Texas Instruments DAC5571, Руководство пользователя

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EVM Basic Functions
1-4
1.2.2 Reference Voltage
The 5-V precision voltage reference is provided to supply the external voltage
reference for the DAC8571 only through REF02, U3, via jumper TP9 by
shorting pins 1 and 2. The reference voltage goes through an adjustable 5-k
Ω
potentiometer R11 in series with 0-
Ω
R10, to allow the user to adjust the
reference voltage.
Caution
To avoid potential damage to the EVM board, make sure that the
correct cables are connected to their respective terminals as
labeled on the EVM board.
Stresses above the maximum listed voltage ratings may cause
permanent damage to the device.
Header J4 pin 20 provides a connection point for an alternative external
reference source if desired. In this configuration the jumper on TP9 must be
removed and TP8 must be shorted. The external voltage reference must not
exceed 5 V.
The REF02 circuit also provides an alternative adjustable analog supply for
U1, U4, and U8 (whichever is installed on the EVM) through W1 pin 1 if desired.
It also provides both reference and supply voltages for U4 by shorting TP9.
Since it is possible to install all DAC devices (U1, U4 and U8) on the EVM, the
possibility of different supply requirements may arise. To isolate the supply and
reference voltages of U4 from U1 and U8, remove R25 and install R38. This
allows the DAC8571 (U4) to operate using the REF02 (U3) as its supply and
reference sources while U1 and U8 are supplied by 5 VA.
The REF02 precision reference is powered by V
CC
(+15V) through J1 - 3 or
J6 - 1.