Texas Instruments ADS1254, Руководство пользователя

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Connectors
3-6
3.3.3 J1, J4, J5, BT1: Power Connectors
The ADS1254EVM features a flexible power supply. Externally generated
power, the onboard regulator circuitry and an ac adaptor, or a 9-V battery may
all be used to supply power. Furthermore, the separated analog and digital
power supplies may be powered differently; for example, the analog power
supply may be powered externally, and the digital power supply may use the
built-in regulator, at the same time. (This is configured using jumpers JMP2
and JMP3.) The exception to this is that the battery and ac adaptor cannot be
used at the same time (see below).
An additional source of power may come from a DSP development board
(DSK). When the ADS1254EVM is plugged in to a DSK motherboard, the
onboard regulators are shut down, and power is sourced from the DSK. The
DSK’s power supply, however, may not be suitable for powering the analog
circuitry, as it is likely to be somewhat dirty, so for best performance it is
necessary to use an external supply for the analog circuitry when using the
ADS1254EVM with a DSK.
Four power connectors are provided: screw terminal blocks J4 and J5 for
external power, battery terminal BT1 for a 9-V transistor radio battery, and J1
for a wall-wart. J1 is a switched jack: connecting a plug to J1 automatically
disconnects the battery terminal. This prevents the battery and J1 from
supplying power simultaneously.
Battery power is regulated by the same circuitry that regulates J1 (wall-wart)
power.
Be very careful when connecting external power supplies to J4 and J5.
They are not protected against reversed polarity. If you connect them
backwards (that is, with reversed polarity), permanent damage to the
ADS1254EVM is likely.
Table 3−4. J1: Unregulated Power Input Connector
Terminal Name Function
Tip Positive power supply input
Sleeve Power ground
Table 3−5. J4: External Digital Power Supply Input Connector
Terminal Number Function
1 Digital positive power supply input
2 Digital ground
Table 3−6. J5: External Analog Power Supply Input Connector
Terminal Number Function
1 Analog positive power supply input
2 Analog ground