2
dc1941cfa
DEMO MANUAL DC1941C
connections
Jumpers
Each DC1941 contains an LTC6820, pulse transformer and
support electronics to evaluate isoSPI. To communicate
over the isoSPI bus, each SPI device requires one DC1941.
Since the LTC6804 devices already have built-in isoSPI,
a DC1941 is not required to connect to an LTC6804 (or
LTC6804 demo board). The 2-wire interface is accessible
using standard RJ45 connectors (J1 on the DC1941). This
allows for isoSPI interconnection using simple CAT5 cable
1
.
When the DC1941 is used to connect to an LTC6804, a
special interface is available to connect to a PC, and an
LTC6804 graphical user interface (GUI) is available to
display this information. The connection between the
DC1941 and the PC is made using Linear Technology’s
DC590B (USB serial controller). The DC590B is connected
to the DC1941 through J2 (DC590B connector, a 14-pin
ribbon connector). The DC590B can be used to power
the DC1941, or power can be provided externally (see
jumper settings).
There are several options for connecting SPI devices to
the DC1941. The J2 connector and JP1 (SPI connector,
a 6-pin header) both provide access to the SPI connec-
tions. Power can be supplied via J2, JP1 or the turrets
on the board.
Jumper settings are provided on the DC1941 to configure
the SPI mode, speed and master/slave operation. Jump-
ers are also provided to configure the isoSPI shutdown
and output power level, as well as power supply options.
Note 1:
A single twisted pair inside the CAT5 is used for the isoSPI
interconnection.
