SAMC21 datasheet(43/46 Pages) ATMEL

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6.4.

Revision 3

Revision 3 is almost identical to revision 2 with an additional quick fix for the 3.3V target supply problem.

The fix is implemented by shorting Q102, pin 2 to GND as shown in the figure below. Also the QTouch

pad is connected inside the PCB.

Figure 6-5. Strap Fix

Related Links

The QTouch Button PAD is not Connected on page 43

Kit Does Not Work with 3.3V Target Voltage Selected on page 43

6.5.

Revision 2

Revision 2 is the initial released revision. This revision has engineering samples mounted with part

number ATSAMC21J18A-AUTES.

6.5.1.

The QTouch Button PAD is not Connected

On Revision 2 of the kit, the QTouch button PAD is not connected to the track inside the PCB. This will

cause the QTouch function to work only on the VIA connection point. There is no workaround for this

issue. This will be fixed in next revision of the PCB.

6.5.2.

Kit Does Not Work with 3.3V Target Voltage Selected

Revision 2 of the kit has a start-up problem when target voltage is set to 3.3V. When the EDBG opens the

target voltage power switch from VCC_TARGET_SWITCH_P3V3_P5V0 to VCC_TARGET_P3V3_P5V0 a

power surge is observed. This power surge causes the VCC_P3V3 nets voltage to decrease enough to

trigger the EDBGs BOD, resulting in the EDBG entering a locked state where it can not be used.

Fix/Workaround:

Use the kit with 5.0V selected as the target voltage.

Force the target voltage switch open by connecting Q102 pin 2 to GND.

Important: Forcing the target voltage switch open will disable any protection for Xplained Pro

extension modules connected to EXT1, EXT2, and EXT3. Make sure that connected extensions

supports the selected target voltage.

SAMC21 Scheda tecnica(PDF) 43 Page - ATMEL Corporation