step-down DC/DC converter. Intended for medium power
applications, it operates from a 2.5V to 5.5V input voltage
range and has a user configurable operating frequency
up to 4MHz, allowing the use of tiny, low cost capacitors
and inductors 1mm or less in height. The output voltage is
adjustable from 0.6V to 5.5V. Internal synchronous power
switches provide high efficiency. The LTC3565’s current
mode architecture and external compensation allow the
transient response to be optimized over a wide range of
loads and output capacitors.
The LTC3565 can be configured for automatic power
saving Burst Mode operation (I
Q
= 40μA) to reduce gate
charge losses when the load current drops below the level
required for continuous operation. For reduced noise and
RF interference, the SYNC/MODE pin can be configured to
skip pulses or provide forced continuous operation.
To further maximize battery life, the P-channel MOSFET
is turned on continuously in dropout (100% duty cycle).
In shutdown, the device draws <1μA.
, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology
Corporation. All other trademarks are the property of their respective owners. Protected by
U.S. Patents, including 5481178, 6580258, 6498466, 6611131.
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High Efficiency: Up to 95%
V
IN
Range: 2.5V to 5.5V
High Frequency Operation: Up to 4MHz
Selectable Low Ripple (Typical 25mV
p-p
)
Burst Mode
®
Operation: I
Q
= 40μA
Stable with Ceramic Capacitors
Uses Tiny Capacitors and Inductor
Low R
DS(ON)
Internal Switches: 0.15Ω
Current Mode Operation for Excellent Line
and Load Transient Response
Short-Circuit Protected
Low Dropout Operation: 100% Duty Cycle
Low Shutdown Current: I
Q
≤ 1μA
Output Voltages from 0.6V to 5V
Synchronizable to External Clock
Supports Pre-Biased Outputs
Small 10-Lead (3mm
×
3mm) DFN or MSOP Package
APPLICATIONS
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Notebook Computers
Digital Cameras
Cellular Phones
Handheld Instruments
Board Mounted Power Supplies
TYPICAL APPLICATION
Step-Down 2.5V/1.25A Regulator
V
IN
2.5V TO 5.5V
22μF
EFFICIENCY (%)
SYNC/MODE SV
IN
PV
IN
RUN
PGOOD
ITH
RT
12.1k
V
FB
GND
680pF
191k
22pF
LTC3565
SW
2.2μH
V
OUT
2.5V
1.25A
22μF
Efficiency and Power Loss vs Output Current
100
90
80
70
60
50
40
30
20
V
IN
= 2.7V
V
IN
= 3.6V
V
IN
= 4.2V
1
10
100
1000
OUTPUT CURRENT (mA)
0.01
0.1
POWER LOSS (W)
1
0.001
931k
294k
10
0
0.1
0.0001
10000
3565 TA01b
3565 TA01a
3565f
1
LTC3565
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PV
IN
, SV
IN
Voltages ..................................... –0.3V to 6V
V
FB
, ITH, RT Voltages ....................–0.3V to (V
IN
+ 0.3V)
SYNC/MODE, PGOOD Voltage .......–0.3V to (V
IN
+ 0.3V)
SW Voltage (DC) ...........................–0.3V to (V
IN
+ 0.3V)
RUN Voltage ............................................... –0.3V to 6V
Operating Junction Temperature Range
(Notes 2, 5, 8) ........................................ –40°C to 125°C
Storage Temperature Range................... –65°C to 125°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
PIN CONFIGURATION
TOP VIEW
RT
RUN
SYNC/MODE
SW
GND
1
2
3
4
5
11
10 ITH
9 V
FB
8 PGOOD
7 SV
IN
6 PV
IN
TOP VIEW
RT
RUN
SYNC/MODE
SW
GND
1
2
3
4
5
10
9
8
7
6
ITH
V
FB
PGOOD
SV
IN
PV
IN
11
DD PACKAGE
10-LEAD (3mm × 3mm) PLASTIC DFN
T
JMAX
= 125°C,
θ
JA
= 43°C/W,
θ
JC
= 7.5°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
MSE PACKAGE
10-LEAD PLASTIC MSOP
T
JMAX
= 125°C,
θ
JA
= 40°C/W,
θ
JC
= 10°C/W
EXPOSED PAD (PIN 11) IS GND, MUST BE SOLDERED TO PCB
ORDER INFORMATION
LEAD FREE FINISH
LTC3565EDD#PBF
LTC3565IDD#PBF
LTC3565EMSE#PBF
LTC3565IMSE#PBF
TAPE AND REEL
LTC3565EDD#TRPBF
LTC3565IDD#TRPBF
LTC3565EMSE#TRPBF
LTC3565IMSE#TRPBF
PART MARKING*
LTDNR
LTDNR
LTDVJ
LTDVJ
PACKAGE DESCRIPTION
10-Lead (3mm × 3mm) Plastic DFN
10-Lead (3mm × 3mm) Plastic DFN
10-Lead Plastic MSOP
10-Lead Plastic MSOP
TEMPERATURE RANGE
–40°C to 125°C
–40°C to 125°C
–40°C to 125°C
–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/
The
●
denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
PCB设计
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