Datasheet

LT1938
2
1938fa
ELECTRICAL ChARACTERISTICS
V
IN
, RUN/SS Voltage .................................................25V
BOOST Pin Voltage ...................................................50V
BOOST Pin Above SW Pin .........................................25V
FB, RT, V
C
Voltage .......................................................5V
BIAS, PG, BD Voltage ................................................ 25V
Operating Junction Temperature Range (Note 2)
LT1938E ............................................. –40°C to 125°C
LT1938I .............................................. –40°C to 125°C
Storage Temperature Range ................... –65°C to 150°C
PARAMETER CONDITIONS MIN TYP MAX UNITS
Minimum Input Voltage
●
3 3.6 V
Quiescent Current from V
IN
V
RUN/SS
= 0.2V 0.01 0.5 µA
V
BIAS
= 3V, Not Switching
●
0.4 0.8 mA
V
BIAS
= 0, Not Switching 1.2 2.0 mA
Quiescent Current from BIAS V
RUN/SS
= 0.2V 0.01 0.5 µA
V
BIAS
= 3V, Not Switching
●
0.85 1.5 mA
V
BIAS
= 0, Not Switching 0 0.1 mA
Minimum Bias Voltage 2.7 3 V
Feedback Voltage
●
1.25
1.24
1.265
1.265
1.28
1.29
V
V
FB Pin Bias Current (Note 3)
●
30 100 nA
FB Voltage Line Regulation 4V < V
IN
< 25V 0.002 0.02 %/V
The ● denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 10V, V
RUN/SS
= 10V, V
BOOST
= 15V, V
BIAS
= 3.3V unless otherwise
noted. (Note 2)
AbSOLUTE MAxIMUM RATINgS
(Note 1)
PIN CONFIgURATION
TOP VIEW
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
10
9
6
7
8
4
5
3
11
2
1
RT
V
C
FB
BIAS
PG
BD
BOOST
SW
V
IN
RUN/SS
T
JMAX
= 125°C, θ
JA
= 45°C/W, θ
JC
= 10°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE
LT1938EDD#PBF LT1938EDD#TRPBF LDFT 10-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
LT1938IDD#PBF LT1938IDD#TRPBF LDFT 10-Lead (3mm × 3mm) Plastic DFN –40°C to 125°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/