EVK-R4 - User guide

UBX-16029216 - R08

Appendix

Page 27 of 31

C1-Public

D.2 EVK-R422M8S

The current consumption of the SARA-R422M8S modules can be measured on the EVK-R4 by

removing the jumper socket from the Cellular VCC supply jumper J109 available on the ADP-R4, as

illustrated in Figure 12.

Cellular VCC supply jumper socket (J109)

to be removed for SARA-R422M8Smodule

current consumption measurements

Figure 12: Jumper socket to be removed for SARA-R422M8S modules current consumption measurement

A suitable external digital multi-meter (as the Keysight 34465A, 34410A or 34411A) can be used for

current consumption measurements. In this case, the 3.8 V supply circuit on the EVB will supply the

SARA-R4 module, with the digital multi-meter placed in series, as illustrated in Figure 13.

SARA-R4 adapter board

SARA-R4

Cellular

module

EVB-WL3

Step - down

Main power switch

(SW400)

12 V

(J400)

3.8 V

VCC jumper

(J109)

VCC

Digital multimeter

DCI

+

–

VCC jumper

(J404)

Figure 13: Block diagram of current consumption setup for SARA-R422M8S modules

Alternatively, a suitable external DC power supply with the dynamic current measurement capabilities

(as for example, the portable and cheap Qoitech Otii Arc, or the more accurate Keysight N6705B, or

the models designed for mobile communications Keysight 66319B/D or 66321B/D) can be used for

current consumption measurements, acting also as the 3.8 V supply source for the SARA-R4 module

mounted on the adapter board, as illustrated in Figure 14.

SARA-R4 adapter board

SARA-R4

Cellular

module

EVB-WL3

Step - down

Main power switch

(SW400)

12 V

(J400)

3.8 V

VCC jumper

(J109)

VCC

Power analyzer

PSU

VCC jumper

(J404)

+

GND

GND

Figure 14: Block diagram of current consumption setup for SARA-R422M8S using a DC power analyzer