Datasheet

LTC2978A
76
2978afa
For more information www.linear.com/LTC2978A
APPLICATIONS INFORMATION
Connecting the DC1613 USB to I
2
C/SMBus/PMBus
Controller to the LTC2978A in System
The DC1613 USB to I
2
C/SMBus/PMBus Controller can be
interfaced to LTC2978As on the user’s board for program-
ming, telemetr
y
and system debug. The controller, when
used in conjunction with LTpowerPlay software, provides
a powerful way to debug an entire power system. Failures
are quickly diagnosed using telemetry, fault status registers
and the fault log. The final configuration can be quickly
developed and stored to the LTC2978A’s EEPROM.
Figure 30. DC1613 Controller Connections When V
PWR
is Used
V
PWR
V
DD33
V
DD33
V
DD25
SCL
SDA
SHARE_CLK
LTC2978A
PIN CONNECTIONS
OMITTED FOR
CLARITY
0.1µF
4.5V TO 15V
0.1µF
0.1µF
WP GND
2978a F30
5.49k10k
49.9k
Si1303
TO DC1613
I
2
C/SMBUS/PMBUS
CONTROLLER
TO/FROM OTHER
LTC2978As
150k
REPEAT OUTLINED CIRCUIT FOR EVERY LTC2978A
10k
ISOLATED 3.3V
SCL
SDA
GND
Figures 30 and 31 illustrate application schematics for
powering, programming and communicating with one
or more LTC2978A’s via the DC1613 I
2
C/SMBus/PMBus
controller regardless of whether or not system power is
present.
Figure 30 shows the recommended schematic to use when
the LTC2978A is powered by the system intermediate bus
through its V
PWR
pin.