lt1070hv Linear Technology Corporation, lt1070hv Datasheet - Page 3

• Manufacturer Part Number: lt1070hv
• Description: 5a And 2.5a High Efficiency Switching Regulators
• Manufacturer: Linear Technology Corporation

ELECTRICAL CHARACTERISTICS
range, otherwise specifications are at T
SYMBOL
V
B
V
I
f
DC (Max)
Note 1: Absolute Maximum Ratings are those values beyond which the life of
a device may be impaired.
Note 2: Minimum switch “on” time for the LT1070/LT1071 in current limit is
in the buck and inverting modes only , to 35V. Normal (unshorted) conditions
are not affected. Mask changes are being implemented which will reduce
minimum “on” time to 1 s, increasing maximum short-circuit input voltage
above 40V. If the present LT1070/LT1071 (contact factory for package date
code) is being operated in the buck or inverting mode at high input voltages
and short-circuit conditions are expected, a resistor must be placed in series
with the inductor, as follows:
The value of the resistor is given by:
LIM
FB
V
SAT
1 s. This limits the maximum input voltage during short-circuit conditions,
I
I
SW
IN
R =
t • f • V
I
LIMIT
IN
– V
PARAMETER
Flyback Reference Voltage
Change in Flyback Reference Voltage
Flyback Reference Voltage Line Regulation
Flyback Amplifier Transconductance (g
Flyback Amplifier Source and Sink Current
Output Switch Breakdown Voltage
Output Switch “On” Resistance (Note 4)
Control Voltage to Switch Current
Transconductance
Switch Current Limit (LT1070)
Switch Current Limit (LT1071)
Supply Current Increase During
Switch “On” Time
Switching Frequency
Maximum Switch Duty Cycle
Flyback Sense Delay Time
Shutdown Mode Supply Current
Shutdown Mode Threshold Voltage
F
– R
L
A
= 25 C. V
m
)
IN
= 15V, V
CONDITIONS
I
0.05 I
I
V
V
3V V
LT1070
LT1071
LT1070
LT1071
Duty Cycle 50%, T
Duty Cycle 50%, T
Duty Cycle = 80% (Note 5)
Duty Cycle 50%, T
Duty Cycle 50%, T
Duty Cycle = 80% (Note 5)
3V V
3V V
FB
FB
C
C
The denotes the specifications which apply over the full operating temperature
I
(LT1070/LT1071)
(LT1070HV/LT1071HV)
C
= 0.6V, I
= 0.6V, I
= 50 A
= 50 A, 3V V
= 10 A
C
IN
IN
IN
FB
= 0.5V, V
V
V
V
FB
FB
1mA
MAX
MAX
MAX
= 50 A (Source)
= 50 A (Sink)
t = Minimum “on” time of LT1070/LT1071 in current limit, 1 s
f = Operating frequency (40kHz)
V
I
R
Note 3: V
breakdown.
Note 4: Measured with V
and 2A for LT1071.
Note 5: For duty cycles (DC) between 50% and 80%, minimum
guaranteed switch current is given by I
LT1070 and I
, I
, V
LIMIT
F
L
SW
IN
= Forward voltage of external catch diode at I
FB
C
= Internal series resistance of inductor
J
J
J
J
= 0.05V
= 1.5mA
< 25 C
< 25 C
= Current limit of LT1070 ( 8A), LT1071 ( 4A)
= V
V
25 C
25 C
MAX
MAX
REF
(Note 3)
LIM
, output pin open unless otherwise specified.
= 55V for LT1070HV and LT1071HV to avoid switch
= 1.67 (2 – DC) for the LT1071.
C
in hi clamp, V
MIN
150
100
4.5
2.5
2.5
2.0
15
14
15
25
65
75
35
33
90
50
5
5
4
LIM
LT1070/LT1071
FB
= 3.33 (2 – DC) for the
= 0.8V. I
16.3
0.01
0.15
0.30
TYP
300
100
150
6.8
1.5
32
40
90
90
25
40
92
8
4
LIMIT
SW
= 4A for LT1070
MAX
17.6
18.0
0.03
0.24
0.50
650
250
250
300
8.5
5.0
5.5
5.0
70
70
10
11
10
35
45
47
97
UNITS
10701fe
mA/A
3
mho
%/V
kHz
kHz
A/V
A/V
mV
mV
%
V
V
V
A
A
V
V
A
A
A
A
A
A
A
s