LINER LTC3525-5

LTC3525-3.3/LTC3525-5
400mA Micropower
Synchronous Step-Up DC/DC
Converter with Output Disconnect
U
FEATURES
DESCRIPTIO
■
The LTC®3525-3.3/LTC3525-5 are high efficiency synchronous step-up DC/DC converters with output disconnect 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.
■
■
■
■
■
■
■
■
■
■
■
■
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: IQ = 7µA
Only Three External Components
1V to 4.5V Input Range
<1µA Shutdown Current
Antiringing Control
Short-Circuit and Overtemperature Protection
Very low profile of 1mm
Tiny 6-Pin SC-70 Package
The device includes a 0.5Ω N-channel MOSFET switch and
a 0.8Ω P-channel synchronous rectifier. Peak switch
current ranges from 150mA to 400mA, depending on load,
providing enhanced efficiency. Quiescent current is an
ultralow 7µA, maximizing battery life in portable applications.
Other features include <1µA shutdown current, antiringing control and thermal shutdown. The LTC3525 is
available in a tiny 6-pin SC-70 package.
U
APPLICATIO S
■
■
■
■
MP3 Players
Portable Instruments
Glucose Meters
Digital Cameras
, 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
U
TYPICAL APPLICATIO
LTC3525-3.3 Efficiency and Power
Loss vs Load Current
L1*
10µH
100
100
90
LTC3525-3.3
VOUT
3.3V
60mA
1V to 1.6V
OFF ON
10
80
SW
SHDN
VOUT
GND
GND
10µF
1µF
EFFICIENCY (%)
VIN
EFFICIENCY
70
1
60
POWER LOSS
50
0.1
40
3525 TA01
*MURATA LQH32CN100K53
VIN = 3V
VIN = 2.4V
VIN = 1.2V
30
20
0.01
POWER LOSS (mW)
VIN
0.1
1
10
LOAD (mA)
100
0.01
1000
LT3525 • TA02
3525f
1
LTC3525-3.3/LTC3525-5
W W
W
AXI U
U
ABSOLUTE
RATI GS
U
U
W
PACKAGE/ORDER I FOR ATIO
(Note 1)
VIN, VOUT 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 85°C
Storage Temperature Range ................ – 65°C to 125°C
Lead Temperature (Soldering, 10 sec)................. 300°C
TOP VIEW
SHDN 1
6 SW
GND 2
5 GND
VIN 3
4 VOUT
SC6 PACKAGE
6-LEAD PLASTIC SC70
TJMAX = 125°C
θJA = 256°C/ W IN FREE AIR, θJA = 150°C/ W ON BOARD
OVER GROUND PLANE
ORDER PART NUMBER
SC6 PART MARKING
LTC3525ESC6-3.3
LTC3525ESC6-5
LBTG
LBWT
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/
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
(LTC3525-3.3)
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VIN = 1.2V, VSHDN = 1.2V, VOUT = 3.3V unless otherwise noted.
PARAMETER
CONDITIONS
MIN
Input Start-Up Voltage
●
3.20
TYP
MAX
0.85
1
UNITS
V
Output Voltage
(Note 6)
3.30
3.40
V
Quiescent Current, VOUT
SHDN = VIN (Note 4)
7
15
µA
Quiescent Current, VIN
SHDN = VIN (Note 4)
0.5
3
µA
Quiescent Current, VIN - Shutdown
SHDN = 0V, VOUT = 0V
Not Including Switch Leakage
0.1
1
µA
NMOS Switch Leakage
VIN = VOUT = VSW = 5V, SHDN = 0V
0.1
1
µA
PMOS Switch Leakage
VIN = VSW = 5V, VOUT = 0V, SHDN = 0V
0.1
3
µA
NMOS Switch On Resistance
PMOS Switch On Resistance
0.5
Ω
0.8
Ω
Peak Current Limit
0.4
0.45
SHDN Threshold
0.4
0.6
1
V
0.01
1
µA
SHDN Input Current
VSHDN = VIN or VOUT
A
3525f
2
LTC3525-3.3/LTC3525-5
ELECTRICAL CHARACTERISTICS
(LTC3525-5)
The ● denotes specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
VIN = 2.4V, VSHDN = 2.4V, VOUT = 5V unless otherwise noted.
PARAMETER
CONDITIONS
MIN
Input Start-Up Voltage
●
4.85
TYP
MAX
0.85
1
UNITS
V
Output Voltage
(Note 6)
5.00
5.15
V
Quiescent Current, VOUT
SHDN = VIN
8
18
µA
Quiescent Current, VIN
SHDN = VIN
1.5
5
µA
Quiescent Current, VIN - Shutdown
SHDN = 0V, VOUT = 0V
Not Including Switch Leakage
0.1
1
µA
NMOS Switch Leakage
VIN = VOUT = VSW = 5V, SHDN = 0V
0.1
1
µA
PMOS Switch Leakage
VIN = VSW = 5V, VOUT = 0V, SHDN = 0V
0.1
3
µA
NMOS Switch On Resistance
0.4
Ω
PMOS Switch On Resistance
0.7
Ω
Peak Current Limit
0.4
0.5
SHDN Threshold
0.4
0.6
1
V
0.01
1
µA
SHDN Input Current
VSHDN = VIN or VOUT
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 70°C. Specifications over the –40°C to 85°C 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.
A
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.
3525f
3
LTC3525-3.3/LTC3525-5
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Maximum Output Current vs VIN
(for VOUT to Drop 2.5%)
TA = 25°C unless otherwise noted.
Maximum Startup Load vs VIN
(Resitive Load)
350
No-Load Input Current vs VIN
50
250
300
45
LTC3525-5
40
200
200
LTC3525-5
150
150
IIN (µA)
35
LTC3525-3.3
LOAD (mA)
IOUT (mA)
250
LTC3525-3.3
100
50
20
LTC3525-3.3
5
0
0.5
1.0
1.5
2.0
2.5 3.0
VIN (V)
3.5
4.0
0.5
1.5
2.0
VIN (V)
1.0
3.0
2.5
100
20
0.01
1
10
LOAD (mA)
0.1
50
POWER LOSS
40
0
0.01
0.1
1
10
LOAD (mA)
VIN = 2.4V
–0.5
COUT = 10µF
–1.0
–1.0
–2.5
1.0
0.5
COUT = 22µF
0
COUT = 10µF
–0.5
–1.0
–2.5
80
0
10
20
30
40
LOAD (mA)
50
60
3525 G08
COUT = 22µF
0
–0.5
–1.0
–2.0
3525 G07
70
0.5
–2.0
80 100 120 140 160 180
LOAD (mA)
60
1.0
–2.0
60
30 40 50
LOAD (mA)
1.5
–1.5
40
20
VIN = 2.4V
2.0
–1.5
20
10
LTC3525-5 Load Regulation
2.5
–1.5
0
0
3525 G06
CHANGE IN VOUT (%)
COUT = 22µF
0
COUT = 10µF
–0.5
–2.0
1.5
CHANGE IN VOUT (%)
1.5
1.0
COUT = 22µF
0
–1.5
VIN = 1.2V
2.0
0.5
0.5
LTC3525-5 Load Regulation
2.5
4.5
1.0
3525 G05
LTC3525-3.3 Load Regulation
2.0
1
VIN = 3.6V 0.1
VIN = 2.4V
VIN = 1.2V
0.01
100
1000
3525 G04
2.5
4.0
1.5
CHANGE IN VOUT (%)
EFFICIENCY (%)
10
10
0.01
1000
100
60
20
VIN = 3V
VIN = 2.4V
VIN = 1.2V
30
EFFICIENCY
30
0.1
40
100
70
POWER LOSS (mW)
POWER LOSS
50
POWER LOSS (mW)
1
60
3.5
VIN = 1.2V
2.0
80
10
EFFICIENCY
2.5 3.0
VIN (V)
LTC3525-3.3 Load Regulation
2.5
1000
90
90
70
2.0
3525 G03
LTC3525-5 Efficiency and Power
Loss vs Load
100
80
1.5
3525 G02
LTC3525-3.3 Efficiency and Power
Loss vs Load
100
0
1.0
0
4.5
3525 G01
–2.5
LTC3525-5
10
50
EFFICIENCY (%)
25
15
100
CHANGE IN VOUT (%)
30
–2.5
COUT = 10µF
0
20
40
60
80 100
LOAD (mA)
120
140
3525 G09
3525f
4
LTC3525-3.3/LTC3525-5
U W
TYPICAL PERFOR A CE CHARACTERISTICS
LTC3525-5 Load Regulation
2.5
1200
0.5
COUT = 22µF
0
COUT = 10µF
–0.5
–1.0
900
800
700
500
–2.0
400
50
100
LOAD (mA)
150
LTC3525-3.3
600
–1.5
0
30
25
20
COUT = 10µF
15
10
COUT = 22µF
5
300
1.0
200
BURST FREQUENCY (kHz)
1.0
1.5
2.0
2.5 3.0
VIN (V)
3.5
4.0
3525 G10
4.5
0
0.1
1
LOAD (mA)
3525 G11
VOUT Variation vs Temperature
(Normalized to 25°C)
LTC3525-3.3 Input Current and
VOUT at Startup
120
0.3
10
3525 G12
Startup Delay Coming Out of
Shutdown
0.4
VIN = 1.2V
100
0.2
SWITCHING DELAY (µs)
CHANGE IN VOUT (%)
35
LTC3525-5
1000
FREQUENCY (kHz)
CHANGE IN VOUT (%)
40
L = 10µH
1100
1.5
–2.5
Light Load Burst Frequency
vs Load
Switching Frequency vs VIN
VIN = 3.6V
2.0
TA = 25°C unless otherwise noted.
0.1
0
–0.1
–0.2
VOUT
1V/DIV
80
60
INPUT
CURRENT
100mA/DIV
40
500µs/DIV
3525 G15
20
–0.3
–0.4
–40–30–20–10 0 10 20 30 40 50 60 70 80
TEMPERATURE (°C)
0
1.0
1.5
2.0
2.5 3.0
VIN (V)
3.5
3525 G13
4.0
4.5
3525 G14
LTC3525-3.3 Output Voltage
Ripple
LTC3525-3.3 Output Voltage
Ripple
IOUT =
5mA
IOUT =
5mA
IOUT =
40mA
50mV/DIV
IOUT =
80mA
IOUT =
40mA
50mV/DIV
IOUT =
80mA
VIN = 1.2V
COUT = 10µF
50µs/DIV
3525 G16
VIN = 1.2V
COUT = 22µF
50µs/DIV
3525 G17
3525f
5
LTC3525-3.3/LTC3525-5
U W
TYPICAL PERFOR A CE CHARACTERISTICS
LTC3525-3.3 Output Voltage
Ripple
TA = 25°C unless otherwise noted.
LTC3525-5 Output Voltage Ripple
IOUT =
5mA
IOUT =
5mA
IOUT =
100mA
50mV/DIV
IOUT =
190mA
IOUT =
50mA
50mV/DIV
IOUT =
150mA
VIN = 2.4V
COUT = 22µF
50µs/DIV
3525 G18
VIN = 2.4V
COUT = 22µF
50µs/DIV
3525 G19
LTC3525-3.3 50mA Load Step
Response
LTC3525-5 Output Voltage Ripple
IOUT =
20mA
IOUT =
100mA
50mV/DIV
OUTPUT
RIPPLE
50mV/DIV
LOAD
CURRENT
20mA/DIV
IOUT =
200mA
VIN = 3.6V
COUT = 22µF
50µs/DIV
3525 G20
VIN = 1.2V
COUT = 22µF
LTC3525-3.3 100mA Load Step
Response
500µs/DIV
3525 G21
LTC3525-5 100mA Load Step
Response
OUTPUT
RIPPLE
50mV/DIV
OUTPUT
RIPPLE
50mV/DIV
LOAD
CURRENT
50mA/DIV
LOAD
CURRENT
50mA/DIV
VIN = 2.4V
COUT = 22µF
500µs/DIV
3525 G22
VIN = 3.6V
COUT = 22µF
500µs/DIV
3525 G23
3525f
6
LTC3525-3.3/LTC3525-5
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.
VOUT (Pin 4): Output Voltage Sense and the Output of the
Synchronous Rectifier. Connect the output filter capacitor
from VOUT to GND, close to the IC. A minimum value of
10µF ceramic is recommended. Use 22µF for reduced
output ripple. The output disconnect feature disconnects
VOUT from VIN when SHDN is <0.4V.
GND (Pins 2, 5): Ground.
VIN (Pin 3): Input Voltage. The LTC3525 is powered from
VIN until VOUT exceeds VIN. Once VOUT is greater than (VIN
+ 0.2V typical), it is powered from VOUT. Place a ceramic
bypass capacitor from VIN to GND. A minimum value of
1µF is recommended.
SW (Pin 6): Switch Pin. Connect an inductor from this pin
to VIN. An internal antiringing resistor is connected across
SW and VIN after the inductor current has dropped to zero
to minimize EMI.
W
BLOCK DIAGRA
SW
VIN
6
3
VOUT
VSEL
VBEST
WELL
SWITCH
VB
4 VOUT
SHUTDOWN
SHUTDOWN GATE DRIVERS
AND
ANTI-CROSS
CONDUCTION
+
–
OFFSET
VREF
UVLO
ADJUST
VREF
IPK
UVLO
–
+
+
STARTUP
LOGIC
IPK
COMPARATOR
IVAL
–
ADJUST
+
SHUTDOWN
IVALLEY
COMPARATOR
WAKE
+
TSD
–
THERMAL
SHUTDOWN
OFFSET
–
SHDN 1
INTEGRATOR
FB
VREF
SLEEP
COMPARATOR
ADJUST
2
3525 BD
GND
3525f
7
LTC3525-3.3/LTC3525-5
U
OPERATIO
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, VIN 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 operation while eliminating the need for an external Schottky
diode. True output disconnect eliminates inrush current at
start-up, and allows VOUT to be disconnected from VIN, for
zero shutdown current.
The output disconnect feature also allows the LTC3525 to
maintain regulation with an input voltage equal to or
greater than VOUT. 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 7µA typical, allowing 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 VIN or VOUT, the SHDN input current
will increase from zero to 1.5µA.
After the SHDN pin rises, there is a short delay before
switching starts. The delay is 20µs to 120µs, 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. VOUT must exceed VIN by at least
0.2V typical and either VIN or VOUT 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 (VIN +
1V) typical. This limits inrush current by maintaining
control of the inductor current when VOUT is less than VIN.
To reduce power dissipation in the P-channel synchronous rectifier when the output is shorted, a foldback
feature is incorporated that reduces the peak inductor
current when VIN is more than 1.7V greater than VOUT.
Normal Operation
Once VOUT has increased more than 0.2V typical above
VIN, 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 regulation 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
3525f
8
LTC3525-3.3/LTC3525-5
U
OPERATIO
INDUCTOR
CURRENT
100mA/DIV
LOAD
CURRENT
50mA/DIV
10µs/DIV
3525 F01
Figure 1. Inductor Current Changing as a Function of Load
load using the minimum recommended 10µF output capacitor for the LTC3525-3.3 and a 22µF 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 inductor 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 47µF will result in higher peak currents than necessary 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:
IO(MAX) =
0.3 • VIN • η
Amps
VO
Where η is the efficiency (see Typical Performance Characteristics).
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.
3525f
9
LTC3525-3.3/LTC3525-5
U
OPERATIO
Component Selection
A ceramic input bypass capacitor should be located as
close as possible to the VIN and GND pins of the IC. A
minimum value of 1µF is recommended. If the battery is
more than a few inches away, a bulk tantalum decoupling
cap of at least 10µF is recommended on VIN.
Inductor values between 4.7µH and 15µH are recommended. In most applications 10µH 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. Inductors 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.
The output capacitor should also be a ceramic, located
close to the VOUT and GND pins. A minimum value of 10µF
is recommended. Increasing the value of the output capacitor to 22µF 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.
Some recommended inductor examples are Murata
LQH32C and Coilcraft LPO4812, LPO3310, DO3314,
DS1608 and MSS4020.
Table 1. Inductor Vendor Information
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 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
SHDN
SHDN
SW
LTC3525
VIN
GND
GND
VIN
VOUT
VOUT
3525 F02
Figure 2. Recommended Component Placement
3525f
10
LTC3525-3.3/LTC3525-5
U
TYPICAL APPLICATIO S
Single Alkaline or NiMH to 3.3V Converter with 1mm Profile
2-Alkaline or NiMH to 3.3V
10µH*
6.8µH*
1V to 1.6V
3
1
2
LTC3525-3.3
SW
VIN
SHDN
VOUT
GND
GND
1.8V to 3.2V
6
3
VOUT
3.3V
60mA
4
5
1
2
10µF**
6.3V
1µF
LTC3525-3.3
VIN
SW
SHDN
VOUT
GND
GND
6
VOUT
3.3V
140mA
4
5
10µF
1µF
3525 TA06
3525 TA05
*MURATA LQH32CN1002K53
*COILCRAFT LPO3310-682MXD
**MURATA GRM219R60J106KE191D
Li-Ion to 5V
10µH*
3V to 4.2V
3
OFF ON
Li-ion
1
2
LTC3525-5
VIN
SW
SHDN
VOUT
GND
GND
6
VOUT
5V
175mA
4
5
1µF
10µF
3525 TA07
*COILCRAFT MSS4020-103MXD
U
PACKAGE DESCRIPTIO
SC6 Package
6-Lead Plastic SC70
(Reference LTC DWG # 05-08-1638)
0.10 – 0.40
0.47
MAX
0.65
REF
1.80 – 2.20
(NOTE 4)
1.16 REF
0.10 – 0.30
0.10 – 0.18
(NOTE 3)
3.26 MAX 2.1 REF
0.96 MIN
INDEX AREA
(NOTE 6)
1.80 – 2.40 1.15 – 1.35
(NOTE 4)
0.80 – 1.00
0.00 – 0.10
REF
1.00 MAX
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
PIN 1
0.65 BSC
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
0.15 – 0.30
6 PLCS (NOTE 3)
SC6 SC70 0802
3525f
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
LTC3525-3.3/LTC3525-5
U
TYPICAL APPLICATIO
3.3V TO 5V Converter with 1.4mm Profile
10µH*
3
3.3V
1
2
LTC3525-5
VIN
SW
SHDN
VOUT
GND
GND
6
VOUT
5V
200mA
4
5
22µF**
6.3V
1µF
3525 TA08
*COILCRAFT DO3314-103MXD
**MURATA GRM21BR60J226ME39L
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT 1615/LT1615-1
300mA/80mA (ISW), High Efficiency Step-Up DC/DC Converter
VIN: 1V to 15V, VOUT(MAX) = 34V, IQ = 20µA,
ISD <1µA, ThinSOT Package
LTC1751-3.3/
LTC1751-5
100mA, 800kHz, Micropower, Regulated Charge Pump
DC/DC Converters
VIN: 2.5V to 5.5V, VOUT(MAX) = 3.3V/5V, IQ = 20µA,
ISD <1µA, MS8 Package
LT1930/LTC1930A
1A (ISW), 1.2MHz/2MHz, High Efficiency Step-Up DC/DC Converter
High Efficiency, VIN: 2.6V to 16V, VOUT(MAX) = 34V,
IQ = 4.2mA/5.5mA, ISD <1µA, ThinSOT Package
LTC3200-5
100mA, 2MHz, Regulated 5V Charge Pump
VIN: 2.7V to 4.5V, VOUT(MAX) = 5V, IQ = 2mA,
ISD <1µA, ThinSOT Package
LTC3400/LTC3400B
600mA (ISW), 1.2MHz, Synchronous Step-Up DC/DC Converter
92% Efficiency, VIN: 0.5V to 5V, VOUT(MAX) = 5V,
IQ = 19µA/300µA, ISD <1µA, ThinSOT Package
LTC3401
1A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter
97% Efficiency, VIN: 0.5V to 5V, VOUT(MAX) = 5.5V,
IQ = 38µA, ISD <1µA, MS Package
LTC3402
2A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter
97% Efficiency, VIN: 0.5V to 5V, VOUT(MAX) = 5.5V,
IQ = 38µA, ISD <1µA, MS Package
LTC3421
3A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter
with Output Disconnect
95% Efficiency, VIN: 0.5V to 4.5V, VOUT(MAX) = 5.25V,
IQ = 12µA, ISD <1µA, QFN-24 Package
LTC3425
5A (ISW), 8MHz, 4-Phase Synchronous Step-Up DC/DC Converter
with Output Disconnect
95% Efficiency, VIN: 0.5V to 4.5V, VOUT(MAX) = 5.25V,
IQ = 12µA, ISD <1µA, QFN-32 Package
LTC3429/LTC3429B
600mA, 500kHz Single/Dual Cell Micropower Synchronous
Boost Converter with Output Disconnect
95% Efficiency, VIN: 1V to 4.5V, VOUT(MAX) = 5V,
IQ = 20µA, ISD <1µA, SC-70 Package
LTC3458
1.4A (ISW), 1.5MHz, Synchronous Step-Up DC/DC Converter
with Output Disconnect
VIN: 1.5V to 6V, VOUT(MAX) = 7.5V, ISD <1µA,
3mm × 4mm DFN Package
LTC3458L
1.7A (ISW), 1.5MHz, Synchronous Step-Up DC/DC Converter
with Output Disconnect
VIN: 1.5V to 6V, VOUT(MAX) = 6V, ISD <1µA,
3mm × 4mm DFN Package
LTC3459
60mA, 10V Micro Power Synchronous Boost Converter
95% Efficiency, VIN: 1.5V to 6V, VOUT(MAX) = 10V, IQ =10µA,
ISD <1µA, ThinSOT Package
LT3464
85mA (ISW), High Efficiency Step-Up DC/DC Converter
with Integrated Schottky and PNP Disconnect
VIN: 2.3V to 10V, VOUT(MAX) = 34V, IQ = 25µA,
ISD <1µA, ThinSOT Package
®
3525f
12
Linear Technology Corporation
LT/TP 0805 500 • PRINTED IN THE USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2005