ltc2978 Linear Technology Corporation, ltc2978 Datasheet - Page 60

• Manufacturer Part Number: ltc2978
• Description: Octal Pmbus Power Supply Monitor And Controller With Eeprom
• Manufacturer: Linear Technology Corporation

applicaTions inForMaTion
LTC2978
Dongle Connections
Figure 20 illustrates the application schematic for powering
and programming one or more LTC2978’s from the LTC
PMBus controller in the absence of system power. Because
of the controller’s limited current sourcing capability, only
0
Figure 20. LTC Controller Connections for Powering and Communicating with the LTC2978
CONTROLLER
SYSTEM
HEADER
3.3V
LTC
NOTE: LTC CONTROLLER I
ISOLATED 3.3V FROM CONTROLLER CAN BE BACK DRIVEN AND WILL ONLY DRAW < 10µA
ISOLATED 3.3V CURRENT LIMIT = 100mA
ISOLATED 3.3V
SDA
SCL
V
GND
CTL
IN
LTC4412
SENSE
GATE
STAT
TP0101K-SSOT23
2
C CONNECTONS ARE OPTO-ISOLATED
TO/FROM OTHER
OR’d 3.3V
DIODE
IDEAL
LTC2978s
the LTC2978’s and the I
ered from the ORed 3.3V supply. In addition, any device
sharing I
have body diodes between the SDA/SCL pins and its V
node because this will interfere with bus communication
in the absence of system power.
0.1µF
0.1µF
2
C bus connections with the LTC2978 should not
V
V
V
V
SDA
SCL
SHARE_CLK
PWR
DD33
DD33
DD25
PIN CONNECTIONS
WP
OMITTED FOR
CLARITY
LTC2978
GND
2
C pull-up resistors should be pow-
2978 F10
2978fa
DD