LT1940 Linear Technology, LT1940 Datasheet - Page 2

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

ABSOLUTE AXI U RATI GS
LT1940
(Note 1)
V
BOOST Pin Voltage .................................................. 35V
BOOST Pin Above SW Pin ....................................... 25V
PG Pin Voltage ......................................................... 25V
SHDN, FB Pins ........................................................... 6V
SW Voltage ................................................................V
Maximum Junction Temperature .......................... 125 C
Operating Temperature Range (Note 2) ...–40 C to 85 C
Storage Temperature Range ..................–65 C to 150 C
Lead Temperature (Soldering, 10 sec).................. 300 C
temperature range, otherwise specifications are at T
PARAMETER
Minimum Operating Voltage
Quiescent Current
Shutdown Current
Feedback Voltage
FB Pin Bias Current
Reference Line Regulation
Error Amp GM
Error Amp Voltage Gain
V
V
V
V
V
Switching Frequency
Switching Phase
Maximum Duty Cycle
Frequency Shift Threshold on FB
Foldback Frequency
Switch Current Limit
Switch V
Switch Leakage Current
2
ELECTRICAL CHARACTERISTICS
C
C
C
C
C
IN
Sink Current
Pin to Switch Current Gain
Clamp Voltage
Source Current
Switching Threshold
Voltage .................................................. (–0.3), 25V
CESAT
W
W W
U
A
= 25 C. V
CONDITIONS
Not Switching
V
0 C to 70 C
–40 C to 85 C
V
V
V
V
f
V
Note 3
I
SW
SW
RUNSS
IN
FB
FB
FB
FB
The
5V to 25V
= 1V
= 1.5V
= 1.1V
= 1MHz
= 0V
= 1A
= 0V
IN
IN
denotes the specifications which apply over the full operating
= 5V, V
PACKAGE/ORDER I FOR ATIO
Consult LTC Marketing for parts specified with wider operating temperature ranges.
BOOST1
BOOST2
BOOST
SW1
SW2
V
V
V
V
IN
IN
IN
IN
UNDERSIDE METAL MUST BE
T
16-LEAD PLASTIC TSSOP
= 8V unless otherwise noted. (Note 2)
JMAX
1
2
3
4
5
6
7
8
SOLDERED TO GROUND
= 125 C,
FE PACKAGE
TOP VIEW
JA
= 45 C/W
16
15
14
13
12
11
10
9
FB1
V
PG1
RUN/SS1
RUN/SS2
PG2
V
FB2
C1
C2
1.230
1.225
1.215
0.95
MIN
150
1.8
78
1
U
1.250
1.250
1.250
0.005
0.75
TYP
240
330
180
180
150
210
3.4
3.8
2.4
1.8
1.1
1.1
0.5
2.4
30
42
60
88
ORDER PART
LT1940EFE
NUMBER
W
1.270
1.270
1.270
1200
MAX
1.25
1.35
210
320
3.6
4.8
3.2
45
10
uMhos
UNITS
U
MHz
MHz
%/V
1940i
Deg
kHz
A/V
mA
mV
nA
%
V
V
V
A
V
A
A
A
V
V
V
A