Quectel BC66 - USB Interface

NB-IoT Module Series
BC66 Hardware Design
BC66_Hardware_Design 21 / 59
1. Among all GPIO interrupts, only the dedicated external interrupt pin PSM_EINT can successfully
wake up the module from Deep Sleep. Other general-purpose GPIO interrupts cannot wake up the
module from Deep Sleep.
2. When eDRX cycle exceeds 82s, the module will enter Deep Sleep mode after the PTW length while
the AP can remain in idle mode.
3. When AT+CFUN=0, the module will enter Deep Sleep mode while the AP can remain in idle mode.
4. In OOS stage (default searching intervals: 5s/10s/10s/1s/120s/7200s/7200s/…), the module enters
Deep Sleep mode only when searching interval exceeds 120s and the AP can remain in idle mode.
3.6. Power Supply
3.6.1. Power Supply Pins
BC66 provides two VBAT pins for connection with an external power supply. The table below describes
the module's VBAT and ground pins.
Table 8: Power Supply Pins
Pin Name
Pin No.
Description
Min.
Typ.
Max.
Unit
VBAT_BB
42
Power supply for the
module’s baseband
part
2.1
3.3
3.63
V
VBAT_RF
43
Power supply for the
module’s RF part
2.1
3.3
3.63
V
GND
1, 27, 34,
36, 37, 40, 41
GND
3.6.2. Reference Design for Power Supply
Power design for a module is critical to its performance. It is recommended to use a low quiescent current
LDO with output current capacity of 0.5A as the power supply for BC66. Alkaline batteries can also be
used as the power supply. The supply voltage of the module ranges from 2.1V to 3.63V. When the module
is working, please make sure its input voltage will never drop below 2.1V; otherwise the module will be
abnormal.
For better power performance, it is recommended to place a 100μF tantalum capacitor with low ESR
(ESR=0.7Ω) and three ceramic capacitors (100nF, 100pF and 22pF) near the VBAT pins. Also, it is
recommended to add a TVS diode on the VBAT trace (near VBAT pins) to improve surge voltage
NOTES