3 Board Setup Details
3.1 Power Supply Selection
Dual Supply Mode vs. Triple Supply Mode
The DP83561-SP can be powered by as few as two supplies in dual supply mode, or three supplies in triple
supply mode. In dual supply mode, the VDDA1P8 pin must be left floating. By default the DP83561EVM is
configured for dual supply mode. To configure the DP83561-SP in triple supply mode:
• Place shunt on J37 to enable the SUPPLYMODE_SEL strap as described in
The following sections describe powering the DP83561EVM using the on-board LDOs, external supplies, or USB
power. Please note that powering the VDDA1P8 pin is only required in triple supply Mode.
3.1.1 VDDIO Selection
In addition to supplying the correct voltage, the DP83561-SP uses straps to select VDDIO levels. If 2.5 V is used
as the VDDIO level, the VDDIOSEL_1 strap must be pulled high, which can be done by placing a shunt on J35.
If 1.8 V is used asthe VDDIO level, both the VDDIOSEL_1 and VDDIOSEL_0 straps must be pulled high, by
placing shunts on J35 and J36. For a VDDIO level of 3.3 V, these pins can be left floating.
Table 3-1. VDDIO Selection Strap Settings
Strap
VDDIO Level
VDDIOSEL_1
VDDIOSEL_0
0
0
3.3 V
0
1
Reserved
1
0
2.5 V
1
1
1.8 V
Figure 3-1. DP83561EVM VDDIO Selection Straps
3.1.2 On-board Power Supply Operation
• DP83561EVM Onboard Power Using Headers
– Place shunt at J23 to connect VDDA1P8 LDO (triple supply mode only)
– Place shunt at J20 to connect VDDA2P5 LDO
– Place shunt at P2 1.8-V, 2.5-V, or 3.3-V to VDDIO on J17 and place corresponding strap selection shunts
– Place shunt at J24 to connect VDD1P1 LDO
– Remove shunt at J21 header
–
Wide Vin: Connect 5V - 36V to pin 1 of J18 and ground to pin 2 of J18
• DP83561EVM Onboard Power Using Power Jack
Board Setup Details
SLVUC11 – APRIL 2021
DP83561EVM User’s Guide
11
Copyright © 2021 Texas Instruments Incorporated