LT1940 Linear Technology, LT1940 Datasheet - Page 3

• Manufacturer Part Number: LT1940
• Description: Dual Monolithic 1.4A/ 1.1MHz Step-Down Switching Regulator
• Manufacturer: Linear Technology

temperature range, otherwise specifications are at T
PARAMETER
Minimum Boost Voltage
Boost Pin Current
RUN/SS Current
RUN/SS Threshold
PG Threshold Offset
PG Voltage Output Low
PG Pin Leakage
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LT1940E is guaranteed to meet performance specifications
from 0 C to 70 C. Specifications over the –40 C to 85 C operating
ELECTRICAL CHARACTERISTICS
TYPICAL PERFOR A CE CHARACTERISTICS
1.2
1.0
1.8
1.6
1.4
90
80
70
60
50
0
0
Efficiency, V
Maximum Load Current,
V
V
L = 2.2 H (SUMIDA CR43-2R2)
OUT
OUT
2
= 1.8V
= 1.8V
4
LOAD CURRENT (A)
INPUT VOLTAGE (V)
0.5
L = 1 H
6
OUT
V
IN
L = 1.5 H
= 1.8V
= 5V
8
10
1.0
L = 2.2 H
12
W
14
1940 G01
1940 G04
U
1.5
16
100
1.8
1.6
1.4
1.2
1.0
90
80
70
60
50
A
Efficiency, V
0
0
Maximum Load Current,
V
V
L = 3.3 H (SUMIDA CR43-3R3)
OUT
= 25 C. V
OUT
CONDITIONS
I
I
V
V
V
V
SW
SW
FB
FB
PG
IN
= 3.3V
= 3.3V
The
= 18V
= 1.25V, I
5
= 1A
= 1A
Rising
= 2V
LOAD CURRENT (A)
INPUT VOLTAGE (V)
0.5
L = 2.2 H
IN
L = 4.7 H
OUT
denotes the specifications which apply over the full operating
10
= 5V, V
V
PG
IN
= 3.3V
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: Current limit is guaranteed by design and/or correlation to static
test. Slope compensation reduces current limit at high duty cycle.
L = 3.3 H
= 12V
= 250 A
15
BOOST
1.0
20
= 8V unless otherwise noted. (Note 2)
V
IN
= 5V
1940 G02
1940 G05
1.5
25
100
400
200
100
300
90
80
70
60
0
Efficiency, V
0
0
Switch V
V
L = 4.7 H (SUMIDA CR43-4R7)
OUT
MIN
0.3
V
90
IN
= 5V
= 18V
0.5
CESAT
LOAD CURRENT (A)
0.5
SW CURRENT (A)
TYP
0.22
125
OUT
1.8
2.3
0.6
0.1
20
V
IN
1.0
= 5V
= 12V
LT1940
MAX
160
2.5
0.4
1.0
30
1
1.5
V
IN
UNITS
= 8V
1940 G03
1940 G06
3
1940i
mA
mV
1.5
2.0
V
A
V
V
A
B