900,000+ datasheet pdf search and download

Datasheet4U offers most rated semiconductors data sheet pdf




Linear Technology Electronic Components Datasheet

LT1949 Datasheet

600kHz/ 1A Switch PWM DC/DC Converter

No Preview Available !

FEATURES
s 1A, 0.5, 30V Internal Switch
s Operates with VIN as Low as 1.5V
s 600kHz Fixed Frequency Operation
s Low-Battery Detector Stays Active in Shutdown
s Low VCESAT Switch: 410mV at 800mA
s Pin-for-Pin Compatible with the LT1317B
s Small 8-Lead MSOP and SO Packages
U
APPLICATIO S
s LCD Bias Supplies
s GPS Receivers
s Battery Backup
s Portable Electronic Equipment
s Diagnostic Medical Instrumentation
LT1949
600kHz, 1A Switch
PWM DC/DC Converter
DESCRIPTIO
The LT®1949 is a fixed frequency step-up DC/DC con-
verter with a 1A, 0.5internal switch. Capable of gener-
ating 10V at 175mA from a 3.3V input, the LT1949 is ideal
for generating bias voltages for large screen LCD panels.
Constant frequency 600kHz operation results in a low
noise output that is easy to filter and the 30V switch rating
allows output voltage up to 28V using a single inductor. An
external compensation pin gives the user flexibility in
optimizing loop compensation, allowing small low ESR
ceramic capacitors to be used at the output. The 8-lead
MSOP and SO packages ensure a low profile overall
solution.
The LT1949 includes a low-battery detector that stays
alive when the device goes into shutdown. Quiescent
current in shutdown is 25µA, while operating current is
4.5mA.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
VIN
3.3V
+
C1
22µF
SHUTDOWN
L1
10µH
VIN SW
LT1949
SHDN
FB
VC GND
68k
330pF
D1
R1
1M
R2
140k
VOUT
10V
175mA
C2
10µF
CERAMIC
C1: AVX TAJA226M006R
C2: TAIYO YUDEN LMK325BJ106MN
D1: MBRM120LT3
L1: SUMIDA CDRH62B-100
1949 F01
Figure 1. 3.3V to 10V/175mA DC/DC Converter
90
VOUT = 10V
80
70
3.6VIN 4.2VIN 3VIN
60
50
40
30
20
5
10 50 100
LOAD CURRENT (mA)
300
1949 F02
Figure 2. 3.3V to 10V Converter Efficiency
1


Linear Technology Electronic Components Datasheet

LT1949 Datasheet

600kHz/ 1A Switch PWM DC/DC Converter

No Preview Available !

LT1949
ABSOLUTE AXI U RATI GS (Note 1)
VIN, LBO Voltage ..................................................... 12V
SW Voltage ............................................... – 0.4V to 30V
FB Voltage .................................................... VIN + 0.3V
VC Voltage ................................................................ 2V
LBI Voltage ............................................ 0V VLBI 1V
SHDN Voltage ........................................................... 6V
Junction Temperature .......................................... 125°C
Operating Temperature Range (Note 2)
LT1949EMS8 .......................................–40°C to 85°C
LT1949ES8/LT1949IS8 .......................–40°C to 85°C
Storage Temperature ........................... – 65°C to 150°C
Lead Temperature (Soldering, 10sec).................. 300°C
UW U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
VC 1
FB 2
SHDN 3
GND 4
8 LBO
7 LBI
6 VIN
5 SW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
TJMAX = 125°C, θJA = 120°C/W
ORDER PART
NUMBER
LT1949EMS8
MS8 PART MARKING
LTJC
Consult factory for Military grade parts.
TOP VIEW
VC 1
FB 2
SHDN 3
GND 4
8 LBO
7 LBI
6 VIN
5 SW
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 125°C, θJA = 120°C/W
ORDER PART
NUMBER
LT1949ES8
LT1949IS8
S8 PART MARKING
1949E
1949I
ELECTRICAL CHARACTERISTICS The q denotes specifications which apply over the full operating
temperature range, otherwise specifications are TA = 25°C. VIN = 2V, VSHDN = 2V unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN TYP MAX
IQ Quiescent Current
VFB Feedback Voltage
VSHDN = 0V
q 4.5 7.5
q 25 40
1.22 1.24 1.26
q 1.20 1.24 1.26
IB FB Pin Bias Current (Note 3)
Input Voltage Range
q 12 80
q 1.7
12
gm Error Amp Transconductance
AV Error Amp Voltage Gain
Maximum Duty Cycle
I = 5µA
q 70
q 80
140 240
700
85
Switch Current Limit (Note 4)
fOSC Switching Frequency
Shutdown Pin Current
LBI Threshold Voltage
VIN = 2.5V, Duty Cycle = 30%
VIN = 2.5V, Duty Cycle = 30%
VSHDN = VIN
VSHDN = 0V
1
q 0.95
q 500
q
q
190
q 180
1.13
600
0.015
– 2.3
200
200
1.5
1.5
750
0.1
–7
210
220
LBO Output Low
LBO Leakage Current
LBI Input Bias Current (Note 5)
Low-Battery Detector Gain
ISINK = 10µA
VLBI = 250mV, VLBO = 5V
VLBI = 150mV
1MPull-Up
q
q
q
0.15 0.25
0.02 0.1
5 60
2000
Switch Leakage Current
VSW = 5V
q 0.01 3
UNITS
mA
µA
V
V
nA
V
µmhos
V/V
%
A
A
kHz
µA
µA
mV
mV
V
µA
nA
V/V
µA
2


Part Number LT1949
Description 600kHz/ 1A Switch PWM DC/DC Converter
Maker Linear Technology
PDF Download

LT1949 Datasheet PDF






Similar Datasheet

1 LT1940 1.1MHz Step-Down Switching Regulator
Linear Technology
2 LT1940L 1.1MHz Step-Down Switching Regulator
Linear
3 LT1941 Triple Monolithic Switching Regulator
Linear Technology
4 LT1942 Quad DC/DC Converter
Linear
5 LT1943 High Current Quad Output Regulator
Linear
6 LT1944-1 Dual Micropower Step-Up DC/DC Converter
Linear
7 LT1945 Dual Micropower DC/DC Converter
Linear Technology
8 LT1946 1.2MHz Boost DC/DC Converter
Linear Technology
9 LT1946A 2.7MHz Boost DC/DC Converter
Linear Technology





Part Number Start With

0    1    2    3    4    5    6    7    8    9    A    B    C    D    E    F    G    H    I    J    K    L    M    N    O    P    Q    R    S    T    U    V    W    X    Y    Z

Site map

Webmaste! click here

Contact us

Buy Components

Privacy Policy