LINER LTC3459 10v micropower synchronous boost converter Datasheet

LTC3459
10V Micropower
Synchronous Boost Converter
FEATURES
DESCRIPTION
n
The LTC®3459 is a low current, high efficiency synchronous
boost converter intended for low power, size constrained
portable applications. The LTC3459 can be powered from
a single lithium ion battery, a 2- to 3-cell stack of alkaline
or nickel batteries, or any low impedance voltage source
between 1.5V and 5.5V. The output is programmable via
an external divider between 2.5V and 10V. Although the
part is primarily intended for boost applications, VOUT will
maintain regulation below VIN (at reduced efficiency).
n
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Small Solution Size
>85% Efficiency over Wide Load Range
Internal Synchronous Rectifier
VIN Range: 1.5V to 5.5V
5V at 30mA from 3.3V Input
3.3V at 20mA from 2 AA Cell Input
Programmable Output Voltages Up to 10V
Burst Mode® Operation
Inrush Current Limiting
Output Disconnect in Shutdown
Ultralow Quiescent (10μA) and Shutdown (<1μA)
Currents
Low Profile 2mm × 2mm DFN, 2mm × 3mm DFN or
SOT-23 Package
APPLICATIONS
n
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The LTC3459 offers Burst Mode operation with a fixed
peak current, providing high conversion efficiency over
a wide range of load currents. During start-up, inductor
current is controlled preventing the inrush surge current
found in many boost converters. In shutdown the output
is disconnected from the input and quiescent current is
reduced to <1μA.
The LTC3459 is offered in low profile 6-pin 2mm × 2mm
DFN, 2mm × 3mm DFN or SOT-23 (ThinSOT TM) packages,
allowing a tiny footprint for the total solution.
General Purpose Micropower Boost
Digital Cameras
PDAs
LCD Bias
Small OLED Displays
Supercap Charging
, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology
Corporation. ThinSOT is a trademark of Linear Technology Corporation. All other
trademarks are the property of their respective owners.
TYPICAL APPLICATION
5V to 8V Converter
Efficiency
100
22μH
VIN = 5V
VOUT = 8V
5V
VIN
2M
LTC3459
1μF
OFF ON
VOUT
8V
30mA
VOUT
SHDN
GND
FB
47pF
4.7μF
EFFICIENCY (%)
90
SW
80
70
365k
3459 TA01a
60
50
0.01
0.1
1
ILOAD (mA)
10
100
3459 TA01b
3459fc
1
LTC3459
ABSOLUTE MAXIMUM RATINGS
Referred to GND (Note 1)
VIN, FB Voltage ........................................... –0.3V to 7V
VOUT, SHDN Voltage ................................. –0.3V to 10V
SW Voltage .............................................. –0.3V to 12V
Operating Temperature Range
(Notes 2, 3) ......................................... –40°C to 85°C
Storage Temperature Range.................. –65°C to 150°C
Reflow Temperature .............................................. 260°C
Lead Temperature, S6 Package
(Soldering, 10 sec) .......................................... 300°C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
TOP VIEW
VIN 1
VOUT 2
SHDN 3
7
6 SW
SHDN 1
5 GND
VOUT 2
4 FB
DC PACKAGE
6-LEAD (2mm s 2mm) PLASTIC DFN
TJMAX = 125°C, θJA = 102°C/W
EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB
6 VIN
7
FB 3
5 GND
4 SW
DCB PACKAGE
6-LEAD (2mm × 3mm) PLASTIC DFN
TJMAX = 125°C, θJA = 64°C/W
EXPOSED PAD (PIN 7) IS GND, MUST BE SOLDERED TO PCB
SW 1
GND 2
FB 3
6 VIN
5 VOUT
4 SHDN
S6 PACKAGE
6-LEAD PLASTIC TSOT-23
TJMAX = 125°C, θJA = 192°C/W
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING
PACKAGE DESCRIPTION
TEMPERATURE RANGE
LTC3459EDC#PBF
LTC3459EDC#TRPBF
LDTG
Low Profile (2mm × 2mm) Plastic DFN
–40°C to 85°C
LTC3459EDCB#PBF
LTC3459EDCB#TRPBF
LDMM
Low Profile (2mm × 3mm) Plastic DFN
–40°C to 85°C
LTC3459ES6#PBF
LTC3459ES6#TRPBF
LTAHA
Low Profile SOT-23
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges.
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/
3459fc
2
LTC3459
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. VIN = 3.3V, VOUT = 5V, unless otherwise noted.
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
VIN
l
Input Voltage Range
1.5
5.5
V
VIN Quiescent Current
SHDN = VCC
10
20
μA
VIN Shutdown Current
SHDN = GND
0.1
1
μA
VOUT
l
Programmable Voltage Range
10
V
VOUT Quiescent Supply Current
SHDN = VCC
2.5
2
4
μA
VOUT Shutdown Current
SHDN = GND
0.1
1
μA
1.22
1.25
V
10
50
nA
60
75
90
mA
225
400
550
ns
Reference
Feedback Voltage
VIN = 3.3V, VOUT = 7.5V
FB Input Leakage Current
Measured on FB
l
1.19
Converter Performance
l
Peak Switch Current (VIN = 3.3V)
L = 22μH
tOFF Timer (VIN = 3.3V, VOUT = 5V)
Varies by 1/(VOUT – VIN)
Zero Current Comparator Threshold
L = 22μH
0
mA
On-Resistance
VOUT = 5V
2.8
Ω
Leakage Current
VSWITCH = 10V, VOUT = 10V
0.01
On-Resistance
VOUT = 5V
4.2
Leakage Current
VIN = 5V, VSWITCH = 5V, VOUT = 0V
0.02
Main NMOS Switch
1
μA
Main PMOS Switch
Ω
2
μA
1
V
Logic Inputs
SHDN Threshold (Rising Edge)
0.3
SHDN Hysteresis
SHDN Input Leakage Current
80
SHDN = 3.3V
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
reliability and lifetime.
Note 2: The LTC3459E is guaranteed to meet performance specifications
from 0°C to 85°C. Specifications over the –40°C to 85°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
0
mV
50
nA
Note 3: 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.
3459fc
3
LTC3459
TYPICAL PERFORMANCE CHARACTERISTICS
Minimum ROUT vs VIN
2500
2000
1500
VIN = 3.3V
14 VOUT = 5V
VOUT = 10V
VOUT = 7.5V
VOUT = 5V
VOUT = 3.3V
L = 22μH
350
300
POUT (mW)
ROUT (Ω)
3000
16
400
VOUT = 10V
VOUT = 7.5V
VOUT = 5V
VOUT = 3.3V
L = 22μH
3500
VIN and VOUT Quiescent Current
vs Temperature
Maximum POUT vs VIN
12
CURRENT (μA)
4000
(TA = 25°C, unless otherwise noted).
250
200
150
IIN
10
8
6
1000
100
4
500
50
2
0
1.5
2
2.5
3.5
3
4
4.5
5
0
1.5
5.5
2
2.5
3
VIN (V)
3.5
4
4.5
1.5
2.0
1.5
1.0
0.5
80
N-Channel and P-Channel
MOSFET RDS(ON) vs Temperature
6
4.7μF
10μF
22μF
47μF
VOUT = 5V
L = 22μH
VOUT = 5V
5
PCH
4
RDS(ON) (Ω)
2.0
VOUT = 10V
VOUT = 7.5V
VOUT = 5V
VOUT = 3.3V
L = 22μH
60
0
40
20
TEMPERATURE (°C)
3459 G03
VOUT Regulation vs VIN and COUT
% CHANGE IN VOUT
FREQUENCY (MHz)
–20
3459 G02
Switching Frequency
vs VIN at Various VOUTs
2.5
0
–40
5.5
VIN (V)
3459 G01
3.0
5
IOUT
0
–0.5
NCH
3
2
–1.0
1.0
1
–1.5
0.5
1.5
2
2.5
3
3.5
4
4.5
5
5.5
–2.0
1.5
2
2.5
VIN (V)
3
3.5
4
4.5
5
5.5
0
–40
–20
VIN (V)
3459 G04
40
20
60
0
TEMPERATURE (°C)
3459 G06
3459 G05
Shutdown Threshold Voltage
vs Temperature
80
Burst Cycle
Switch Pin Waveform
SHUTDOWN THRESHOLD VOLTAGE (V)
1.2
1.0
SW
CURRENT
50mA/DIV
SHDN RISING
0.8
SW
CURRENT
50mA/DIV
SHDN FALLING
0.6
0.4
0.2
0
–40
INDUCTOR
CURRENT
50mA/DIV
INDUCTOR
CURRENT
50mA/DIV
VIN = 3.3V
VOUT = 5V
L = 22μH
–20
40
20
60
0
TEMPERATURE (°C)
1μs/DIV
3459 G08
VIN = 3.3V
VOUT = 5V
L = 22μH
100ns/DIV
3459 G09
80
3459 G07
3459fc
4
LTC3459
TYPICAL PERFORMANCE CHARACTERISTICS
VOUT AC Ripple
Burst Cycle
VOUT
50mV/DIV
INDUCTOR
CURRENT
50mA/DIV
VIN = 3.3V
VOUT = 5V
L = 22μH
COUT = 4.7μF
CFF = 47pF
(TA = 25°C, unless otherwise noted).
5μs/DIV
Burst Cycle
SW
CURRENT
50mA/DIV
SW
CURRENT
50mA/DIV
INDUCTOR
CURRENT
50mA/DIV
INDUCTOR
CURRENT
50mA/DIV
VIN = 5V
VOUT = 10V
L = 22μH
3459 G10
VOUT Regulated Below
VIN Burst Cycle
1μs/DIV
3459 G11
Shorted Output
SW
CURRENT
50mA/DIV
1μs/DIV
INPUT
CURRENT
50mA/DIV
VIN = 5V
VOUT = 0V
L = 22μH
3459 G13
3459 G12
VOUT
VOLTAGE
50mA/DIV
INDUCTOR
CURRENT
50mA/DIV
INDUCTOR
CURRENT
50mA/DIV
1μs/DIV
Start-Up
SW
CURRENT
50mA/DIV
VIN = 5V
VOUT = 3.5V
L = 22μH
VIN = 2V
VOUT = 10V
L = 22μH
500ns/DIV
Load Steps
3459 G14
250μs/DIV
VIN = 3.6V
VOUT = 0V TO 8V
L = 22μH
CIN = 2.2μF
3459 G15
Load Steps
VOUT
AC RIPPLE
50mV/DIV
WITH 50kΩ
(TRACE 2
GROUNDED)
TO 500Ω
(TRACE 2 = 5V)
VOUT
AC RIPPLE
50mV/DIV
WITH 5kΩ
(TRACE 2
GROUNDED)
TO 500Ω
(TRACE 2 = 5V)
VIN = 3.6V
VOUT = 8V
L = 22μH
COUT = 4.7μF
CFF = 47pF
100μs/DIV
3459 G16
VIN = 3.6V
VOUT = 8V
L = 22μH
COUT = 4.7μF
CFF = 47pF
100μs/DIV
3459 G17
3459fc
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LTC3459
PIN FUNCTIONS
(DC/DCB/S6 Packages)
GND (Pin 5/Pin 5/Pin 2): Signal and Power Ground. Provide
a short, direct PCB path between GND and the (–) side of
the filter capacitors on VIN and VOUT.
VIN (Pin 1/Pin 6/Pin 6): Input Supply Pin. Bypass VIN with
a low ESR, ESL ceramic capacitor of at least 1μF.
VOUT (Pin 2/Pin 2/Pin 5): Regulated Output Voltage of
the Boost Regulator. Bypass VOUT with a low ESR, ESL
ceramic capacitor between 2.2μF and 10μF. VOUT ripple
increases with smaller capacitors.
SW (Pin 6/Pin 4/Pin 1): Switch Pin. Connect a 15μH to
33μH inductor between SW and VIN. Keep PCB trace lengths
as short and wide as possible to reduce EMI and voltage
overshoot. If the inductor current falls to zero, the internal
P-channel MOSFET synchronous rectifier is turned off to
prevent reverse charging of the inductor.
SHDN (Pin 3/Pin 1/Pin 4): Master Shutdown Input. Driving
SHDN low disables all IC functions and reduces quiescent
current from the battery to less than 1μA. This pin must
be pulled above 1V to enable the IC.
Exposed Pad (Pin 7/Pin 7, DC and DCB Packages Only):
Ground. The Exposed Pad must be soldered to PCB.
FB (Pin 4/Pin 3/Pin 3): Input to the Burst Mode Comparator.
An external resistor divider connected between VOUT,
GND and this pin sets the output voltage to:
VOUT = 1.22(1 + R1/R2)
BLOCK DIAGRAM
VCC
SW
+
Q SD
IPEAK
IZO
QB R
Q
P/~N
IZERO
DETECT
VBEST SW1
S
VOUT
QB RD
IZO
S
VIN
–
tOFF
tOFF
TIMER
VOUT
VSELECT
VSELECT
Q
THERMAL
SD
SLEEP
DELAY
P-DRIVE
R1
RD QB
–
VBEST
R2
HYSTCOMP
IPEAK
DETECT
+
VCC
FB
VCC
N-DRIVE
REFOK
N-DRIVE
SDB
P-DRIVE
REFERENCE
SD
SD
SDB
GND
SHDN
3459 BD
OFF ON
3459fc
6
LTC3459
OPERATION
Operation
The LTC3459 synchronous boost converter utilizes a
Burst Mode control technique to achieve high efficiency
over a wide dynamic range. A 2.5% accurate comparator
is used to monitor the output voltage (VOUT), if VOUT is
above the comparator threshold, no switching occurs and
only quiescent current (10μA) is drawn from the power
source. When VOUT drops below the comparator threshold,
switching commences and the output capacitor is charged.
During the on time of the switching period, inductor current is ramped through an internal N-channel MOSFET to
GND until a peak current (75mA) is detected. A P-channel
MOSFET connects the inductor to VOUT during the off time
delivering energy to the load. The off time is controlled by
an internal timer which is proportional to 1/(VOUT – VIN).
Anticross conduction circuitry ensures the N- and P-channel switches are never on simultaneously.
Only three power components and two feedback resistors
are required to complete the design of the boost converter,
an external Schottky diode is not required. The high operating frequency allows the use of low value, low profile
inductors and tiny external ceramic capacitors. The boost
converter disconnects VOUT from VIN during shutdown to
avoid loading the input power source.
Peak Current Overshoot
The LTC3459’s peak current comparator has a delay of approximately 100ns from the time inductor current reaches
current limit until the internal N-channel MOSFET turns off.
This delay causes the peak current to overshoot based on
the inductor value and VIN, as follows (Figure 2 is based
on a 65mA initial ILIMIT).
V
IPEAK = ILIMIT + (100ns) IN
L
tOFF Timer
The LTC3459’s tOFF timer is designed to keep the inductor
current continuous during a Burst Mode switching packet,
thereby increasing current capability at the output. A larger
inductor value will have lower peak-to-peak current ripple,
increasing the available current to the load. This improvement is offset somewhat by the reduced IPEAK overshoot.
The tOFF timer is designed to maintain a relatively constant
peak-to-peak current in the inductor despite VIN changes.
~50mVP-P
VOUT
AC
RIPPLE
IPEAK
tOFF
N
P
tOFF
N
P
~100mA
tOFF
N
P
N
P
IZERO WAIT
BURST ON
N
SLEEP
tOFF
P
N
BURST ON
3459 F01
Figure 1. Inductor Current and VOUT Ripple Waveforms
0.8
110
0.7
100
0.6
15μH
0.5
22μH
tOFF (μs)
IPEAK (mA)
90
80
33μH
0.4
0.3
70
0.2
60
0.1
50
1.5
2
2.5
3
4
3.5
VIN (V)
4.5
5
5.5
3459 F02
Figure 2. Typical IPEAK Values
0
0.5 1.5
2.5
3.5 4.5 5.5
VOUT – VIN (V)
6.5
7.5
8.5
3459 F03
Figure 3. tOFF Times
3459fc
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LTC3459
OPERATION
This is accomplished by varying the tOFF period by approximately 1/(VOUT – VIN). Due to propagation delays
and a 0.6μA bias current in the timer, the tOFF time can be
more accurately predicted as follows:
tOFF ≈ 100ns +
0.8 pF • 1.25V
V
–V
0.6μA + OUT IN
500k
If VOUT is less than VIN, the tOFF delay is fixed at approximately 750ns.
APPLICATIONS INFORMATION
Inductor Selection
Capacitor Selection
An inductor with a minimum value of 15μH is recommended
for use with the LTC3459. Values larger than 15μH will
result in lower ripple current and switching frequency.
High frequency ferrite core materials are strongly recommended. Some inductors meeting these requirements are
listed in Table 1.
The boost converter requires two capacitors. The input
capacitor should be an X5R type of at least 1.0μF. The VOUT
capacitor should also be an X5R type between 2.2μF and
10μF. A larger capacitor should be used if lower peak-topeak output ripple and better line regulation is desired.
Table 1. Example Inductors
SUPPLIER
VENDOR/PART
L
DCR (Ω)/
(μH) IMAX (mA)
DIMENSIONS
(mm)
CONTACT
INFORMATION
Chip Inductors
Murata
LQH31C
LQH32C-Low Profile
Taiyo Yuden
LB2016
Toko
LLB2520
Coilcraft
DO3314
DO1606T
Sumida
CMD4D06
CDRJ2D1BLD
www.murata.com
22
22
3/160
0.7/250
3.2 × 1.6 × 1.8
3.2 × 2.5 × 1.6
15
22
33
0.7/130
1/105
1.7/85
2.0 × 1.6 × 1.6
www.t-yuden.com
(408) 573-4150
15
22
33
1.7/180
2.5/160
3.8/130
2.5 × 2.0 × 1.6
www.tokoam.com
(847) 297-0070
15
22
15
22
33
0.86/650
1.2/500
0.4/700
0.5/500
0.74/450
3.3 × 3.3 × 1.4
www.coilcraft.com
(847) 639-6400
15
22
33
15
22
33
0.5/400 6.6 × 5.8 × 0.8
0.8/300
1.3/240
0.175/350 3.2 × 3.2 × 2.0
0.255/300
0.37/240
Table 2. Capacitor Vendor Information
PHONE
WEBSITE
AVX
(803) 448-9411
www.avxcorp.com
Murata
(714) 852-2001
www.murata.com
Taiyo Yuden
(408) 573-4150
www.t-yuden.com
TDK
(847) 803-6100
www.component.tdk.com
PCB Layout Guidelines
The high speed operation of the LTC3459 demands careful attention to board layout. You will not get advertised
performance with a careless layout. Figure 4 shows the
recommended component placement for the TSOT version of the part. A large ground pin copper area will help
to lower the chip temperature.
RECOMMENDED COMPONENT
PLACEMENT. TRACES CARRYING
CURRENT ARE DIRECT. TRACE
AREA AT FB PIN IS SMALL. LEAD
LENGTH TO BATTERY IS SHORT
6.5 × 5.3 × 2.0
www.sumida.com
(847) 956-0666
VIN
1
SW
VIN 6
2
GND VOUT 5
3
FB SHDN 4
SHDN
VOUT
3459 F04
Figure 4. Recommended Component
Placement for a Single-Layer Board
3459fc
8
LTC3459
TYPICAL APPLICATIONS
Very low operating quiescent current and synchronous
operation allow for greater than 85% conversion efficiency
in many applications. Lower output voltages will result in
lower efficiencies since the N- and P-channel RDS(ON)s
will increase. The switching frequency and output power
capability of the LTC3459 are also dependant on input and
output voltages.
The LTC3459 is designed to control peak inductor current
when VIN is greater than or less than VOUT. This allows
current to be controlled during start-up in a boost application, for example, or VOUT to be regulated below VIN when
powered from a fresh battery. Peak current control makes
the LTC3459 an ideal candidate for charging a back-up
source such as a SuperCap. Figure 5 shows an application
where the LTC3459 is used to charge a two-farad, 5V SuperCap from a 3.3V input. A NiCd battery could be charged
by the LTC3459 as well, but that application may require
additional circuitry for proper charge termination.
Charging a SuperCap®
SuperCaps have become a popular alternative to NiCd
batteries as back-up power sources in portable equipment. Capacitance values of one farad and higher are
achievable in small package sizes with leakage currents
in the low microamps. SuperCaps are typically charged
at low currents for several minutes until they reach the
required back-up voltage.
When VOUT is less than ~3.5V, the body of the internal
synchronous P-channel MOSFET rectifier is connected to
VIN, and the SW pin rises a diode above VIN when current
is delivered to the load. While efficiency is compromised
in this mode of operation, current to the SuperCap is
5V from Li-Ion Input
100
15μH*
Li-Ion
BATTERY
VIN
+
VOUT
FB
SHDN
GND
OFF ON
47pF
1M
LTC3459
1μF
VOUT
5V
4.7μF
332k
VIN = 4.2V
90
EFFICIENCY (%)
SW
VIN
2.5V TO 4.2V
VOUT = 5V
VIN = 2.5V
80
70
3459 TA04a
*COILCRAFT DO3314
60
50
0.01
0.1
1
ILOAD (mA)
10
100
3459 TA04b
10V from 3.3V or 5V Input
100
33μH*
VOUT
VIN
2M
LTC3459
1μF
OFF ON
VOUT
10V
SHDN
GND
47pF
4.7μF
FB
280k
3459 TA05a
*COILCRAFT DO3314
EFFICIENCY (%)
90
SW
VIN
3.3V TO 5V
VOUT = 10V
VIN = 5V
80
VIN = 3.3V
70
60
50
0.01
0.1
1
ILOAD (mA)
10
100
3459 TA05b
3459fc
9
LTC3459
TYPICAL APPLICATIONS
controlled, preventing any damaging effects of inrush
current. Proper heat sinking of the package is required in
this application as the die may dissipate 100mW to 200mW
during initial charging. When VOUT is greater than ~3.5V,
normal boost mode operation and efficiency begin, with
the P-channel MOSFET acting as a synchronous switch.
Average input current is a constant 50mA during charging, where the current delivered to the SuperCap varies
somewhat with duty cycle. Once the SuperCap is charged
to 5V, the LTC3459 begins to regulate and the input current is reduced to the amount required to support the load
and/or self discharge of the SuperCap.
L1
SW
VIN
1μF
3.3V
LTC3459
+
OFF ON
VOUT
5V
VOUT
FB
SHDN
GND
1M
1μF
COUT
2F
332k
3459 F05
COUT: MAXWELL TECHNOLOGIES ULTRACAP PC5-5, 2F, 5V
L1: 33μH, 1.7Ω TAIYO YUDEN LB2016
Figure 5. Charging a SuperCap from a 3.3V Source
PACKAGE DESCRIPTION
DC Package
6-Lead Plastic DFN (2mm × 2mm)
(Reference LTC DWG # 05-08-1703)
R = 0.115
TYP
0.56 p 0.05
(2 SIDES)
0.675 p0.05
2.50 p0.05
1.15 p0.05 0.61 p0.05
(2 SIDES)
PACKAGE
OUTLINE
PIN 1 BAR
TOP MARK
(SEE NOTE 6)
0.38 p 0.05
4
2.00 p0.10
(4 SIDES)
PIN 1
CHAMFER OF
EXPOSED PAD
3
0.25 p 0.05
0.50 BSC
1.42 p0.05
(2 SIDES)
0.200 REF
RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS
6
0.75 p0.05
1
(DC6) DFN 1103
0.25 p 0.05
0.50 BSC
1.37 p0.05
(2 SIDES)
0.00 – 0.05
BOTTOM VIEW—EXPOSED PAD
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WCCD-2)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE
TOP AND BOTTOM OF PACKAGE
3459fc
10
LTC3459
PACKAGE DESCRIPTION
DCB Package
6-Lead Plastic DFN (2mm × 3mm)
(Reference LTC DWG # 05-08-1715)
R = 0.115
TYP
R = 0.05
TYP
2.00 ±0.10
(2 SIDES)
0.70 ±0.05
3.55 ±0.05
PACKAGE
OUTLINE
1.65 ±0.05
(2 SIDES)
3.00 ±0.10
(2 SIDES)
0.40 ± 0.10
4
6
1.65 ± 0.10
(2 SIDES)
2.15 ±0.05
PIN 1 NOTCH
R0.20 OR 0.25
× 45° CHAMFER
PIN 1 BAR
TOP MARK
(SEE NOTE 6)
3
0.25 ± 0.05
0.50 BSC
1.35 ±0.05
(2 SIDES)
0.25 ± 0.05
0.50 BSC
0.75 ±0.05
0.200 REF
(DCB6) DFN 0405
1
1.35 ±0.10
(2 SIDES)
RECOMMENDED SOLDER PAD
PITCH AND DIMENSIONS
0.00 – 0.05
NOTE:
1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (TBD)
2. DRAWING NOT TO SCALE
3. ALL DIMENSIONS ARE IN MILLIMETERS
4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE
MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE
BOTTOM VIEW—EXPOSED PAD
5. EXPOSED PAD SHALL BE SOLDER PLATED
6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION
ON THE TOP AND BOTTOM OF PACKAGE
S6 Package
6-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1636)
0.62
MAX
2.90 BSC
(NOTE 4)
0.95
REF
1.22 REF
3.85 MAX 2.62 REF
1.4 MIN
2.80 BSC
1.50 – 1.75
(NOTE 4)
PIN ONE ID
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
0.30 – 0.45
6 PLCS (NOTE 3)
0.95 BSC
0.80 – 0.90
0.20 BSC
0.01 – 0.10
1.00 MAX
DATUM ‘A’
0.30 – 0.50 REF
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
0.09 – 0.20
(NOTE 3)
1.90 BSC
S6 TSOT-23 0302 REV B
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
3459fc
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
LTC3459
TYPICAL APPLICATION
3.3V from a 2 AA Alkaline Input
L1
15μH
SW
+
C1
2.2μF
+
OFF ON
VOUT
VIN
R1
604k
LTC3459
SHDN
C2
47pF
C3
4.7μF
FB
R2
365k
GND
VOUT = 3.3V
90
VOUT
3.3V
VIN = 3V
EFFICIENCY (%)
VIN
1.8V TO 3V
2 AA
CELLS
100
80
VIN = 1.8V
70
3459 TA06a
60
C1: TDK C1608X5R1A225MT
C2: TDK C0603COG1E470J
C3: TDK C2012X5ROJ475K
L1: COILCRAFT DO3314-153MXB
R1: PANASONIC ERJ3EKF6043V
R2: PANASONIC ERJ3EKF3653V
50
0.01
0.1
1
ILOAD (mA)
10
100
3459 TA06b
RELATED PARTS
PART NUMBER DESCRIPTION
COMMENTS
LT1310
1.5A ISW, 4.5MHz, High Efficiency Step-Up DC/DC Converter
VIN: 2.75V to 18V, VOUT(MAX) = 35V, IQ = 12mA, ISD < 1μA, MS10E
LT1613
550mA ISW, 1.4MHz, High Efficiency Step-Up DC/DC Converter
VIN: 0.9V to 10V, VOUT(MAX) = 34V, IQ = 3mA, ISD < 1μA, ThinSOT
LT1615/
LT1615-1
300mA/80mA ISW, Constant Off-Time, High Efficiency
Step-Up DC/DC Converter
VIN: 1.2V to 15V, VOUT(MAX) = 34V, IQ = 20μA, ISD < 1μA, ThinSOT
LT1618
1.5A ISW, 1.4MHz, High Efficiency Step-Up DC/DC Converter
VIN: 1.6V to 18V, VOUT(MAX) = 35V, IQ = 1.8mA, ISD < 1μA, MS10
LT1944 (Dual)
Dual Output 350mA ISW, Constant Off-Time, High Efficiency
Step-Up DC/DC Converter
VIN: 1.2V to 15V, VOUT(MAX) = 34V, IQ = 20μA, ISD < 1μA, MS10
LT1945 (Dual)
Dual Output Pos/Neg 350mA ISW, Constant Off-Time,
High Efficiency Step-Up DC/DC Converter
VIN: 1.2V to 15V, VOUT(MAX) = ±34V, IQ = 20μA, ISD < 1μA, MS10
LT1946/
LT1946A
1.5A ISW, 1.2MHz/2.7MHz, High Efficiency Step-Up
DC/DC Converter
VIN: 2.45V to 16V, VOUT(MAX) = 34V, IQ = 3.2mA, ISD < 1μA, MS8
LT1949/
LT1949-1
550mA ISW, 600kHz/1.1MHz, High Efficiency Step-Up
DC/DC Converter
VIN: 1.5V to 12V, VOUT(MAX) = 28V, IQ = 4.5mA, ISD < 25μA,
SO-8, MS8
LT1961
1.5A ISW, 1.25MHz, High Efficiency Step-Up DC/DC Converter
VIN: 3V to 25V, VOUT(MAX) = 35V, IQ = 0.9mA, ISD < 6μA, MS8E
LTC3400/
LTC3400B
600mA ISW, 1.2MHz, Synchronous Step-Up DC/DC Converter
VIN: 0.5V to 5V, VOUT(MAX) = 5V, IQ = 19μA/300μA, ISD < 1μA, ThinSOT
LTC3401
1A ISW, 3MHz, Synchronous Step-Up DC/DC Converter
VIN: 0.5V to 5V, VOUT(MAX) = 6V, IQ = 38μA, ISD < 1μA, MS10
LTC3402
2A ISW, 3MHz, Synchronous Step-Up DC/DC Converter
VIN: 0.5V to 5V, VOUT(MAX) = 6V, IQ = 38μA, ISD < 1μA, MS10
LTC3425
5A ISW, 8MHz, 4-Phase Synchronous Step-Up DC/DC
Converter, QFN32
VIN: 0.5V to 4.5V, VOUT(MAX) = 5.25V, IQ = 12μA, ISD < 1μA,
LTC3429
600mA, 500kHz, Synchronous Step-Up DC/DC Converter with
Output Disconnect and Soft-Start
VIN: 0.5V to 5V, VOUT(MAX) = 5V, IQ = 20μA/300μA, ISD < 1μA, ThinSOT
LT3460
320mA ISW, 1.3MHz, High Efficiency Step-Up DC/DC Converter
VIN: 0.5V to 5V, VOUT(MAX) = 5V, IQ = 20μA/300μA, ISD < 1μA, ThinSOT
LT3464
85mA ISW, Constant Off-Time, High Efficiency Step-Up DC/DC
Converter with Integrated Schottky/Output Disconnect
VIN: 2.3V to 10V, VOUT(MAX) = 34V, IQ = 25μA, ISD < 1μA, ThinSOT
3459fc
12 Linear Technology Corporation
LT 1208 REV C • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
© LINEAR TECHNOLOGY CORPORATION 2007