LTC4300A-3
10
4300a3fa
5V to 3.3V Level Translator and Power Supply
Redundancy
Systems requiring different supply voltages for the back-
plane side and the card side can use the LTC4300A-3, as
shown in Figure 5. The pull-up resistors on the card side
connect from SDAOUT to SCLOUT to V
CC2
, and those on
the backplane side connect from SDAIN and SCLIN to V
CC
.
The LTC4300A-3 functions for voltages ranging from 2.7V
to 5.5V on both V
CC
and V
CC2
. There is no constraint on
the voltage magnitudes of V
CC
and V
CC2
with respect to
each other.
This application also provides power supply redundancy.
If the V
CC2
voltage falls below its UVLO threshold, the
LTC4300A-3 disconnects the backplane from the card,
so that the backplane can continue to function. If the
V
CC
voltage falls below its UVLO threshold and the V
CC2
voltage remains active, hold ENABLE at ground to ensure
proper operation.
applicaTions inForMaTion
Figure 4. The LTC4300A-3 in a Custom Application. Making ENABLE the Shortest Pin Ensures that
V
CC
and V
CC2
Connect Before ENABLE Is Allowed to Go High, Connecting the Card to the Backplane
V
CC
SDAIN
SCLIN
V
CC2
GND
SDAOUT
SCLOUT
ENABLE
4300A-3 F04
I/O PERIPHERAL CARD 1
LTC4300A-3
C2
0.01µF
CARD_SCL
CARD_SDA
R7
10k
R8
10k
V
CC2
BACKPLANE
BACKPLANE
CONNECTOR
SDA
SCL
ENA2
ENA1
V
CC
C1
0.01µF
V
CC
SDAIN
SCLIN
V
CC2
GND
SDAOUT
SCLOUT
ENABLE
I/O PERIPHERAL CARD 2
LTC4300A-3
C4
0.01µF
CARD2_SCL
CARD2_SDA
C3
0.01µF
STAGGERED CONNECTORSTAGGERED CONNECTOR
R1
10k
R2
10k
R3
10k
R4
10k
R5
10k
R6
10k
