nous buck regulator using a constant frequency, current
mode architecture. Supply current during operation is
only 20μA, dropping to
≤1μA
in shutdown. The 2.5V to
5.5V input voltage range makes the LTC3564 ideally suited
for single Li-Ion battery-powered or 3.3V to 5V input
voltage applications. 100% duty cycle provides low drop-
out operation, extending battery life in portable systems.
Automatic Burst Mode
®
operation increases efficiency at
light loads, further extending battery runtime.
Switching frequency is internally set at 2.25MHz, allowing
the use of small surface mount inductors and capacitors.
The internal synchronous switch increases efficiency and
eliminates the need for an external Schottky diode. Low
output voltages are easily supported with the 0.6V feed-
back reference voltage. The LTC3564 is available in low
profile (1mm) ThinSOT and 6-Lead (2mm
×
3mm) DFN
packages.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation.
ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents including 5481178, 6580258, 6304066, 6498466, 6611131.
APPLICATIO S
■
■
■
■
■
■
Cellular Telephones
Wireless and DSL Modems
Digital Still Cameras
Media Players
Portable Instruments
Point of Load Regulation
TYPICAL APPLICATIO
100
90
80
EFFICIENCY (%)
70
60
50
40
30
20
10
V
OUT
= 1.8V
1.1μH
V
IN
C
IN
22μF
CER
V
IN
SW
22pF
C
OUT
22μF
CER
634k
316k
3564 TA01a
V
OUT
1.8V
LTC3564
RUN
GND
V
FB
0
0.1
1
10
100
1000
OUTPUT CURRENT (mA)
U
10
1
POWER LOSS (W)
0.1
0.01
0.001
V
IN
= 2.7V
V
IN
= 3.6V
V
IN
= 4.2V
0.0001
0.00001
10000
3564 TA01b
U
U
3564f
1
LTC3564
ABSOLUTE
AXI U RATI GS
(Note 1)
Operating Junction Temperature Range
(Notes 2, 3, 6) ...................................... – 40°C to 125°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
Input Supply Voltage .................................. – 0.3V to 6V
RUN, V
FB
Voltages ..................................... – 0.3V to V
IN
SW Voltage (DC) ......................... – 0.3V to (V
IN
+ 0.3V)
PI CO FIGURATIO
TOP VIEW
V
FB
1
GND 2
V
IN
3
5 RUN
4 SW
S5 PACKAGE
5-LEAD PLASTIC TSOT-23
T
JMAX
= 125°C,
θ
JA
= 215°C/ W,
θ
JC
= 50°C/ W
ORDER I FOR ATIO
LEAD FREE FINISH
LTC3564ES5#PBF
LTC3564IS5#PBF
LTC3564EDCB#PBF
LTC3564IDCB#PBF
TAPE AND REEL
LTC3564ES5#TRPBF
LTC3564IS5#TRPBF
LTC3564EDCB#TRPBF
LTC3564IDCB#TRPBF
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 nonstandard 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/
ELECTRICAL CHARACTERISTICS
The
●
denotes specifications which apply over the full operating junction temperature range, otherwise specifications are T
A
= 25°C.
V
IN
= 3.6V unless otherwise specified.
SYMBOL
I
VFB
V
FB
ΔV
FB
I
PK
V
LOADREG
V
IN
PARAMETER
Feedback Current
Regulated Feedback Voltage
Reference Voltage Line Regulation
Peak Inductor Current
Output Voltage Load Regulation
Input Voltage Range
●
CONDITIONS
●
(Note 4)
V
IN
= 2.5V to 5.5V (Note 4)
V
IN
= 3V, V
FB
= 0.5V, Duty Cycle < 35%
2
U
U
W W
U
W
W
U
U
U
TOP VIEW
SW 1
PGND 2
V
IN
3
7
6 RUN
5 SGND
4 V
FB
DCB PACKAGE
6-LEAD (2mm
×
3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 64°C/ W,
θ
JC
= 10.6°C/ W
EXPOSED PAD (PIN 7) IS SGND, MUST BE SOLDERED TO PCB
PART MARKING*
LTCYJ
LTCYJ
LDTQ
LDTQ
PACKAGE DESCRIPTION
5-Lead Plastic TSOT-23
5-Lead Plastic TSOT-23
6-Lead (2mm
×
3mm) Plastic DFN
6-Lead (2mm
×
3mm) Plastic DFN
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
MIN
●
TYP
0.6
0.04
2.0
0.5
MAX
±30
0.6120
0.4
2.5
5.5
UNITS
nA
V
%/V
A
%
V
0.5880
1.5
2.5
3564f
LTC3564
ELECTRICAL CHARACTERISTICS
The
●
denotes specifications which apply over the full operating junction temperature range, otherwise specifications are T
A
= 25°C.
V
IN
= 3.6V unless otherwise specified.
SYMBOL
I
S
PARAMETER
Input DC Bias Current
Active Mode
Sleep Mode
Shutdown
Oscillator Frequency
R
DS(ON)
of P-Channel FET
R
DS(ON)
of N-Channel FET
SW Leakage
RUN Threshold
RUN Leakage Current
Soft-Start Time
V
FB
from 10% to 90% Full Scale
CONDITIONS
(Note 5)
V
FB
= 0.5V or V
OUT
= 90%, I
LOAD
= 0A
V
FB
= 0.62V or V
OUT
= 103%, I
LOAD
= 0A
V
RUN
= 0V, V
IN
= 4.2V
V
FB
= 0.6V or V
OUT
= 100%
S5 Package
DCB Package
S5 Package
DCB Package
V
RUN
= 0V, V
SW
= 0V or 5V, V
IN
= 5V
●
●
●
MIN
TYP
300
20
0.1
MAX
400
35
1
2.7
0.2
0.2
±1
1.5
±1
1.2
UNITS
μA
μA
μA
MHz
Ω
Ω
Ω
Ω
μA
V
μA
ms
f
OSC
R
PFET
R
NFET
I
LSW
V
RUN
I
RUN
t
SOFTSTART
1.8
2.25
0.15
0.15
0.15
0.15
±0.01
0.3
0.6
1
±0.01
0.9
Note 1:
Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliabilty and lifetime.
Note 2:
The LTC3564E is guaranteed to meet performance specifications
from 0°C to 125°C junction temperature. Specifications over the –40°C to
125°C operating junction termperature range are assured by design,
characterization and correlation with statistical process controls. The
LTC3564I is guaranteed over the full –40°C to 125°C operating junction
temperature range. High junction temperatures degrade operating
lifetimes. Operating lifetime is derated at junction temperatures greater
than 125°C.
Note 3:
T
J
is calculated from the ambient temperature T
A
and power
dissipation P
D
according to the following formula:
LTC3564ES5: T
J
= T
A
+ (P
D
)(215°C/W)
LTC3564EDCB: T
J
= T
A
+ (P
D
)(64°C/W)
Note 4:
The LTC3564 is tested in a proprietary test mode.
Note 5:
Dynamic supply current is higher due to the gate charge being
delivered at the switching frequency.
Note 6:
This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. Junction
temperature will exceed 125°C when overtemperature protection is active.
Continuous operation above the specified maximum operating junction
近几年发光二极管( LED )的应用在不断增长，其市场覆盖范围很广，包括像指示灯、聚光灯和头灯这样的汽车照明应用，像显示背光和照相机闪光灯这样的照相功能，像LED显示器背光和投射系统这样的消费产品，像建筑物的特色照明和标志这样的建筑应，以及许多其他方面的应用。LED亮度高、发光效率高且反应速度快。由于耗能低，使用寿命长，放热少且可发出彩色光的特点，已经在很多方面替代了白炽灯。 随着LED效率...[详细]
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