Re: Large inductors in GPS supply and data lines ?

Graham, VE3GTC
 

In the uBlox hardware integration manuals a recommended practice is to use a ferrite bead, inductor, or small value resistor to help mitigate noise.

The idea is to slow down a bit the rising and falling edges of the digital signals.

quote: "On the other hand, noise generated at the I/O pins will emit from unshielded I/O lines. Receiver performance may be degraded when this noise is coupled into the GNSS antenna (see Figure 14). To avoid interference by improperly shielded lines, it is recommended to use resistors (e.g. R>20 Ω), ferrite beads (e.g. BLM15HD102SN1) or inductors (e.g. LQG15HS47NJ02) on the I/O lines in series. These components should be chosen with care because they will affect also the signal rise times"

LQG15HS47NJ02 is 47nH

https://www.u-blox.com/sites/default/files/NEO-8Q-NEO-M8-FW3_HardwareIntegrationManual_%28UBX-15029985%29_0.pdf

cheers, Graham ve3gtc


On 2019-06-20 19:32, Richard G4TGJ wrote:
At 9.6kHz 470mH is about 28k ohm.
--
73
Richard
G4TGJ

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