Demonstration Circuit 1680B Operation - Analog Devices DC1840C Demo Manual

DEMONSTRATION CIRCUIT 1680B OPERATION

Demonstration circuit 1680B is a 12-Port, IEEE802.3at
Type 1 and Type 2 PoE PSE mother board. This board ac-
cepts various PSE daughter cards featuring Analog Devices
PSE controllers. The DC1680B is capable of powering up
to 12 PDs.
Daughter Card Insertion Precautions
When inserting or removing the daughter card into the
DC1680B, verify all supplies and LEDs are off. Push the
card straight down for insertion or pull straight up for
removal to avoid bending the connector pins. Follow the
instructions in the Quick Start Procedure for alignment.
V Supply
EE
Connect a power supply for V
and negative rail to NEG as shown in Figure 3 of the Quick
Start Procedure. Set the voltage within the range in Table 1
depending on whether the application is a Type 1 or Type 2.
Choose a power supply rating and set the current limit
high enough to provide power for the maximum number of
PDs connected and to meet each PD power requirements.
Table 1. DC1840C V Power Range for Type 1 and Type 2 PSEs
EE
V SUPPLY
EE
PSE TYPE RANGE
Type 1 45V to 57V
Type 2 51V to 57V
*Recommended DC1840C power supply minimum to avoid drooping in
a worst-case scenario with I current at all 12 ports.
LIM
PD Connection
PDs are connected using an Ethernet cable to any of the
12 ports at the 2×6, RJ45 connector J4 on the DC1680B
(Figure 3). Test points for port outputs OUT1 through
OUT12 are provided.
with the positive rail to POS
EE
MAX DELIVERED POWER
PORT POWER SUPPLY*
13W 300W
25.5W 600W
DEMO MANUAL DC1840C
DC1680B USER FEATURES
Refer to Figure 12 and Figure 13 for the following user
features.
Onboard 3.3V Supply
The DC1680B has an onboard V
erated from the V supply. V
EE
DGND is a negative voltage referenced to AGND. If an
external 3.3V supply is to be used, contact Analog Devices
Applications for proper connection.
V and V LED Indicators
EE DD33
LEDs for V and V
EE DD33
these supplies. Verify these LEDs are off before inserting
or removing the daughter card.
Digital Connections
The DC1680B has connections for I
host controller. The DC590 is optionally connected to
the DC1680B at J5 through a 14-pin ribbon cable. The
QuikEval software will automatically detect the DC1680B
and open the LTC4271 GUI. A second 14-pin ribbon cable
can be connected to J6 for I
DC1680B board with slight board modifications. Contact
Analog Devices Applications for instructions.
Digital test points include SCL, SDA, DGND, INT, MSD,
2
and RESET. I C address pin AD6, AD3, and AD2 are set
with a 3-bit switch SW3.
Midspan PSE
The DC1840C can be configured as a midspan PSE.
Upstream switch data comes in to J3. Data and PoE go
out to a PD at J4. Set both MID and AUTO pins logic high.
digital supply gen-
DD33
is tied to AGND, and
DD33
indicate if voltage is present at
2
C control from a
2
C expansion to another
Rev E
9