LT1945 LINER [Linear Technology], LT1945 Datasheet - Page 2

• Manufacturer Part Number: LT1945
• Description: Dual Micropower DC/DC Converter with Positive and Negative Outputs
• Manufacturer: LINER [Linear Technology]

LT1945
ABSOLUTE AXI U RATI GS
(Note 1)
V
SW1, SW2 Voltage .................................................. 36V
NFB1 Voltage ........................................................... –3V
FB2 Voltage ...............................................................V
Current into NFB1 Pin ........................................... –1mA
Current into FB2 Pin .............................................. 1mA
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
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifications are at T
PARAMETER
Minimum Input Voltage
Quiescent Current, (per Converter)
NFB1 Comparator Trip Point
FB2 Comparator Trip Point
FB Comparator Hysteresis
NFB1, FB2 Voltage Line Regulation
NFB1 Pin Bias Current (Note 3)
FB2 Pin Bias Current (Note 4)
Switch Off Time, Switcher 1 (Note 5)
Switch Off Time, Switcher 2 (Note 5)
Switch V
Switch Current Limit
SHDN Pin Current
SHDN Input Voltage High
SHDN Input Voltage Low
Switch Leakage Current
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LT1945 is guaranteed to meet performance specifications
from 0 C to 70 C. Specifications over the – 40 C to 85 C operating
2
IN
, SHDN1, SHDN2 Voltage ................................... 15V
CESAT
W
W W
CONDITIONS
Not Switching
V
1.2V < V
V
V
V
V
I
V
V
Switch Off, V
SW
SHDN
NFB1
FB2
FB2
FB2
SHDN
SHDN
= 300mA
= 1.23V
> 1V
< 0.6V
= –1.23V
= 0V
= 1.2V
= 5V
IN
< 12V
SW
U
= 5V
A
= 25 C. V
The
IN
IN
denotes the specifications which apply over the full operating
= 1.2V, V
PACKAGE/ORDER I FOR ATIO
Consult LTC Marketing for parts specified with wider operating temperature ranges.
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: Bias current flows out of the NFB1 pin.
Note 4: Bias current flows into the FB2 pin.
Note 5: See Figure 1 for Switcher 1 and Switcher 2 locations.
SHDN1
SHDN2
SHDN
NFB1
GND
FB2
T
JMAX
10-LEAD PLASTIC MSOP
= 1.2V unless otherwise noted.
1
2
3
4
5
= 125 C,
MS PACKAGE
TOP VIEW
JA
= 160 C/W
10
9
8
7
6
SW1
PGND
V
PGND
SW2
–1.205
IN
1.205
MIN
250
1.3
0.9
U
MS PART MARKING
–1.23
1.23
0.05
0.01
TYP
400
400
250
350
1.5
20
30
8
2
2
8
ORDER PART
LT1945EMS
NUMBER
W
LTTS
–1.255
1.255
MAX
0.25
350
400
1.2
0.1
2.9
30
80
12
1
3
5
UNITS
U
1945f
%/V
mV
mV
mA
nA
ns
ns
V
A
A
V
V
A
A
A
V
V
A
s