V and never exceed 4.2V. In addition, in order to get a stable output voltage, a TVS diode
also needs to be added on the VBAT trace to increase surge voltage withstand capability.
