NEO-D9C - Integration manual
4.3 Power supply
The u-blox NEO-D9C module has two power supply pins: VCC and V_USB.
4.3.1 VCC: Main supply voltage
The
VCC
pin is connected to the main supply voltage. During operation, the current drawn by the
module can vary by some orders of magnitude. For this reason, it is important that the supply
circuitry be able to support the peak power for a short time (see the applicable data sheet [
] for
specification).
To reduce peak current during power on, users can employ an LDO that has an in-built
current limiter.
Do not add any series resistance greater than 0.2
Ω
to the VCC supply as it will generate
input voltage noise due to dynamic current conditions.
For the NEO-D9C module the equipment must be supplied by an external limited power
source in compliance with the clause 2.5 of the standard IEC 60950-1.
4.3.2 NEO-D9C power supply
The NEO-D9C requires a low-noise, low-dropout voltage, and a very low source impedance power
supply of 3.3 V typically. No inductors or ferrite beads should be used from LDO to the module
VCC pin. The peak currents need to be taken into account for the source supplying the LDO for the
module.
A power supply fed by 5 V is shown in the figure below. This example circuit is intended only for the
module supply.
Figure 25: NEO-D9C power supply
4.4 NEO-D9C minimal design
The minimal electrical circuit for NEO-D9C operation using the UART1 interface is shown below:
UBX-21031631 - R02
4 Design
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