PVDD/AVDD
GND
AVSS
GND
GND
DVDD
EVM Hardware Overview
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SBAU248 – November 2016
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DAC8775EVM User’s Guide
2.4
Powering the EVM
This section describes the various power configurations that can be used by the EVM.
2.4.1
PVDD_X/AVDD Supply
The PVDD_X, the buck-boost converter supplies, and AVDD, the analog supply, of the DAC8775 are
connected to the same power net labeled PVDD/AVDD on the DAC8775EVM. Terminal block J2, shown
in
Figure 3
, allows for external voltage sources to be connected to the PVDD/AVDD supply. The
PVDD/AVDD supply must be provided regardless of whether the buck-boost converter is in use or not.
Figure 3. PVDD/AVDD, AVSS, and DVDD Supply Connections
2.4.2
VPOS_X and VNEG_X Supplies
VPOS_X, the positive supply for the output signal chain, and VNEG_X, the negative supply for the output
signal chain, may be powered by the DAC8775 internal buck-boost converters or by off-board supply
voltages.
WARNING
Permanent device damage may occur if externally supplying
VPOS_X or VNEG_X while the internal buck-boost supply is
enabled.
When using the DAC8775 internal buck-boost converters to supply VPOS_X and VNEG_X, install JP1
through JP8 (or the two jumpers that correspond to the channel of interest) in the 1-2 position, or "inside"
position, as indicated by
Table 3
.
When using external equipment to supply VPOS_X and VNEG_X, install JP1 through JP8 (or the two
jumpers that correspond to the channel of interest) in the 2-3 position, or "outside" position, as indicated
by
Table 3
. In this configuration, the VPOS_X supplies are connected to the PVDD/AVDD net and the
VNEG_X supplies are connected to the AVSS net. If bipolar supplies are used, connect an appropriate
negative supply voltage to AVSS through terminal block J3, as shown in
Figure 3
. If unipolar supplies are
used, connect AVSS to ground through terminal block J3.