http://www.www.datasheet4u.com

900,000+ Datasheet PDF Search and Download

Datasheet4U offers most rated semiconductors datasheets pdf




Linear Technology Electronic Components Datasheet

LTC1771E Datasheet

Low Quiescent Current High Efficiency Step-Down DC/DC Controller

No Preview Available !

LTC1771E pdf
FEATURES
s Very Low Standby Current: 10µA
s Available in Space-Saving 8-Lead MSOP Package
s High Output Currents
s Wide VIN Range: 2.8V to 20V Operation
s VOUT Range: 1.23V to 18V
s High Efficiency: Over 93% Possible
s ±2% Output Accuracy
s Very Low Dropout Operation: 100% Duty Cycle
s Current Mode Operation for Excellent Line and
Load Transient Response
s Defeatable Burst ModeTM Operation
s Short-Circuit Protected
s Optional Programmable Soft-Start
s Micropower Shutdown: IQ = 2µA
U
APPLICATIO S
s Cellular Telephones and Wireless Modems
s 1- to 4-Cell Lithium-Ion-Powered Applications
s Portable Instruments
s Battery-Powered Equipment
s Battery Chargers
s Scanners
Final Electrical Specifications
LTC1771
Low Quiescent Current
High Efficiency Step-Down
DC/DC Controller
DESCRIPTIO
February 2000
The LTC®1771 is a high efficiency current mode step-
down DC/DC controller that draws as little as 10µA DC
supply current to regulate the output at no load while
maintaining high efficiency for loads up to several amps.
The LTC1771 drives an external P-channel power MOSFET
using a current mode, constant off-time architecture. An
external sense resistor is used to program the operating
current level. Current mode control provides short-circuit
protection, excellent transient response and controlled
start-up behavior. Burst Mode operation enables the
LTC1771 to maintain high efficiency down to extremely
low currents. Shutdown mode further reduces the supply
current to a mere 2µA. For low noise applications, Burst
Mode operation can be easily disabled with the MODE pin.
Wide input supply range of 2.8V to 18V (20V maximum)
and 100% duty cycle operation for low dropout make the
LTC1771 ideal for a wide variety of battery-powered appli-
cations where maximizing battery life is important.
The LTC1771’s availability in both 8-lead MSOP and SO
packages provides for a minimum area solution.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
CSS
0.01µF
VIN
4.5V TO 18V
RSENSE
0.05
10µF
25V
CER
RC
10k
CC
22OpF
VIN SENSE
RUN/SS PGATE
ITH LTC1771
VFB MODE
GND
M1
Si6447DQ
VIN
R2
1.64M
1%
R1
1M
1%
5pF
L1
15µH
UPS5817
VOUT
3.3V
+ COUT 2A
150µF
6.3V
1771 F01
Figure 1. High Efficiency Step-Down Converter
LTC1771 Efficiency
100
VIN = 5V
90 VIN = 10V
80 VIN = 15V
70
60
50
VOUT = 3.3V
40 RSENSE = 0.05
0.1 1
10
100 1000
LOAD CURRENT (mA)
10000
1771 F01b
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
1


Linear Technology Electronic Components Datasheet

LTC1771E Datasheet

Low Quiescent Current High Efficiency Step-Down DC/DC Controller

No Preview Available !

LTC1771E pdf
LTC1771
ABSOLUTE AXI U RATI GS (Note 1)
Input Supply Voltage (VIN)........................ – 0.3V to 20V
Peak Driver Output Current < 10µs (PGATE) ............. 1A
RUN/SS Voltage ........................... – 0.3V to (VIN + 0.3V)
MODE Voltage .......................................... – 0.3V to 20V
ITH, VFB Voltage .......................................... – 0.3V to 5V
SENSE Voltage (VIN > 12V)... (VIN – 12V) to (VIN + 0.3V)
SENSE Voltage (VIN 12V) .......... – 0.3V to (VIN + 0.3V)
Junction Temperature (Note 2) ............................ 125°C
Operating Temperature Range (Note 3)
LTC1771E ......................................... – 40°C to 85°C
LTC1771I ......................................... – 40°C to 85°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
UW U
PACKAGE/ORDER I FOR ATIO
TOP VIEW
RUN/SS 1
ITH 2
VFB 3
GND 4
8 MODE
7 SENSE
6 VIN
5 PGATE
MS8 PACKAGE
8-LEAD PLASTIC MSOP
TJMAX = 125°C, θJA = 150°C/ W
ORDER PART
NUMBER
LTC1771EMS8
MS8 PART MARKING
LTKD
TOP VIEW
RUN/SS 1
ITH 2
VFB 3
GND 4
8 MODE
7 SENSE
6 VIN
5 PGATE
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 125°C, θJA = 110°C/ W
ORDER PART
NUMBER
LTC1771ES8
LTC1771IS8
S8 PART MARKING
1771
1771I
Consult factory for Military grade parts.
ELECTRICAL CHARACTERISTICS
The q denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.
VIN = 10V, VRUN = open unless otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN TYP MAX
VFB
IFB
ISUPPLY
VLINEREG
VLOADREG
IQ
VSENSE(MAX)
VSENSE(MIN)
VSENSE(SLEEP)
tOFF
Feedback Voltage
Feedback Current
No-Load Supply Current
Reference Voltage Line Regulation
Output Voltage Load Regulation
Input DC Supply Current
Active Mode (PGATE = 0V)
Sleep Mode (Note 6)
Shutdown
Short Circuit
Maximum Current Sense Threshold
Minimum Current Sense Threshold
Sleep Current Sense Threshold
Switch Off Time
VMODE
Mode Pin Threshold
(Note 5)
(Note 5)
VIN = 10V, ILOAD = 0 (Note 6)
VIN = 5V to 15V (Note 5)
ITH = 0.5V to 2V, Burst Disabled (Note 5)
(Note 4)
VIN = 2.8V to 18V
VIN = 2.8V to 18V, VFB = 1.5V
VIN = 2.8V to 18V, VRUN = 0V
VIN = 2.8V to 18V, VFB = 0V
VFB = VREF – 20mV
VFB = VREF + 10mV, Burst Disabled
ITH = 1V
VFB at Regulated Value
VFB = 0V
VMODE Rising
q 1.205
q
q
q
1.230
1
10
0.003
0.25
1.255
10
0.03
1
150 235
9 15
26
175 275
q 110 140 180
– 25
50
3.5
70
q 0.5
1.3
2
UNITS
V
nA
µA
%/V
%
µA
µA
µA
µA
mV
mV
mV
µs
µs
V
2


Part Number LTC1771E
Description Low Quiescent Current High Efficiency Step-Down DC/DC Controller
Maker Linear Technology
Total Page 16 Pages
PDF Download
LTC1771E pdf
Download PDF File
LTC1771E pdf
View for Mobile



Buy Electronic Components




Related Datasheet

1 LTC1771 High Efficiency Step-Down DC/DC Controller Linear Technology
Linear Technology
LTC1771 pdf
2 LTC1771E Low Quiescent Current High Efficiency Step-Down DC/DC Controller Linear Technology
Linear Technology
LTC1771E pdf






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