Power Supply; Decrease Voltage Drop - Quectel 5G Module Series Hardware Design

3.3. Power Supply

The following table shows pin definition of VCC pins and ground pins.
Table 7: Definition of VCC and GND Pins
Pin
2, 4, 70, 72, 74
3, 5, 11, 27, 33, 39, 45,
51, 57, 71, 73

3.3.1. Decrease Voltage Drop

The power supply range of the module is from 3.135 V to 4.4 V. Please ensure that the input voltage will
never drop below 3.135 V, otherwise the module will be powered off automatically. The voltage ripple of
the input power supply should be less than 100 mV, and the voltage drop should be less than 165 mV.
VCC 3.7 V
Voltage Drop < 165 mV
Figure 5: Power Supply Limits during Radio Transmission
Ensure the continuous current capability of the power supply is 3.0 A. To decrease the voltage drop, two
bypass capacitor of about 220 µF with low ESR (ESR = 0.7 Ω) should be used. To decrease the power
supply is disturbed, a multi-layer ceramic chip capacitor (MLCC) array also should be used due to its
ultra-low ESR. It is recommended to use four ceramic capacitors (1 µF, 100 nF, 33 pF, 10 pF) for
composing the MLCC array, and place these capacitors close to VCC pins. The width of VCC trace
should be no less than 2.5 mm. In principle, the longer the VCC trace is, the wider it should be.
In addition, to get a stable power source, it is recommended to use a zener diode with reverse zener
voltage of 5.1 V and dissipation power of more than 0.5 W.
RM500Q-AE&RM502Q-AE_Hardware_Design
Pin Name I/O
VCC PI
GND
Burst Transmission
RM500Q-AE&RM502Q-AE Hardware Design
Description DC Characteristics
3.135–4.4 V
Power supply
3.7 V typical DC supply
Ground
Burst Transmission
5G Module Series
Voltage Ripple
< 100 mV
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