lt1940l Linear Technology Corporation, lt1940l Datasheet - Page 2

• Manufacturer Part Number: lt1940l
• Description: Lt1940l - Dual Monolithic 1.4a, 1.1mhz Step-down Switching Regulator
• Manufacturer: Linear Technology Corporation

ABSOLUTE AXI U RATI GS
LT1940/LT1940L
(Note 1)
V
BOOST Pin Voltage
BOOST Pin Above SW Pin
PG Pin Voltage
SW Voltage ................................................................V
RUN/SS, FB Pins ...................................................... 6V
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
2
ELECTRICAL CHARACTERISTICS
C
C
C
C
C
IN
Sink Current
Pin to Switch Current Gain
Clamp Voltage
Source Current
Switching Threshold
LT1940 .................................................... (–0.3), 25V
LT1940L ................................................... (–0.3), 7V
LT1940 ................................................................ 35V
LT1940L ............................................................. 16V
LT1940 ................................................................ 25V
LT1940L ............................................................. 16V
LT1940 ................................................................ 25V
LT1940L ............................................................... 7V
Voltage
W
W W
U
A
= 25 C. V
CONDITIONS
Not Switching
V
0 C to 70 C
–40 C to 85 C
V
LT1940: V
LT1940L: V
V
V
V
f
SW
RUNSS
FB
FB
FB
FB
The
= 1.25V, V
= 1V
= 1.5V
= 1.1V
= 1MHz
= 0V
IN
IN
IN
denotes the specifications which apply over the full operating
IN
= 5V, V
5V to 25V
4V to 7V
C
PACKAGE/ORDER I FOR ATIO
Consult LTC Marketing for parts specified with wider operating temperature ranges.
= 0.4V
BOOST1
BOOST2
BOOST
T
JMAX
SW1
SW2
V
V
V
V
IN
IN
IN
IN
EXPOSED PAD (PIN 17) IS GND
MUST BE SOLDERED TO PCB
= 125 C,
16-LEAD PLASTIC TSSOP
= 8V unless otherwise noted. (Note 2)
1
2
3
4
5
6
7
8
FE PACKAGE
TOP VIEW
JA
= 45 C/W,
17
16
15
14
13
12
11
10
9
JC
= 10 C/W
FB1
V
PG1
RUN/SS1
RUN/SS2
PG2
V
FB2
C1
C2
1.230
1.225
1.215
0.95
MIN
150
78
1
U
1.250
1.250
1.250
0.005
0.005
0.75
TYP
240
330
180
180
3.4
3.8
2.4
1.8
1.1
1.1
0.5
30
42
60
88
ORDER PART
LT1940EFE
LT1940LEFE
1940EFE
1940LEFE
MARKING
NUMBER
FE PART
W
1.270
1.270
1.270
MAX
1200
1.25
1.35
210
3.6
4.8
45
uMhos
UNITS
1940fa
U
MHz
MHz
%/V
%/V
Deg
A/V
mA
nA
%
V
A
V
V
V
A
A
V
V
V