4
dc1880af
DEMO MANUAL DC1880A
aDDitional information
VL Logic Supply
Table 1 lists several ways to supply power to the VL pin.
Methods 1a/b/c are recommended for most purposes.
Table 1. Recommended Options for Powering the VL Supply
METHOD
DC590
JP6
DC1880A
JP12
DC1880A
JP11
SOURCE FOR
VL POWER
1a
1b
1c
5V*
3.3V
OPEN
(2.7V)
ON*
ON*
ON*
5V*
3.3V
OPEN (2.9V)
LDO or DC590
LDO or DC590
LDO or DC590
2 EXT ON* X** LDO
3 EXT OPEN X** DC1880A VL TURRET
4 5V* or 3.3V OPEN X** DC590
* (Default)
** Including OPEN (2.9V)
L+ Power Supply Outputs
Enable the L+ power supply outputs by setting their
respective EN_L+ register bits high.
CQ Line Driver Outputs
Enable the CQ line drivers either by input pin (using the
TXEN turrets and/or jumpers JP1/3/7/9) or via the SPI
interface (by setting DRVEN register bits high). See Table 2.
Table 2. CQ Driver Mode Configuration
JP1/3/7/9
SETTING
TXEN
TURRET
DRVEN
BIT
CQ DRIVER
MODE
GND
VL
X
EXT
X
X
X
L/H
0
X
1
0
OFF
ON
ON
OFF/ON
Control the output CQ states using the TXD turrets and/
or jumpers JP2/4/8/10. See Table 3.
Table 3. CQ Driver Output Level Configuration
JP2/4/8/10
SETTING
TXD
TURRET
DRVEN
BIT
CQ DRIVER
MODE*
CQ
LEVEL
GND
GND/VL
EXT
DB9
X
X
L/H
X
X
X
X
H/L**
OFF
ON
ON
ON
L
H/L
H/L
H/L
* From T
able 2
** RS232 transceiver U2 inverts
Alternatively, operate the CQ drivers solely via the SPI
interface by tying TXD low and controlling the DRVEN
register bits. This method is suitable for SIO mode and
switching at or below COM2 data rates (38.4kb/s).
TVS Protection
The CQ and L+ pins are protected by 36V TVS diodes for
cable-driving applications.
Serial Port
A DB9 connector enables CQ data to be sent (for one or
more ports) and received (for one port) using PC software
such as a serial terminal program. Jumper JP5 enables
the required RS-232 transceiver.
Select the desired combination of drivers by setting one
or more of JP2/4/8/10 to the DB9 position. Select one CQ
receiver using JP6.
L+ Isolation
If L+ isolation is not needed, Schottky diodes D1-D4 may
be replaced with 0Ω resistors.
Interrupts
The LTC2874 includes an open-drain interrupt line for
signaling the host controller when it needs service. This
signal is accessible on the
DC1880A board at the IRQ
test
point. An LED is also included for convenience.
5
dc1880af
DEMO MANUAL DC1880A
aDDitional information
Jumpers
JP1/3/7/9: Port 4/3/2/1 CQ Driver Enables. See Table 2.
Default position VL.
JP2/4/8/10: Port 4/3/2/1 Data Input to CQ Driver. See
Table 3. Default position GND.
JP6: RXDn COM Port Select. Determines which receiver
output (RXD1/2/3/4, if any) is connected to the serial port.
Default position RXD1.
JP5: COM PORT Enable. Connects RS232 transceiver U2
to VL logic supply. Default position ON.
JP11: VL Select. Programs LDO voltage to 2.9V (OPEN),
3.3V, 5V, or 5.5V. Default position 5V.
JP12: LDO On. Enables LDO which derives VL logic sup
-
ply from V
DD
supply voltage input. Default position ON.
JP13: GND Shield. Shorts shields of J5-8 to GND. Default
position OPEN.
6
dc1880af
DEMO MANUAL DC1880A
using the Dc1880a software
Introduction
Linear Technology’s QuikEval software provides a quick
and easy way to evaluate most aspects of LTC2874 opera
-
tion. It operates a SPI interface that reads or writes from
the 14 onboard registers via a DC590 serial controller.
Install QuikEval BEFORE connecting the DC1880A to the
USB port of the PC. Download and run the installation
program from http://www.linear.com/software and follow
the onscreen instructions. The LTC2874 GUI will launch
automatically when the PC begins communicating with
the DC1880A via the serial controller. Thereafter, start
the GUI by running QuikEval from:
C:\Program Files\LTC\QuikEval\quikeval.exe
If the QuikEval software was installed previously, update
it to the latest version using Tools > Update Program.
The LTC2874 GUI is composed of a main window having
three tabs, and a Register Map window. The Ports tab
(Figure 2) contains controls and monitors that are unique to
each individual port. The Timers and Globals tab (Figure 3)
contains controls
and monitors that are common to all
ports. The Events tab (Figure 4) provides access to event
monitoring registers. The Register Map window (Figure 5)
provides access to all register bits via an alternate format.
The LTC2874 GUI
begins communicating with the DC1880A
automatically. Once running, it continuously polls the
LTC2874 registers to monitor status.
Connect/Disconnect Button
The Disconnect button disables the SPI interface and most
of the GUI. The Connect button restarts SPI polling and
activates the complete GUI.
Reset Button
This button issues a SPI Reset command, returning all
registers to default values.
Events Tab
This tab contains lamps that map to Event Register bits.
A lamp that is on indicates that the corresponding bit in
the LTC2874 Event Register has been set. Clicking on a
lamp will clear the Event bit if the condition no longer
persists. Event Register behavior is sticky, meaning each
lamp stays on until cleared.
The check boxes control which events will cause IRQ to
signal.
Register Map
This window presents all register bits in an alternate format.
Change register values directly by clicking on individual
bits, using arrow widgets, or by entering numeric values.
Changed bits appear yellow until either committed to the
LTC2874 by pressing the Write and Update button, or
cleared by pressing the Discard Unwritten Changes button.
The Save Current Values button saves the LTC2874 register
values to a text file. The
Load Saved Values button loads
the register values from one such file into the Register Map
window. (Write and Update will then configure LTC2874
accordingly.)
Running QuikEval GUI Using Linduino One
The QuikEval GUI software for DC1880A may be operated
using a Linduino One (DC2026) with the DC590 emulator
sketch in place of the DC590. When using this USB-isolated
Arduino-compatible demonstration board, set the DC1880A
LDO to 5V (JP11=5.0V) or disable it (JP12=OPEN).

DC1880A

Mfr. #:
Manufacturer:
Analog Devices Inc.
Description:
Power Management IC Development Tools LTC2874 Demo Board - Quad IO-Link Master
Lifecycle:
New from this manufacturer.
Delivery:
DHL FedEx Ups TNT EMS
Payment:
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