Power Supply; Decrease Voltage Drop - Quectel RM520N-GL Hardware Design

Note that if the host does not support firmware upgrade through PCIe, the firmware can be upgraded by
the 5G-M2 EVB, which could be connected to PC with a USB type-B cable. For more details, see
document [2].

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 when 3.3 V power supply is applied, as shown by
the following figure
VCC
Voltage Drop
3.135 V
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 capacitors of 220 µF with low ESR should be used, and a multi-layer ceramic chip capacitor
(MLCC) array should also be used due to its ultra-low ESR. It is recommended to use ceramic capacitors
(100 nF, 6.8 nF, 220 pF, 68 pF, 15 pF, 9.1 pF, 4.7 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.
RM520N-GL_Hardware_Design
Pin Name I/O
VCC PI
GND
Burst Transmission
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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