Linear Technology DC1962C, Демонстрационное руководство

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dc1962cf
DEMO MANUAL DC1962C
aDvanceD Demo BoarD operations
Fault Sharing Setup in the GUI
Fault sharing provides a means of propagating a fault
detected by a power manager to other power managers via
FAULT pins. Use the Fault Sharing Setup Tool to configure
the fault sharing in the GUI. Select the LTC2974 in the
system tree. Go to Utilities > Fault Sharing Diagram. For
more details on this topic, please refer to the MFR_FAULTB
propagate and response sections in the data sheet.
channels on the DC1962C demo board since the fault pins
are tied together.
NOTE: All FAULT pins on all power managers are tied to-
gether on the DC1962C demo board. These pins are open
drain and have a common pull-up resistor to provide a
logic high level (inactive). All FAULT pins are active low.
There are two types of actions to fault conditions: How a
channel responds to another channel’s fault and whether
a particular channel propagates its fault to other channels.
FAULT pins are bi-directional, meaning the device may
drive its fault pin low (output) or may respond to the fault
pin when another device drives it low (input). Because all
fault pins are wire OR’d on the DC1962C, this hardware
configuration allows one to program each device’s fault
settings on a channel-by-channel basis. By default, the
LTC2974 is configured to shut down its channels if
other devices fault and to propagate its own fault via the
FAULT pins. The LTC2977 is configured the same as the
LTC2974, however zone 1 (U2:4-U2:7) is configured to not
propagate a fault. A fault on these channels will cause only
that channel to fault off. You can think of the “Response”
switches as “shut this channel down when another channel
faults”, and the “Propagate” switches as “drive a fault pin
to broadcast to other channels that this channel faulted.”
Figure 8. Fault Sharing Utility in LTpowerPlay GUI
The LTC2974 fault sharing dialog will appear as shown in
Figure 8. All Response and all Propagate switches are closed
by default. In this configuration, a fault on an LTC3880 or
LTC2977 channel will shut down all LTC2974 channels,
and a fault on any LTC2974 channel will propagate to all