1
LTC3525-3.3/LTC3525-5
3525f
MP3 Players
Portable Instruments
Glucose Meters
Digital Cameras
400mA Micropower
Synchronous Step-Up DC/DC
Converter with Output Disconnect
Up to 95% Efficiency
Output Disconnect and Inrush Current Limit
Fixed Output Voltages of 3.3V or 5V
Delivers 60mA at 3.3V from a 1V Input,
or 140mA at 3.3V from a 1.8V Input
Delivers 175mA at 5V from a 3V Input
Burst Mode
Operation: I
Q
= 7
A
Only Three External Components
1V to 4.5V Input Range
<1
A Shutdown Current
Antiringing Control
Short-Circuit and Overtemperature Protection
Very low profile of 1mm
Tiny 6-Pin SC-70 Package
LTC3525-3.3 Efficiency and Power
Loss vs Load Current
FEATURES
APPLICATIO S
U
TYPICAL APPLICATIO
U
The LTC
3525-3.3/LTC3525-5 are high efficiency syn-
chronous step-up DC/DC converters with output discon-
nect that can start up with an input as low as 1V. They offer
a compact, high efficiency alternative to charge pumps in
single cell or dual cell alkaline or Li-ion applications. Only
three small external components are required. The LTC3525
is offered in fixed output voltages of 3.3V or 5V.
The device includes a 0.5
N-channel MOSFET switch and
a 0.8
P-channel synchronous rectifier. Peak switch
current ranges from 150mA to 400mA, depending on load,
providing enhanced efficiency. Quiescent current is an
ultralow 7
A, maximizing battery life in portable applica-
tions.
Other features include <1
A shutdown current, anti-
ringing control and thermal shutdown. The LTC3525 is
available in a tiny 6-pin SC-70 package.
L1*
10
H
3525 TA01
LTC3525-3.3
*MURATA LQH32CN100K53
V
OUT
3.3V
60mA
V
OUT
GND
SW
SHDN
GND
V
IN
V
IN
1V to 1.6V
10
F
1
F
OFF ON
LOAD (mA)
0.01
0.1
EFFICIENCY (%)
100
90
80
70
60
50
40
30
20
POWER LOSS (mW)
100
10
1
0.1
0.01
1
10
1000
100
LT3525 TA02
EFFICIENCY
POWER LOSS
V
IN
= 3V
V
IN
= 2.4V
V
IN
= 1.2V
DESCRIPTIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
Burst Mode is a registered trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Patents Pending
2
LTC3525-3.3/LTC3525-5
3525f
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Input Start-Up Voltage
0.85
1
V
Output Voltage
(Note 6)
3.20
3.30
3.40
V
Quiescent Current, V
OUT
SHDN = V
IN
(Note 4)
7
15
A
Quiescent Current, V
IN
SHDN = V
IN
(Note 4)
0.5
3
A
Quiescent Current, V
IN
- Shutdown
SHDN = 0V, V
OUT
= 0V
0.1
1
A
Not Including Switch Leakage
NMOS Switch Leakage
V
IN
= V
OUT
= V
SW
= 5V, SHDN = 0V
0.1
1
A
PMOS Switch Leakage
V
IN
= V
SW
= 5V, V
OUT
= 0V, SHDN = 0V
0.1
3
A
NMOS Switch On Resistance
0.5
PMOS Switch On Resistance
0.8
Peak Current Limit
0.4
0.45
A
SHDN Threshold
0.4
0.6
1
V
SHDN Input Current
V
SHDN
= V
IN
or V
OUT
0.01
1
A
V
IN
, V
OUT
Voltage ........................................ 0.3V to 6V
SW Voltage ................................................ 0.3V to 6V
SW Voltage < 100ns ................................... 0.3V to 7V
SHDN Voltage ............................................ 0.3V to 6V
Operating Temperature Range
(Notes 2, 5) ........................................ 40
C to 85C
Storage Temperature Range ................ 65
C to 125C
Lead Temperature (Soldering, 10 sec)................. 300
C
ABSOLUTE AXI U RATI GS
W
W
W
U
PACKAGE/ORDER I FOR ATIO
U
U
W
The
denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25
C.
V
IN
= 1.2V, V
SHDN
= 1.2V, V
OUT
= 3.3V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
(Note 1)
(LTC3525-3.3)
T
JMAX
= 125
C
JA
= 256
C/ W IN FREE AIR,
JA
= 150
C/ W ON BOARD
OVER GROUND PLANE
ORDER PART NUMBER
Consult LTC Marketing for parts specified with wider operating temperature ranges.
Order Options Tape and Reel: Add #TR
Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF
Lead Free Part Marking:
http://www.linear.com/leadfree/
LTC3525ESC6-3.3
LTC3525ESC6-5
SHDN
1
GND
2
V
IN
3
6
SW
5
GND
4 V
OUT
TOP VIEW
SC6 PACKAGE
6-LEAD PLASTIC SC70
SC6 PART MARKING
LBTG
LBWT
3
LTC3525-3.3/LTC3525-5
3525f
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Input Start-Up Voltage
0.85
1
V
Output Voltage
(Note 6)
4.85
5.00
5.15
V
Quiescent Current, V
OUT
SHDN = V
IN
8
18
A
Quiescent Current, V
IN
SHDN = V
IN
1.5
5
A
Quiescent Current, V
IN
- Shutdown
SHDN = 0V, V
OUT
= 0V
0.1
1
A
Not Including Switch Leakage
NMOS Switch Leakage
V
IN
= V
OUT
= V
SW
= 5V, SHDN = 0V
0.1
1
A
PMOS Switch Leakage
V
IN
= V
SW
= 5V, V
OUT
= 0V, SHDN = 0V
0.1
3
A
NMOS Switch On Resistance
0.4
PMOS Switch On Resistance
0.7
Peak Current Limit
0.4
0.5
A
SHDN Threshold
0.4
0.6
1
V
SHDN Input Current
V
SHDN
= V
IN
or V
OUT
0.01
1
A
The
denotes specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25
C.
V
IN
= 2.4V, V
SHDN
= 2.4V, V
OUT
= 5V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
Note 1: Absolute Maximum Ratings are those values beyond which the life
of the device may be impaired.
Note 2: The LTC3525E is guaranteed to meet performance specifications
from 0
C to 70C. Specifications over the 40C to 85C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: Specification is guaranteed by design and not 100% tested in
production.
Note 4: Current Measurements are performed when the LTC3525 is not
switching.
Note 5: 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
temperature may impair device reliability.
Note 6: Consult LTC Marketing for other output voltage options.
(LTC3525-5)
4
LTC3525-3.3/LTC3525-5
3525f
V
IN
(V)
0.5
1.0
I
OUT
(mA)
350
300
250
200
150
100
50
0
2.5
3.5
3525 G01
1.5
2.0
3.0
4.0
4.5
LTC3525-5
LTC3525-3.3
LOAD (mA)
0.01
0.1
EFFICIENCY (%)
100
90
80
70
60
50
40
30
20
POWER LOSS (mW)
100
10
1
0.1
0.01
1
10
1000
100
3525 G04
EFFICIENCY
POWER LOSS
V
IN
= 3V
V
IN
= 2.4V
V
IN
= 1.2V
3525 G02
250
200
150
100
50
0
LOAD (mA)
V
IN
(V)
0.5
1.0
1.5
2.0
2.5
3.0
LTC3525-3.3
LTC3525-5
3525 G03
V
IN
(V)
1.0
2.5
3.5
1.5
2.0
3.0
4.0
4.5
I
IN
(
A)
50
45
40
35
30
25
20
15
10
5
0
LTC3525-5
LTC3525-3.3
LOAD (mA)
0.01
0.1
EFFICIENCY (%)
100
90
80
70
60
50
40
30
20
10
0
POWER LOSS (mW)
1000
100
10
1
0.1
0.01
1
10
1000
100
3525 G05
EFFICIENCY
POWER LOSS
V
IN
= 3.6V
V
IN
= 2.4V
V
IN
= 1.2V
3525 G06
LOAD (mA)
0
40
60
20
10
30
50
70
80
CHANGE IN V
OUT
(%)
2.5
2.0
1.5
1.0
0.5
0
0.5
1.0
1.5
2.0
2.5
C
OUT
= 22
F
C
OUT
= 10
F
V
IN
= 1.2V
3525 G07
LOAD (mA)
0
140 160
120
100
20
40
60
80
180
CHANGE IN V
OUT
(%)
2.5
2.0
1.5
1.0
0.5
0
0.5
1.0
1.5
2.0
2.5
C
OUT
= 22
F
C
OUT
= 10
F
V
IN
= 2.4V
3525 G09
LOAD (mA)
0
120
100
20
40
60
80
140
CHANGE IN V
OUT
(%)
2.5
2.0
1.5
1.0
0.5
0
0.5
1.0
1.5
2.0
2.5
C
OUT
= 22
F
C
OUT
= 10
F
V
IN
= 2.4V
3525 G08
LOAD (mA)
0
40
20
10
30
50
60
CHANGE IN V
OUT
(%)
2.5
2.0
1.5
1.0
0.5
0
0.5
1.0
1.5
2.0
2.5
C
OUT
= 22
F
C
OUT
= 10
F
V
IN
= 1.2V
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
T
A
= 25
C unless otherwise noted.
Maximum Output Current vs V
IN
(for V
OUT
to Drop 2.5%)
Maximum Startup Load vs V
IN
(Resitive Load)
No-Load Input Current vs V
IN
LTC3525-3.3 Efficiency and Power
Loss vs Load
LTC3525-5 Efficiency and Power
Loss vs Load
LTC3525-3.3 Load Regulation
LTC3525-3.3 Load Regulation
LTC3525-5 Load Regulation
LTC3525-5 Load Regulation
5
LTC3525-3.3/LTC3525-5
3525f
1.0
2.5
3.5
1.5
2.0
3.0
4.0
4.5
3525 G14
120
100
80
60
40
20
0
SWITCHING DELAY (
s)
V
IN
(V)
3525 G12
LOAD (mA)
0.1
BURST FREQUENCY (kHz)
40
35
30
25
20
15
10
5
0
1
10
C
OUT
= 10
F
C
OUT
= 22
F
3525 G10
LOAD (mA)
0
150
50
200
100
CHANGE IN V
OUT
(%)
2.5
2.0
1.5
1.0
0.5
0
0.5
1.0
1.5
2.0
2.5
C
OUT
= 22
F
C
OUT
= 10
F
V
IN
= 3.6V
3525 G11
V
IN
(V)
1.0
2.5
3.5
1.5
2.0
3.0
4.0
4.5
FREQUENCY (kHz)
1200
1100
1000
900
800
700
600
500
400
300
LTC3525-5
LTC3525-3.3
L = 10
H
3525 G13
TEMPERATURE (
C)
40302010 0
CHANGE IN V
OUT
(%)
80
40 50
20
10
30
70
60
0.4
0.3
0.2
0.1
0.1
0.2
0.3
0.4
0
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
LTC3525-5 Load Regulation
Switching Frequency vs V
IN
Light Load Burst Frequency
vs Load
V
OUT
Variation vs Temperature
(Normalized to 25
C)
Startup Delay Coming Out of
Shutdown
LTC3525-3.3 Input Current and
V
OUT
at Startup
LTC3525-3.3 Output Voltage
Ripple
LTC3525-3.3 Output Voltage
Ripple
T
A
= 25
C unless otherwise noted.
3525 G15
INPUT
CURRENT
100mA/DIV
V
OUT
1V/DIV
500
s/DIV
V
IN
= 1.2V
3525 G16
50mV/DIV
I
OUT
=
80mA
I
OUT
=
40mA
I
OUT
=
5mA
50
s/DIV
V
IN
= 1.2V
C
OUT
= 10
F
3525 G17
I
OUT
=
80mA
I
OUT
=
40mA
I
OUT
=
5mA
50
s/DIV
V
IN
= 1.2V
C
OUT
= 22
F
50mV/DIV
6
LTC3525-3.3/LTC3525-5
3525f
TYPICAL PERFOR A CE CHARACTERISTICS
U
W
LTC3525-5 Output Voltage Ripple
LTC3525-5 Output Voltage Ripple
LTC3525-3.3 50mA Load Step
Response
LTC3525-3.3 100mA Load Step
Response
LTC3525-5 100mA Load Step
Response
T
A
= 25
C unless otherwise noted.
3525 G21
OUTPUT
RIPPLE
50mV/DIV
LOAD
CURRENT
20mA/DIV
V
IN
= 1.2V
C
OUT
= 22
F
500
s/DIV
3525 G22
OUTPUT
RIPPLE
50mV/DIV
LOAD
CURRENT
50mA/DIV
V
IN
= 2.4V
C
OUT
= 22
F
500
s/DIV
3525 G20
I
OUT
=
200mA
I
OUT
=
100mA
V
IN
= 3.6V
C
OUT
= 22
F
I
OUT
=
20mA
50
s/DIV
50mV/DIV
3525 G19
I
OUT
=
150mA
I
OUT
=
50mA
V
IN
= 2.4V
C
OUT
= 22
F
I
OUT
=
5mA
50
s/DIV
50mV/DIV
3525 G23
OUTPUT
RIPPLE
50mV/DIV
LOAD
CURRENT
50mA/DIV
V
IN
= 3.6V
C
OUT
= 22
F
500
s/DIV
LTC3525-3.3 Output Voltage
Ripple
3525 G18
I
OUT
=
190mA
I
OUT
=
100mA
I
OUT
=
5mA
50
s/DIV
V
IN
= 2.4V
C
OUT
= 22
F
50mV/DIV
7
LTC3525-3.3/LTC3525-5
3525f
U
U
U
PI FU CTIO S
_____
SHDN (Pin 1): Logic Controlled Shutdown Input. Connect
to a voltage >1V to enable the LTC3525. Connect to a
voltage <0.4V to disable the LTC3525.
GND (Pins 2, 5): Ground.
V
IN
(Pin 3): Input Voltage. The LTC3525 is powered from
V
IN
until V
OUT
exceeds V
IN
. Once V
OUT
is greater than (V
IN
+ 0.2V typical), it is powered from V
OUT
. Place a ceramic
bypass capacitor from V
IN
to GND. A minimum value of
1
F is recommended.
V
OUT
(Pin 4): Output Voltage Sense and the Output of the
Synchronous Rectifier. Connect the output filter capacitor
from V
OUT
to GND, close to the IC. A minimum value of
10
F ceramic is recommended. Use 22F for reduced
output ripple. The output disconnect feature disconnects
V
OUT
from V
IN
when SHDN is <0.4V.
SW (Pin 6): Switch Pin. Connect an inductor from this pin
to V
IN
. An internal antiringing resistor is connected across
SW and V
IN
after the inductor current has dropped to zero
to minimize EMI.
BLOCK DIAGRA
W
+
+
+
+
+
3
6
1
2
4
V
REF
I
PK
COMPARATOR
I
VALLEY
COMPARATOR
SLEEP
COMPARATOR
INTEGRATOR
WAKE
TSD
I
VAL
V
OUT
V
IN
SHDN
SW
I
PK
ADJUST
GND
FB
OFFSET
ADJUST
OFFSET
ADJUST
LOGIC
GATE DRIVERS
AND
ANTI-CROSS
CONDUCTION
WELL
SWITCH
V
BEST
V
REF
UVLO
THERMAL
SHUTDOWN
VB
SHUTDOWN
STARTUP
UVLO
SHUTDOWN
SHUTDOWN
V
REF
V
SEL
V
OUT
3525 BD
8
LTC3525-3.3/LTC3525-5
3525f
The LTC3525 is a high performance Burst Mode operation
only, synchronous boost converter requiring only three
small external components. Its simplicity and small size
make it a high efficiency alternative to charge pump
designs. It is designed to start up from a single alkaline or
nickel cell, with input voltages as low as 1V, or from two
or three cells (or a Li-ion battery), with voltages as high as
4.5V. Once started, V
IN
can be as low as 0.5V (depending
on load current) and maintain regulation. The output
voltage is preset internally to either 3.3V or 5V. Peak
switch current is 400mA minimum, providing regulation
with load currents up to 150mA, depending on input
voltage.
Synchronous rectification provides high efficiency opera-
tion while eliminating the need for an external Schottky
diode. True output disconnect eliminates inrush current at
start-up, and allows V
OUT
to be disconnected from V
IN
, for
zero shutdown current.
The output disconnect feature also allows the LTC3525 to
maintain regulation with an input voltage equal to or
greater than V
OUT
. Note, however, that the synchronous
rectifier is not enabled in this mode resulting in lower
efficiency and reduced output current capability.
The operating quiescent current is only 7
A typical, allow-
ing the converter to maintain high efficiency at extremely
light loads.
Shutdown
The LTC3525 is shut down by pulling SHDN below 0.4V,
and made active by raising it above 1V. Note that SHDN
can be driven as high as 6V, however, if it is more than 0.9V
above the higher of V
IN
or V
OUT
, the SHDN input current
will increase from zero to 1.5
A.
After the SHDN pin rises, there is a short delay before
switching starts. The delay is 20
s to 120s, depending on
input voltage (see Typical Performance Characteristics
curve).
Start-up
A start-up oscillator allows the LTC3525 to start with input
voltages as low as 1V. It remains in start-up mode until two
conditions are met. V
OUT
must exceed V
IN
by at least
0.2V typical and either V
IN
or V
OUT
must be greater than
1.8V typical.
During startup, the synchronous rectifier is not enabled,
and the internal P-channel synchronous rectifier acts as a
follower, causing the peak voltage on SW to reach (V
IN
+
1V) typical. This limits inrush current by maintaining
control of the inductor current when V
OUT
is less than V
IN
.
To reduce power dissipation in the P-channel synchro-
nous rectifier when the output is shorted, a foldback
feature is incorporated that reduces the peak inductor
current when V
IN
is more than 1.7V greater than V
OUT
.
Normal Operation
Once V
OUT
has increased more than 0.2V typical above
V
IN
, and either voltage is above 1.8V, normal operation
begins, with synchronous rectification enabled. In this
mode, the internal N-channel MOSFET connected between
SW and GND stays on until the inductor current reaches a
maximum peak value, after which it is turned off and the
P-channel synchronous rectifier is turned on. It stays on,
delivering current to the output, until the inductor current
has dropped below a minimum value at which point it
turns off and the cycle repeats. When the output voltage
reaches its regulated value both switches are turned off
and the LTC3525 goes to sleep, during which time the
output capacitor supplies current to the load. Once the
output voltage drops approximately 9mV below the regu-
lation value the IC leaves sleep mode and switching is
resumed.
The LTC3525 has been designed for low output voltage
ripple. The output voltage ripple is typically only 20mV
peak-to-peak at light load and 60mV peak-to-peak at full
OPERATIO
U
9
LTC3525-3.3/LTC3525-5
3525f
load using the minimum recommended 10
F output ca-
pacitor for the LTC3525-3.3 and a 22
F capacitor for the
LTC3525-5 (due to the capacitor's DC bias effect). An
antiring circuit damps any oscillation at the switch node
when the inductor current falls to zero.
Power Adjust Feature
The LTC3525 incorporates a feature that maximizes
efficiency at light load while providing increased power
capability at heavy load by adjusting the peak and valley of
the inductor current as a function of load. Lowering the
peak inductor current to 150mA at light load optimizes
efficiency by reducing conduction losses in the internal
MOSFET switches. As the load increases, the peak induc-
tor current is automatically increased to a maximum of
400mA. At intermediate loads, the peak inductor current
may vary from 150mA to 400mA. Figure 1 shows an
example of how the inductor current changes as the load
increases. Please note that output capacitor values greater
than 47
F will result in higher peak currents than neces-
sary at light load. This will lower the light load efficiency.
The valley of the inductor current is automatically adjusted
as well, to maintain a relatively constant inductor ripple
current. This keeps the switching frequency relatively
constant.
The maximum average load current that can be supported
is given by:
I
V
V
Amps
O MAX
IN
O
(
)
=
0 3
.
Where
is the efficiency (see Typical Performance Char-
acteristics).
The "burst" frequency (how often the LTC3525 delivers a
burst of current pulses to the load) is determined by the
internal hysteresis (output voltage ripple), the load current
and the amount of output capacitance. All Burst Mode
operation or hysteretic converters will enter the audible
frequency range when the load is light enough. However,
due to the low peak inductor current at light load, circuits
using the LTC3525 do not typically generate any audible
noise.
Figure 1. Inductor Current Changing as a Function of Load
OPERATIO
U
3525 F01
INDUCTOR
CURRENT
100mA/DIV
LOAD
CURRENT
50mA/DIV
10
s/DIV
10
LTC3525-3.3/LTC3525-5
3525f
Component Selection
Inductor values between 4.7
H and 15H are recom-
mended. In most applications 10
H will yield the best
compromise between size and efficiency. The inductor
should be a low-loss ferrite design and must be rated for
peak currents of at least 400mA without saturating. Induc-
tors with lower DC resistance will improve efficiency. Note
that the inductor value does not have a significant effect on
ripple current, so while lower values will increase the
operating frequency, they do not reduce output voltage
ripple.
Some recommended inductor examples are Murata
LQH32C and Coilcraft LPO4812, LPO3310, DO3314,
DS1608 and MSS4020.
A ceramic input bypass capacitor should be located as
close as possible to the V
IN
and GND pins of the IC. A
minimum value of 1
F is recommended. If the battery is
more than a few inches away, a bulk tantalum decoupling
cap of at least 10
F is recommended on V
IN
.
The output capacitor should also be a ceramic, located
close to the V
OUT
and GND pins. A minimum value of 10
F
is recommended. Increasing the value of the output ca-
pacitor to 22
F will result in lower output ripple. Higher
capacitor values will only offer a small reduction in output
ripple, while reducing light load efficiency by causing the
peak inductor current to increase above its minimum value
of 150mA. The input and output capacitors should be X5R
or X7R types, not Y5V.
SUPPLIER
PHONE
FAX
WEBSITE
Murata
USA: (814) 237-1431
USA: (814) 238-0490
www.murata.com
Coilcraft
(847) 639-6400
(847) 639-1469
www.coilcraft.com
Sumida
USA (847) 956-0666
USA (847) 956-0702
www.sumida.com
Table 1. Inductor Vendor Information
Table 2. Capacitor Vendor Information
SUPPLIER
PHONE
FAX
WEBSITE
Murata
USA: (814) 237-1431
USA: (814) 238-0490
www.murata.com
Taiyo Yuden
(408) 573-4150
(408) 573-4159
www.t-yuden.com
TDK
(847) 803-6100
(847) 803-6296
www.component.tdk.com
AVX
(803) 448-9411
(803) 448-1943
www.avxcorp.com
Figure 2. Recommended Component Placement
OPERATIO
U
SHDN
GND
V
IN
SW
GND
V
OUT
LTC3525
SHDN
V
IN
3525 F02
V
OUT
11
LTC3525-3.3/LTC3525-5
3525f
U
PACKAGE DESCRIPTIO
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.
SC6 Package
6-Lead Plastic SC70
(Reference LTC DWG # 05-08-1638)
1.15 1.35
(NOTE 4)
1.80 2.40
0.15 0.30
6 PLCS (NOTE 3)
0.10 0.18
(NOTE 3)
SC6 SC70 0802
1.80 2.20
(NOTE 4)
0.65 BSC
PIN 1
0.80 1.00
1.00 MAX
0.00 0.10
REF
0.10 0.40
0.10 0.30
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. DETAILS OF THE PIN 1 INDENTIFIER ARE OPTIONAL,
BUT MUST BE LOCATED WITHIN THE INDEX AREA
7. EIAJ PACKAGE REFERENCE IS EIAJ SC-70
3.26 MAX
0.47
MAX
0.65
REF
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
0.96 MIN
2.1 REF
1.16 REF
INDEX AREA
(NOTE 6)
Single Alkaline or NiMH to 3.3V Converter with 1mm Profile
2-Alkaline or NiMH to 3.3V
Li-Ion to 5V
6.8
H*
3525 TA05
LTC3525-3.3
*COILCRAFT LPO3310-682MXD
**MURATA GRM219R60J106KE191D
V
OUT
3.3V
60mA
4
1
2
5
6
3
V
OUT
GND
SW
SHDN
GND
V
IN
1V to 1.6V
10
F**
6.3V
1
F
10
H*
3525 TA06
LTC3525-3.3
*MURATA LQH32CN1002K53
V
OUT
3.3V
140mA
4
1
2
5
6
3
V
OUT
GND
SW
SHDN
GND
V
IN
1.8V to 3.2V
10
F
1
F
10
H*
3525 TA07
LTC3525-5
*COILCRAFT MSS4020-103MXD
V
OUT
5V
175mA
4
1
2
Li-ion
5
6
3
V
OUT
GND
SW
SHDN
GND
V
IN
3V to 4.2V
10
F
1
F
OFF ON
TYPICAL APPLICATIO S
U
12
LTC3525-3.3/LTC3525-5
3525f
LINEAR TECHNOLOGY CORPORATION 2005
LT/TP 0805 500 PRINTED IN THE USA
RELATED PARTS
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
FAX: (408) 434-0507
www.linear.com
PART NUMBER
DESCRIPTION
COMMENTS
LT
1615/LT1615-1
300mA/80mA (I
SW
), High Efficiency Step-Up DC/DC Converter
V
IN
: 1V to 15V, V
OUT(MAX)
= 34V, I
Q
= 20
A,
I
SD
<1
A, ThinSOT Package
LTC1751-3.3/
100mA, 800kHz, Micropower, Regulated Charge Pump
V
IN
: 2.5V to 5.5V, V
OUT(MAX)
= 3.3V/5V, I
Q
= 20
A,
LTC1751-5
DC/DC Converters
I
SD
<1
A, MS8 Package
LT1930/LTC1930A
1A (I
SW
), 1.2MHz/2MHz, High Efficiency Step-Up DC/DC Converter
High Efficiency, V
IN
: 2.6V to 16V, V
OUT(MAX)
= 34V,
I
Q
= 4.2mA/5.5mA, I
SD
<1
A, ThinSOT Package
LTC3200-5
100mA, 2MHz, Regulated 5V Charge Pump
V
IN
: 2.7V to 4.5V, V
OUT(MAX)
= 5V, I
Q
= 2mA,
I
SD
<1
A, ThinSOT Package
LTC3400/LTC3400B
600mA (I
SW
), 1.2MHz, Synchronous Step-Up DC/DC Converter
92% Efficiency, V
IN
: 0.5V to 5V, V
OUT(MAX)
= 5V,
I
Q
= 19
A/300A, I
SD
<1
A, ThinSOT Package
LTC3401
1A (I
SW
), 3MHz, Synchronous Step-Up DC/DC Converter
97% Efficiency, V
IN
: 0.5V to 5V, V
OUT(MAX)
= 5.5V,
I
Q
= 38
A, I
SD
<1
A, MS Package
LTC3402
2A (I
SW
), 3MHz, Synchronous Step-Up DC/DC Converter
97% Efficiency, V
IN
: 0.5V to 5V, V
OUT(MAX)
= 5.5V,
I
Q
= 38
A, I
SD
<1
A, MS Package
LTC3421
3A (I
SW
), 3MHz, Synchronous Step-Up DC/DC Converter
95% Efficiency, V
IN
: 0.5V to 4.5V, V
OUT(MAX)
= 5.25V,
with Output Disconnect
I
Q
= 12
A, I
SD
<1
A, QFN-24 Package
LTC3425
5A (I
SW
), 8MHz, 4-Phase Synchronous Step-Up DC/DC Converter
95% Efficiency, V
IN
: 0.5V to 4.5V, V
OUT(MAX)
= 5.25V,
with Output Disconnect
I
Q
= 12
A, I
SD
<1
A, QFN-32 Package
LTC3429/LTC3429B
600mA, 500kHz Single/Dual Cell Micropower Synchronous
95% Efficiency, V
IN
: 1V to 4.5V, V
OUT(MAX)
= 5V,
Boost Converter with Output Disconnect
I
Q
= 20
A, I
SD
<1
A, SC-70 Package
LTC3458
1.4A (I
SW
), 1.5MHz, Synchronous Step-Up DC/DC Converter
V
IN
: 1.5V to 6V, V
OUT(MAX)
= 7.5V, I
SD
<1
A,
with Output Disconnect
3mm
4mm DFN Package
LTC3458L
1.7A (I
SW
), 1.5MHz, Synchronous Step-Up DC/DC Converter
V
IN
: 1.5V to 6V, V
OUT(MAX)
= 6V, I
SD
<1
A,
with Output Disconnect
3mm
4mm DFN Package
LTC3459
60mA, 10V Micro Power Synchronous Boost Converter
95% Efficiency, V
IN
: 1.5V to 6V, V
OUT(MAX)
= 10V, I
Q
=10
A,
I
SD
<1
A, ThinSOT Package
LT3464
85mA (I
SW
), High Efficiency Step-Up DC/DC Converter
V
IN
: 2.3V to 10V, V
OUT(MAX)
= 34V, I
Q
= 25
A,
with Integrated Schottky and PNP Disconnect
I
SD
<1
A, ThinSOT Package
3.3V TO 5V Converter with 1.4mm Profile
10
H*
3525 TA08
LTC3525-5
*COILCRAFT DO3314-103MXD
**MURATA GRM21BR60J226ME39L
V
OUT
5V
200mA
4
1
2
5
6
3
V
OUT
GND
SW
SHDN
GND
V
IN
3.3V
22
F
**
6.3V
1
F
U
TYPICAL APPLICATIO
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