2 posts / 0 new
Last post
Last seen: 6 years 1 week ago
Joined: 2014-01-08 06:00
R79 (10ohm) in Mother Rev.C2

What is the effect of R79 mounted on the mother board?
Spike noise filter for Power Profile in Smart Snippets?

Last seen: 11 months 3 weeks ago
Joined: 2013-12-05 14:02
Hello Yamazaki,

Hello Yamazaki,
The 10 Ohm resistor function is to simulate the coin-cell battery voltage drop which typically is about 50 mV for 5 mA supply current.

This 10R will cause a voltage drop of 50 mV for 5 mA Rx Tx peak currents. For having this supply voltage drop, J24 has to be removed.
When supplying from the LDO @ 1.5V (J23 open) the jumper J24 should be placed since the voltage drop from the 1.5V battery is much lower.

Normally we test with J24 always placed.

Best Regards,