LTC1559 View Datasheet(PDF) - Linear Technology
Part Name
Description
MFG CO.
'LTC1559' PDF : 12 Pages View PDF
LTC4416/LTC4416-1
U
OPERATIO
V1 is Greater Than V2 Operation
When VE1 is below the VREF threshold, channel 1 is in
a “soft-off mode”. This means that G1 will only provide
an IG(SRC) current instead of an IG(SNK) or an IGFON(SNK)
current.
When VE1 is above the VREF threshold, channel 1 is im-
mediately fully enabled, and G1 will become active imple-
menting the output current listed in Figure 1.
Channel 2 is fully enabled. If VV1 – VVS < VRTO, channel 2
will implement all of the IG2 currents listed in Figure 1.
Channel 1 is Disabled
The LTC4416 is not designed to have channel 1 disabled
by grounding E1 and leaving E2 in an indeterminate state.
If this happens, the channel 2 PowerPath controller will
not have reverse turn-off capability. No electrical harm to
the LTC4416 will occur.
Channel 2 is Disabled
The LTC4416 is not designed to have channel 2 disabled
by connecting E2 high and leaving E1 in an indeterminate
state. If this happens, the channel 1 PowerPath controller
will not have reverse turn-off capability. No electrical harm
to the LTC4416 will occur.
Both Channels Disabled
When both channels of the LTC4416 are disabled, both
G1 and G2 currents are set to IG(SRC).
LTC4416-1 Operation
The LTC4416-1 is designed for overvoltage/undervoltage
protection or when either voltage path must be turned off
rapidly, regardless of the status of the other voltage input.
The LTC4416-1 does not implement the soft-off feature
implemented in the LTC4416. The E1 and E2 inactive will
force the IG current of their respective channel to IG(OFF).
Table 2 explains the operation of the E1 and E2 inputs.
The term “active” implies that IG(OFF) current is forced on
the Gn pins regardless of the VVn – VVS value. The term
“enabled” implies that IG(OFF) current is provide on the Gn
pins if and only if VVn – VVS < VRTO.
Table.2 LTC4416-1 Operational Modes
E1 E2 Operation Mode
0 X Undervoltage Protection
X 1 Overvoltage Protection
1 X Channel 1 PowerPath
X 0 Channel 2 PowerPath
IG(OFF)1
Active
Enabled
IG(OFF)2
Active
Enabled
APPLICATIO S I FOR ATIO
LTC4416
The LTC4416 is designed to support three major ap-
plications. The first two applications assume that V1 is
the primary power source and V2 is the backup power
source. The first application is where the V1 power supply
is normally less than V2. The second application is where
the V1 power supply is normally greater than V2. The third
application addresses the load sharing case where both
V1 and V2 are relatively equal in value.
V1 is Less Than V2
Figure 2 illustrates the external resistor configuration for
this case.
V1 = 9V (FAIL)
V1 = 10.8V (RESTORE)
V1
R2A
158k
R2E R2C
105k 24.9k
GND
V2
V2 = 14.4V
PRIMARY SUPPLY
Q1
SUP75P03_07
LTC4416
E1
V1
H1
G1
GND
VS
VS
E2
G2
H2
V2
BACKUP SUPPLY
Figure 2
Q2 Q3
SUP75P03_07
4416 F02
4416fa
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