LT8471
4
8471fd
For more information www.linear.com/8471
PARAMETER CONDITIONS MIN TYP MAX UNITS
Switch Current Limit (Primary Channels) Minimum Duty Cycle (Note 3)
Maximum Duty Cycle (Notes 3, 4)
l
l
2.1
1.35
2.55
1.8
3.2
2.5
A
A
Switch Current Limit (Skyhook) (Note 3)
l
400 500 600 mA
Primary Switches V
CESAT
I
C1
or I
C2
= 1.5A 300 mV
Skyhook Switch V
CESAT
I
C3
= 250mA 250 mV
C1, C2 Leakage Current V
C1
= V
C2
= 12V, V
E1
= V
E2
= 0V, V
OV/UV
= 0V,
Current into Pin
0.01 1 μA
C3 Leakage Current V
C3
= 12V, V
OV/UV
= 0V 0.01 1 μA
E1, E2 Leakage Current V
OV/UV
= 0V, Current Out of Pin
V
C1
= V
C2
= 20V, V
E1
= V
E2
= 5V
V
C1
= V
C2
= 5V, V
E1
= V
E2
= –10V
0.01
0.01
1
1
µA
µA
Schottky Reverse Leakage V
REVERSE
= 12V
V
REVERSE
= 50V
0.01
0.02
1
2
µA
µA
Schottky Forward Voltage I
DIODE
= 100mA 650 mV
Start-Up Characteristics
Soft-Start Charge Current V
SS1
, V
SS2
= 50mV, Current Flows Out of
SS1, SS2 Pins
l
5.5 8.5 11.5 µA
OV/UV Current for OVLO Current into OV/UV Pin. V
OV/UV
Internally Clamped
to 1.37V, Current Rising
l
76 80 84 µA
OV/UV Pin Bias Current V
OV/UV
=1V 0.01 0.5 µA
OV/UV Minimum Input Voltage High Active Mode, OV/UV Rising
Active Mode, OV/UV Falling
l
l
1.165
1.13
1.215
1.18
1.265
1.22
V
V
OV/UV Input Voltage Low Shutdown Mode
l
0.3 V
FB Pin Threshold for Power Good
(Positive Output Voltage)
FB Rising
FB Falling
l
l
715
708
740
730
765
752
mV
mV
FB Pin Threshold for Power Good
(Negative Output Voltage)
FB Falling
FB Rising
l
l
–766
–755
–736
–727
–706
–699
mV
mV
PG1, PG2 Voltage Output Low V
FB
= 0.6V, I
PG
= 250μA 0.32 0.6 V
PG1, PG2 Leakage V
PG1
, V
PG2
= 12V, PG Driver Off 0.01 1 µA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LT8471E is guaranteed to meet performance specifications from
0°C to 125°C junction temperature. Specifications over the –40°C to 125°C
operating junction temperature range are assured by design, characterization
and correlation with statistical process controls. The LT8471I is guaranteed
over the full –40°C to 125°C. The LT8471H is guaranteed over the full –40°C
to 150°C operating junction temperature range. Operating lifetime is derated
at junction temperatures greater than 125°C.
elecTrical characTerisTics
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN1
= V
IN2
= 5V, unless otherwise noted (Note 2).
Note 3: Current limit guaranteed by design and/or correlation to static test.
Note 4: Current Limit measured at equivalent switching frequency of 1MHz.
Note 5: This IC includes overtemperature protection that is intended
to protect the device during momentary overload conditions. Junction
temperature will exceed 150°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
temperature may impair device reliability.
Note 6: Low side and high side configurations are discussed in the Switch
Configurations and the Skyhook Regulator section.
Note 7: Minimum switch on-time, off-time is guaranteed by design.
