LTC1174
LTC1174-3.3/LTC1174-5
High Efficiency
Step-Down and Inverting
DC/DC Converter
FEATURES
DESCRIPTIO
High Efficiency: Up to 94% The LTC 1174 is a simple current mode DC/DC converter
Peak Inductor Current Independent of ideally suited for 9V to 5V, 5V to 3.3V or 5V to 5V
Inductor Value operation. With an internal 0.9 switch (at a supply
Short-Circuit Protection voltage of 9V), the LTC1174 requires only four external
Optimized for 5V to 5V Applications components to construct a complete high efficiency
Wide V Range: 4V to 18.5V DC/DC converter.
IN
Low Dropout Operation
Under a no load condition the LTC1174 draws only 130A.
Low-Battery Detector
In shutdown, it draws a mere 1A making this converter
Pin Selectable Current Limit
ideal for current sensitive applications. In dropout, the
Internal 0.9 Power Switch: V = 9V
IN
internal P-channel MOSFET switch is turned on continu-
Only Four External Components Required
ously allowing the user to maximize the life of the battery
130A Standby Current
source.
Active Low Micropower Shutdown
The maximum inductor current of the LTC1174 family is
U
pin selectable to either 340mA or 600mA, optimizing
APPLICATIO S
efficiency for a wide range of applications. Operation up to
Distributed Power Systems 200kHz permits the use of small surface mount inductors
Step-Down Converters and capacitors.
Inverting Converters
For applications requiring higher output current or ultra-
Memory Backup Supply
high efficiency, see the LTC1148 data sheet.
Portable Instruments
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Battery-Powered Equipment
All other trademarks are the property of their respective owners.
TYPICAL APPLICATIO
High Efficiency Step-Down Converter LTC1174-5 Efficiency
100
V
IN
9V
15F* 95
+
6
V = 6V
25V IN
V
IN
3
3 8
90
LB SHUTDOWN
IN
V = 9V
IN
2 1
LB V
OUT OUT
85
7 5 5V
I SW
PGM
175mA
100H
LTC1174-5
+ 80
100F**
GND 1N5818
10V
L = 100H
4
75
V = 5V
OUT
1174 TA01
I = 0V
PGM
* (3) AVX TPSD156K025
70
** AVX TPSD107K010
1 10 100 200
COILTRONICS CTX100-4
LOAD CURRENT (mA)
1174 TA02
1174fe
1
EFFICIENCY (%)
U
ULTC1174
LTC1174-3.3/LTC1174-5
ABSOLUTE AXI U RATI GS (Note 1)
(Voltage Referred to GND Pin) Operating Temperature Range
Input Supply Voltage (Pin 6) LTC1174CX ............................................ 0C to 70C
LTC1174 ........................................... 0.3V to 13.5V LTC1174IX ........................................ 40C to 85C
LTC1174HV ...................................... 0.3V to 18.5V Junction Temperature (Note 2)............................ 125C
Switch Current (Pin 5) .............................................. 1A Storage Temperature Range ................ 65C to 150C
Switch Voltage (Pin 5) Lead Temperature (Soldering, 10 sec)................. 300C
LTC1174 ................................................. V 13.5V
IN
LTC1174HV ............................................ V 18.5V
IN
UUW
PACKAGE/ORDER I FOR ATIO
TOP VIEW
TOP VIEW
V (V *) 1 8 SHUTDOWN
V (V *) 1 8 SHUTDOWN OUT FB
OUT FB
LB 2 7 I
LB 2 I OUT PGM
7
OUT PGM
LB V
3 6
LB 3 6 V IN IN
IN IN
GND SW
GND SW 4 5
4 5
S8 PACKAGE
N8 PACKAGE
8-LEAD PLASTIC SO
8-LEAD PDIP
* ADJUSTABLE OUTPUT VERSION
* ADJUSTABLE OUTPUT VERSION
T = 125C, = 150C/W
T = 125C, = 110C/W
JMAX JA
JMAX JA
ORDER PART NUMBER ORDER PART NUMBER
S8 PART MARKING
LTC1174CN8 LTC1174CS8 1174
LTC1174CN8-3.3 LTC1174CS8-3.3 117433
LTC1174CN8-5 LTC1174CS8-5 117450
LTC1174IN8 LTC1174IS8 1174I
LTC1174HVCN8 LTC1174HVCS8 1174H
LTC1174HVCN8-3.3 LTC1174HVCS8-3.3 1174H3
LTC1174HVCN8-5 LTC1174HVCS8-5 1174H5
LTC1174HVIS8 1174HI
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking: