microDXP Technical Reference Manual
Version 3.15
October 7, 2019
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transfers, up to 2 Mbytes/sec. The SPORT option is targeted for multi-channel systems and
will require some user hardware and DSP code development.
The board-to-board connector supports RS-232 and SPORT serial communications, as well
as parallel IDMA access to DSP memory for transfer rates up to 10 Mbytes/sec. This
parallel IDMA interface is used as the basis for the MicroComU USB interface.
The latest microDXP hardware includes an optional on-board USB interface, simplifying
the implementation design process for embedded systems. With this option, the customer
need only provide power and auxiliary digital I/O connections via the flat-flex cable or
board-to-board connector.
1.3.2 Analog Input
The analog input signal enters via a separate connector to ensure immunity from electro-
magnetic interference. Twisted-pair, coaxial and board-to-board connections are
supported. See Appendix A for more information.
1.3.3 Power Supplies
Two power supply variants are available, corresponding to whether on-board regulators for
the analog supply voltages are used or are bypassed. If +/-5.0 V is supplied directly, either
linear regulated or high-quality switching supplies should be used. If the on-board LDO
regulators are used a minimum of +/-5.50 V is required, and the ripple requirement can be
relaxed a bit.
If planning to use the MicroComU companion board, choose the variant of the microDXP
that includes on-board voltage regulators. Aside from this, the MicroComU board will take
care of generating all required voltages for the microDXP, at the specified currents and
noise performance.
Regulated Supply Option: (<20mV pk-pk noise)
Voltage Range
Current (min)
Current (max)
Description
+3.3V
+/- 150mV
150mA
200mA
Decent switching supply
+5.0V
+/- 100mV
25mA
30mA
Linear or high-quality
switching
-5.0V
+/- 100mV
25mA
30mA
Linear or high-quality
switching
Unregulated Supply Option: (<100mV pk-pk noise)
Voltage Range
Current (min)
Current (max)
Description
+3.3V
+/- 150mV
150mA
200mA
Decent switching supply
+5.5V
to +6.0V
25mA
35mA
Decent switching supply
-5.5V
to –6.0V
25mA
35mA
Decent switching supply
Table 1-2: Power supply options and specifications for the microDXP.
For both variants, the onboard digital circuitry draws from a 3.3V supply input. The ripple
requirements for this supply are not particularly stringent, though excessive radiated noise
is to be avoided. If a switching supply is used, it should be well shielded from, and properly
grounded with respect to, the microDXP.
