Datasheet LT1613CS5 Datasheet (Linear Technology)

1

LT1613

1.4MHz, Single Cell DC/DC

Converter in 5-Lead SOT-23

■

Uses Tiny Capacitors and Inductor

■

Internally Compensated

■

Fixed Frequency 1.4MHz Operation

■

Operates with VIN as Low as 1.1V

■

3V at 30mA from a Single Cell

■

5V at 200mA from 3.3V Input

■

15V at 60mA from Four Alkaline Cells

■

High Output Voltage: Up to 34V

■

Low Shutdown Current: <1µA

■

Low V

CESAT

Switch: 300mV at 300mA

■

Tiny 5-Lead SOT-23 Package

The LT®1613 is the industry’s first 5-lead SOT-23 current
mode DC/DC converter. Intended for small, low power
applications, it operates from an input voltage as low as

1.1V and switches at 1.4MHz, allowing the use of tiny, low
cost capacitors and inductors 2mm or less in height. Its
small size and high switching frequency enables the
complete DC/DC converter function to take up less than

0.2 square inches of PC board area. Multiple output power
supplies can now use a separate regulator for each output
voltage, replacing cumbersome quasi-regulated ap­proaches using a single regulator and a custom trans­former.

A constant frequency, internally compensated current
mode PWM architecture results in low, predictable output
noise that is easy to filter. The high voltage switch on the
LT1613 is rated at 36V, making the device ideal for boost
converters up to 34V as well as for Single-Ended Primary
Inductance Converter (SEPIC) and flyback designs. The
device can generate 5V at up to 200mA from a 3.3V supply
or 5V at 175mA from four alkaline cells in a SEPIC design.

The LT1613 is available in the 5-lead SOT-23 package.

■

Digital Cameras

■

Pagers

■

Cordless Phones

■

Battery Backup

■

LCD Bias

■

Medical Diagnostic Equipment

■

Local 5V or 12V Supply

■

External Modems

■

PC Cards

Efficiency Curve

LOAD CURRENT (mA)

0 50 100 150 200 250 300 350 400

EFFICIENCY (%)

1613 TA01a

100

95
90
85
80
75
70
65
60
55
50

VIN = 4.2V

VIN = 3.5V

VIN = 2.8V

VIN = 1.5V

Figure 1. 3.3V to 5V 200mA DC/DC Converter

V

IN

V

IN

3.3V

V

OUT

5V
200mA

1613 TA01

SW

L1

4.7µH

D1

GND

LT1613

L1: MURATA LQH3C4R7M24 OR SUMIDA CD43-4R7
C1: AVX TAJA156M010
C2: AVX TAJB226M006
D1: MBR0520

C1
15µF

C2
22µF

R2

12.1k

R1

37.4k

FBSHDN

SHDN

+ +

, LTC and LT are registered trademarks of Linear Technology Corporation.

APPLICATIO S

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FEATURES

TYPICAL APPLICATIO

U

DESCRIPTIO

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2

LT1613

PARAMETER CONDITIONS MIN TYP MAX UNITS

Minimum Operating Voltage 0.9 1.1 V
Maximum Operating Voltage 10 V
Feedback Voltage ● 1.205 1.23 1.255 V
FB Pin Bias Current ● 27 80 nA
Quiescent Current V

SHDN

= 1.5V 3 4.5 mA

Quiescent Current in Shutdown V

SHDN

= 0V, VIN = 2V 0.01 0.5 µA

V

SHDN

= 0V, VIN = 5V 0.01 1.0 µA
Reference Line Regulation 1.5V ≤ VIN ≤ 10V 0.02 0.2 %/V
Switching Frequency ● 1.0 1.4 1.8 MHz
Maximum Duty Cycle ● 82 86 %
Switch Current Limit (Note 3) 550 800 mA
Switch V

CESAT

ISW = 300mA 300 350 mV
Switch Leakage Current VSW = 5V 0.01 1 µA
SHDN Input Voltage High 1V
SHDN Input Voltage Low 0.3 V
SHDN Pin Bias Current V

SHDN

= 3V 25 50 µA

V

SHDN

= 0V 0.01 0.1 µA

(Note 1)

VIN Voltage .............................................................. 10V

SW Voltage................................................–0.4V to 36V

FB Voltage ..................................................... VIN + 0.3V

Current into FB Pin ............................................... ±1mA

SHDN Voltage.......................................................... 10V

Maximum Junction Temperature..........................125°C

Operating Temperature Range

Commercial .............................................0°C to 70°C

Extended Commercial (Note 2)........... –40°C to 85°C

Storage Temperature Range................. –65°C to 150°C

Lead Temperature (Soldering, 10 sec)..................300°C

ABSOLUTE MAXIMUM RA TIN GS

W

WW

U

PACKAGE/ORDER INFORMATION

W

U

U

S5 PART MARKING

LTED

ORDER PART NUMBER

LT1613CS5

SW 1

GND 2

TOP VIEW

S5 PACKAGE

5-LEAD PLASTIC SOT-23

FB 3

5 V

IN

4 SHDN

ELECTRICAL CHARACTERISTICS

The ● denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at TA = 25°C. Commercial grade 0°C to 70°C, VIN = 1.5V, V

SHDN

= VIN unless

otherwise noted. (Note 2)

Consult factory for Industrial and Military grade parts.

Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.

Note 2: The LT1613C 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: Current limit guaranteed by design and/or correlation to static test.

3

LT1613

TYPICAL PERFOR A CE CHARACTERISTICS

UW

SWITCH CURRENT (mA)

0 100 200 300 400 500 600 700

V

CESAT

(mV)

1613 G01

700

600

500

400

300

200

100

0

TA = 25°C

TEMPERATURE (°C)

–50 –25 0 25 50 75 100

SWITCHING FREQUENCY (MHz)

1613 G02

2.00

1.75

1.50

1.25

1.00

0.75

0.50

0.25
0

VIN = 5V

VIN = 1.5V

SHDN PIN VOLTAGE (V)

012345

SHDN PIN BIAS CURRENT (µA)

1613 G03

50

40

30

20

10

0

TA = 25°C

DUTY CYCLE (%)

10 20 30 40 50 60 70 80

CURRENT LIMIT (mA)

1613 G04

1000

900
800
700
600
500
400
300
200

70°C

25°C

–40°C

TEMPERATURE (°C)

–50

FEEDBACK PIN VOLTAGE (V)

1613 G05

1.25

1.24

1.23

1.22

1.21

1.20

VOLTAGE

–25 0 25 50 75 100

Switch V

CESAT

vs Switch Current SHDN Pin Current vs V

SHDN

Oscillator Frequency vs
Temperature

Current Limit vs Duty Cycle

Feedback Pin Voltage

Switching Waveforms, Circuit of Figure 1

V

OUT

100mV/DIV

AC COUPLED

V

SW

5V/DIV

I

SW

200mA/DIV

I

LOAD

= 150mA 200ns/DIV 1613 G06

4

LT1613

PIN FUNCTIONS

UUU

SW (Pin 1): Switch Pin. Connect inductor/diode here.
Minimize trace area at this pin to keep EMI down.

GND (Pin 2): Ground. Tie directly to local ground plane.
FB (Pin 3): Feedback Pin. Reference voltage is 1.23V.

Connect resistive divider tap here. Minimize trace area at
FB. Set V

OUT

according to V

OUT

= 1.23V(1 + R1/R2).

SHDN (Pin 4): Shutdown Pin. Tie to 1V or more to enable
device. Ground to shut down.

VIN (Pin 5): Input Supply Pin. Must be locally bypassed.

BLOCK DIAGRAM

W

–

+

–

+

FF

RQ

S

0.15Ω

SW

DRIVER

COMPARATOR

2

SHUTDOWN

SHDN

4

1

–

+

Σ

RAMP

GENERATOR

R

C

C

C

1.4MHz

OSCILLATOR

GND

1613 • BD

R6
40k

R4
140k

R3
30k

Q2
x10

Q1

Q3

R2
(EXTERNAL)

R1
(EXTERNAL)

R5
40k

V

OUT

V

IN

V

IN

5

FB

FB

3

A2

A1

g

m

The LT1613 is a current mode, internally compensated,
fixed frequency step-up switching regulator. Operation
can be best understood by referring to the Block Diagram.
Q1 and Q2 form a bandgap reference core whose loop is
closed around the output of the regulator. The voltage
drop across R5 and R6 is low enough such that Q1 and Q2
do not saturate, even when VIN is 1V. When there is no
load, FB rises slightly above 1.23V, causing VC (the error
amplifier’s output) to decrease. Comparator A2’s output
stays high, keeping switch Q3 in the off state. As increased
output loading causes the FB voltage to decrease, A1’s
output increases. Switch current is regulated directly on a
cycle-by-cycle basis by the VC node. The flip flop is set at
the beginning of each switch cycle, turning on the switch.
When the summation of a signal representing switch
current and a ramp generator (introduced to avoid
subharmonic oscillations at duty factors greater than

OPERATIO

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50%) exceeds the VC signal, comparator A2 changes
state, resetting the flip flop and turning off the switch.
More power is delivered to the output as switch current is
increased. The output voltage, attenuated by external
resistor divider R1 and R2, appears at the FB pin, closing
the overall loop. Frequency compensation is provided
internally by RC and CC. Transient response can be opti­mized by the addition of a phase lead capacitor CPL in
parallel with R1 in applications where large value or low
ESR output capacitors are used.

As the load current is decreased, the switch turns on for a
shorter period each cycle. If the load current is further
decreased, the converter will skip cycles to maintain
output voltage regulation. If the FB pin voltage is increased
significantly above 1.23V, the LT1613 will enter a low
power state where quiescent current falls to approxi­mately 100µA.

5

LT1613

OPERATIO

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LAYOUT

The LT1613 switches current at high speed, mandating
careful attention to layout for proper performance.

You

will not get advertised performance with careless layouts.

Figure 2 shows recommended component placement for
a boost (step-up) converter. Follow this closely in your
PCB layout. Note the direct path of the switching loops.
Input capacitor C1

must

be placed close (<5mm) to the IC
package. As little as 10mm of wire or PC trace from CIN to
VIN will cause problems such as inability to regulate or
oscillation.

The ground terminal of output capacitor C2 should tie
close to Pin 2 of the LT1613. Doing this reduces dI/dt in the
ground copper which keeps high frequency spikes to a
minimum. The DC/DC converter ground should tie to the
PC board ground plane at one place only, to avoid intro­ducing dI/dt in the ground plane.

A SEPIC (single-ended primary inductance converter)
schematic is shown in Figure 3. This converter topology
produces a regulated output voltage that spans (i.e., can
be higher or lower than) the output. Recommended com­ponent placement for a SEPIC is shown in Figure 4.

D1

1613 F02

GROUND

VIAS TO

GROUND

PLANE

SHUTDOWN

V

IN

L1

V

OUT

R2

R1

+

C2

+

C1

15

2

34

Figure 2. Recommended Component Placement for Boost
Converter. Note Direct High Current Paths Using Wide PCB
Traces. Minimize Area at Pin 3 (FB). Use Vias to Tie Local
Ground Into System Ground Plane. Use Vias at Location Shown
to Avoid Introducing Switching Currents Into Ground Plane

V

IN

V

OUT

5V/150mA

1613 F03

SW

L1A

22µH

L1B
22µH

D1

GND

LT1613

C1, C2: AVX TAJA156M016
C3: TAIYO YUDEN JMK325BJ226MM
D1: MOTOROLA MBR0520
L1, L2: MURATA LQH3C220

R2

32.4k

R1

100k

C3

1µF

FBSHDN

C1
15µF

V

IN

4V TO

7V

+

C2
15µF

+

SHDN

Figure 3. Single-Ended Primary Inductance Converter (SEPIC)
Generates 5V from An Input Voltage Above or Below 5V

D1

C3

1613 F04

GROUND

VIAS TO

GROUND

PLANE

SHUTDOWN

V

IN

L1AL1B

V

OUT

R2

R1

+

C2

+

C1

15

2

34

Figure 4. Recommended Component Placement for SEPIC

COMPONENT SELECTION
Inductors

Inductors used with the LT1613 should have a saturation
current rating (where inductance is approximately 70% of
zero current inductance) of approximately 0.5A or greater.
DCR of the inductors should be 0.5Ω or less. For boost
converters, inductance should be 4.7µH for input voltage
less than 3.3V and 10µH for inputs above 3.3V. When
using the device as a SEPIC, either a coupled inductor or
two separate inductors can be used. If using separate
inductors, 22µH units are recommended for input voltage
above 3.3V. Coupled inductors have a beneficial mutual
inductance, so a 10µH coupled inductor results in the
same ripple current as two 20µH uncoupled units.

6

LT1613

OPERATIO

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Table 1 lists several inductors that will work with the
LT1613, although this is not an exhaustive list. There are
many magnetics vendors whose components are suitable
for use.

Diodes

A Schottky diode is recommended for use with the LT1613.
The Motorola MBR0520 is a very good choice. Where the
input to output voltage differential exceeds 20V, use the
MBR0530 (a 30V diode). If cost is more important than
efficiency, the 1N4148 can be used, but only at low current
loads.

Capacitors

The input bypass capacitor must be placed physically
close to the input pin. ESR is not critical and in most cases
an inexpensive tantalum is appropriate.

The choice of output capacitor is far more important. The
quality of this capacitor is the greatest determinant of the
output voltage ripple. The output capacitor must have
enough capacitance to satisfy the load under transient
conditions and it must shunt the switched component of
current coming through the diode. Output voltage ripple
results when this switched current passes through the
finite output impedance of the output capacitor. The
capacitor should have low impedance at the 1.4MHz
switching frequency of the LT1613. At this frequency, the
impedance is usually dominated by the capacitor’s equiva­lent series resistance (ESR). Choosing a capacitor with

lower ESR will result in lower output ripple.
Ceramic capacitors can be used with the LT1613 provided

loop stability is considered. A tantalum capacitor has
some ESR and this causes an “ESR zero” in the regulator
loop. This zero is beneficial to loop stability. The internally
compensated LT1613 does not have an accessible com­pensation node, but other circuit techniques can be em­ployed to counteract the loss of the ESR zero, as detailed
in the next section.

Some capacitor types appropriate for use with the LT1613
are listed in Table 2.

OPERATION WITH CERAMIC CAPACITORS

Because the LT1613 is internally compensated, loop sta­bility must be carefully considered when choosing an
output capacitor. Small, low cost tantalum capacitors
have some ESR, which aids stability. However, ceramic
capacitors are becoming more popular, having attractive
characteristics such as near-zero ESR, small size and
reasonable cost. Simply replacing a tantalum output ca­pacitor with a ceramic unit will decrease the phase margin,
in some cases to unacceptable levels. With the addition of
a phase lead capacitor (CPL) and isolating resistor (R3),
the LT1613 can be used successfully with ceramic output
capacitors as described in the following figures.

A boost converter, stepping up 2.5V to 5V, is shown in
Figure 5. Tantalum capacitors are used for the input and
output (the input capacitor is not critical and has little

Table 1. Inductor Vendors

VENDOR PHONE URL PART COMMENT

Sumida [phone] www.sumida.com CLS62-22022 22µH Coupled

CD43-220 22µH

Murata [phone] www.murata.com LQH3C-220 22µH, 2mm Height

LQH3C-100 10µH
LQH3C-4R7 4.7µH

Coiltronics [phone] www.coiltronics.com CTX20-1 20µH Coupled, Low DCR

Table 2. Capacitor Vendors

VENDOR PHONE URL PART COMMENT

Taiyo Yuden [phone] www.t-yuden.com Ceramic Caps X5R Dielectric
AVX [phone] www.avxcorp.com Ceramic Caps

Tantalum Caps

Murata [phone] www.murata.com Ceramic Caps

7

LT1613

OPERATIO

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resulting in a severely underdamped response. By adding
R3 and CPL as detailed in Figure 8’s schematic, phase
margin is restored, and transient response to the same
load step is pictured in Figure 9. R3 isolates the device FB
pin from fast edges on the V

OUT

node due to parasitic PC

trace inductance.
Figure 10’s circuit details a 5V to 12V boost converter,

delivering up to 130mA. The transient response to a load
step of 10mA to 130mA, without CPL, is pictured in
Figure 11. Although the ringing is less than that of the
previous example, the response is still underdamped and
can be improved. After adding R3 and CPL, the improved
transient response is detailed in Figure 12.

Figure 13 shows a SEPIC design, converting a 3V to 10V
input to a 5V output. The transient response to a load step
of 20mA to 120mA, without CPL and R3, is pictured in
Figure 14. After adding these two components, the im­proved response is shown in Figure 15.

effect on loop stability, as long as minimum capacitance
requirements are met). The transient response to a load
step of 50mA to 100mA is pictured in Figure 6. Note the
“double trace,” due to the ESR of C2. The loop is stable and
settles in less than 100µs. In Figure 7, C2 is replaced by a
10µF ceramic unit. Phase margin decreases drastically,

V

IN

V

OUT

5V

1613 F05

SW

L1

10µH

D1

GND

LT1613

C1: AVX TAJA156M010R
C2: AVX TAJA226M006R
D1: MOTOROLA MBR0520
L1: MURATA LQH3C100

R2

12.1k

R1

37.4k

FBSHDN

C1
15µF

V

IN

2.5V

+

C2
22µF

+

SHDN

Figure 5. 2.5V to 5V Boost Converter with “A”
Case Size Tantalum Input and Output Capacitors

V

IN

V

OUT

5V

C

PL

330pF

1613 F08

SW

L1

10µH

D1

GND

LT1613

C1: AVX TAJA156M010R
C2: TAIYO YUDEN LMK325BJ106MN
D1: MBR0520
L1: MURATA LQH3C100K04

R2

12.1k

R3

10k

R1

37.4k

FBSHUTDOWN

C1
15µF

V

IN

2.5V

C2
10µF

SHDN

+

V

OUT

20mV/DIV

AC COUPLED

LOAD CURRENT

100mA

50mA

200µs/DIV

1613 F06

Figure 6. 2.5V to 5V Boost Converter Transient
Response with 22µF Tantalum Output Capacitor.
Apparent Double Trace on V

OUT

Is Due to Switching

Frequency Ripple Current Across Capacitor ESR

V

OUT

20mV/DIV

AC COUPLED

LOAD CURRENT

100mA

200µs/DIV

1613 F07

50mA

Figure 7. 2.5V to 5V Boost Converter with
10µF Ceramic Output Capacitor, No C

PL

Figure 8. 2.5V to 5V Boost Converter with Ceramic
Output Capacitor. CPL Added to Increase Phase Margin,
R3 Isolates FB Pin from Fast Edges

V

OUT

20mV/DIV

AC COUPLED

LOAD CURRENT

100mA

200µs/DIV

1613 F09

50mA

Figure 9. 2.5V to 5V Boost Converter with 10µF Ceramic
Output Capacitor, 330pF CPL and 10k in Series with FB Pin

8

LT1613

OPERATIO

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V

IN

V

OUT

12V
130mA

C

PL

200pF

1613 F10

SW

L1

10µH

D1

GND

LT1613

C1: AVX TAJB226M010
C2: TAIYO YUDEN EMK325BJ475MN
D1: MOTOROLA MBR0520
L1: MURATA LQH3C100

R2

12.3k

R3

10k

R1
107k

FBSHUTDOWN

C1
22µF

V

IN

5V

C2

4.7µF

SHDN

+

Figure 10. 5V to 12V Boost Converter with 4.7µF Ceramic
Output Capacitor, CPL Added to Increase Phase Margin

V

OUT

100mV/DIV

AC COUPLED

LOAD CURRENT

130mA

200µs/DIV

1613 F11

10mA

Figure 11. 5V to 12V Boost Converter
with 4.7µF Ceramic Output Capacitor

V

IN

V

OUT

5V

1613 F13

SW

L1

22µH

L2

22µH

C

PL

330pF

D1

GND

LT1613

C1: AVX TAJB226M010
C2: TAIYO YUDEN LMK325BJ106MN
C3: TAIYO YUDEN LMK212BJ105MG
D1: MOTOROLA MBR0520
L1, L2: MURATA LQH3C220

R2

12.1k

R1

37.4k

R3

10k

C3

1µF

FBSHUTDOWN

C1
22µF

V

IN

3V TO

10V

C2
10µF

SHDN

+

V

OUT

100mV/DIV

AC COUPLED

LOAD CURRENT

130mA

200µs/DIV

1613 F12

10mA

Figure 12. 5V to 12V Boost Converter with 4.7µF
Ceramic Output Capacitor and 200pF Phase-Lead
Capacitor CPL and 10k in Series with FB Pin

Figure 13. 5V Output SEPIC with Ceramic
Output Capacitor. CPL Adds Phase Margin

V

OUT

50mV/DIV

AC COUPLED

LOAD CURRENT

120mA

200µs/DIV

1613 F14

20mA

Figure 14. 5V Output SEPIC with 10µF
Ceramic Output Capacitor. No CPL. VIN = 4V

V

OUT

50mV/DIV

AC COUPLED

LOAD CURRENT

120mA

200µs/DIV

1613 F15

20mA

Figure 15. 5V Output SEPIC with 10µF Ceramic Output
Capacitor, 330pF CPL and 10k in Series with FB Pin

9

LT1613

START-UP/SOFT-START

When the LT1613 SHDN pin voltage goes high, the device
rapidly increases the switch current until internal current
limit is reached. Input current stays at this level until the
output capacitor is charged to final output voltage. Switch
current can exceed 1A. Figure 16’s oscillograph details
start-up waveforms of Figure 17’s SEPIC into a 50Ω load
without any soft-start. The output voltage reaches final
value in approximately 200µs, while input current reaches
400mA. Switch current in a SEPIC is 2x the input current,
so the switch is conducting approximately 800mA peak.

Soft-start reduces the inrush current by taking more time
to reach final output voltage. A soft-start circuit consisting
of Q1, RS1, RS2 and CS1 as shown in Figure 17 can be used
to limit inrush current to a lower value. Figure 18 pictures
V

OUT

and input current with RS2 of 33kΩ and CS of 10nF.

Input current is limited to a peak value of 200mA as the

OPERATIO

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V

IN

V

OUT

5V

1613 F17

SW

L1

22µH

L2

22µH

C

PL

330pF

D1

GND

LT1613

C1: AVX TAJB226M006
C2: TAIYO YUDEN LMK325BJ106MN
C3: TAIYO YUDEN LMK212BJ105MG

R2

12.1k

R

LOAD

Q1
2N3904

R1

37.4k

R3

10k

R

S1

33k

C3

1µF

FBV

S

SOFT-START COMPONENTS

C1

22µF

V

IN

4V

C2
10µF

SHDN

+

R

S2

33k

C

S

10nF/

33nF

D1: MOTOROLA MBR0520
L1, L2: MURATA LQH3C220

time required to reach final value increases to 1.7ms. In
Figure 19, CS is increased to 33nF. Input current does not
exceed the steady-state current the device uses to supply
power to the 50Ω load. Start-up time increases to 4.3ms.
CS can be increased further for an even slower ramp, if
desired.

V

OUT

2V/DIV

200µs/DIV

1613 F16

Figure 16. Start-Up Waveforms of
Figure 17’s SEPIC Into 50Ω Load

I

IN

200mA/DIV

V

SHDN

5V/DIV

V

OUT

2V/DIV

500µs/DIV

1613 F18

Figure 18. Soft-Start Components in Figure 17’s SEPIC
Reduces Inrush Current. CSS = 10nF, R

LOAD

= 50Ω

I

IN

200mA/DIV

V

S

5V/DIV

V

OUT

2V/DIV

1ms/DIV

1613 F18

Figure 19. Increasing CS to 33nF Further
Reduces Inrush Current. R

LOAD

= 50Ω

I

IN

200mA/DIV

V

S

5V/DIV

Figure 17. 5V SEPIC with Soft-Start Components

10

LT1613

TYPICAL APPLICATIO S

U

V

IN

V

OUT

5V
175mA

1613 • TA03

SW

L1

22µH

L2
22µH

C3

1µF

D1

GND

LT1613

L1, L2: MURATA LQH3C220
C3: AVX 1206YG105 CERAMIC
D1: MBR0520

C2
22µF

121k

374k

FBSHDN

C1
15µF

6.5V TO 4V

SHDN

+

+

4-CELL

4-Cell to 5V SEPIC DC/DC Converter

V

IN

V

OUT

15V/30mA

1613 TA04

SW

L1

10µH

D1

GND

LT1613

C1: AVX TAJB226M016
C2: AVX TAJA475M025
D1: MOTOROLA MBR0520
L1: MURATA LQH3C100

R2

12.1k

R1
137k
1%

10k

FBSHDN

C1
22µF

V

IN

3.5V TO
8V

+

C2

4.7µF

+

SHDN

1nF

LOAD CURRENT (mA)

0 102030405060708090100

EFFICIENCY (%)

1613 TA04a

85

80

75

70

65

60

55

50

VIN = 6.5V

VIN = 5V

VIN = 3.6V

D1

D4

0.22µF

L1

5.4µH

0.22µF

48.7k

1613 TA05

274k

C1

4.7µF

V

IN

3.3V

C2

4.7µF

1µF

1µF

1µF

0.22µF

AV

DD

8V
70mA

0.22µF: TAIYO YUDEN EMK212BJ224MG
1µF: TAIYO YUDEN LMK212BJ105MG

4.7µF: TAIYO YUDEN LMK316BJ475ML
D1: MOTOROLA MBRO520
D2, D3, D4: BAT54S
L1: SUMIDA CDRH5D185R4

V

ON

24V
5mA

V

OFF

–8V
5mA

D3

D2

V

IN

SW

GND

LT1613

FBSHDN

4-Cell to 15V/30mA DC/DC Converter

Efficiency

3.3V to 8V/70mA, –8V/5mA, 24V/5mA TFT LCD Bias Supply Uses All Ceramic Capacitors

11

LT1613

TYPICAL APPLICATIO S

U

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.

33.2k

1613 TA08

102k

V

IN

7V TO 3.6V

270pF

C2

1µF

C1: TAIYO YUDEN JMK316BJ106ML
C2, C3, C4: TAIYO YUDEN EMK212BJ105MG
C5: TAIYO YUDEN JMK212BJ475MG
D1: MOTOROLA MBR0520
D2, D3: BAT54
T1: COILCRAFT CCI8244A [phone]

V

IN

SW

GND

LT1613

FBSHDN

SHUTDOWN

C1
10µF

C4
1µF

D3

3

4

6

T1

1

5

2

D1

D2

C5

4.7µF

C3
1µF

15V/10mA

5V/50mA

–7.5V/10mA

33.2k

1613 TA07

102k

V

IN

7V TO 3.6V

270pF

C2

1µF

C1: TAIYO YUDEN JMK316BJ106ML
C2, C3, C4: TAIYO YUDEN EMK212BJ105MG
C5: TAIYO YUDEN JMK212BJ475MG
D1: MOTOROLA MBR0520
D2, D3: BAT54
T1: COILCRAFT CCI8245A [phone]

V

IN

SW

GND

LT1613

FBSHDN

SHUTDOWN

C1
10µF

C5

4.7µF

D1

3

4

6

T1

1

5

2

D2

D3

C4
1µF

C3
1µF

15V/10mA

12V/10mA

5V/50mA

4-Cell to 5V/50mA, 12V/10mA, 15V/10mA Digital Camera Power Supply

4-Cell to 5V/50mA, 15V/10mA, –7.5V/10mA Digital Camera Power Supply

12

LT1613

1613f LT/TP 1299 4K • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 1997

Linear Technology Corporation

1630 McCarthy Blvd., Milpitas, CA 95035-7417

[phone] ● FAX: [phone]

●

www.linear-tech.com

TYPICAL APPLICATIONS

U

PACKAGE DESCRIPTION

U

Dimensions in inches (millimeters) unless otherwise noted.

S5 Package

5-Lead Plastic SOT-23

(LTC DWG # 05-08-1633)

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PART NUMBER DESCRIPTION COMMENTS

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LTC1474 Low Quiescent Current, High Efficiency Step-Down Converter 94% Efficiency, 10µA IQ, 9V to 5V at 250µA
LT1521 300mA Low Dropout Regulator with Micropower Quiescent 500mV Dropout, 300mA Output Current, 12µA I

Q

Current and Shutdown

LTC1517-5 Micropower, Regulated Charge Pump 3-Cells to 5V at 20mA, SOT-23 Package, 6µA I

Q

LT1610 1.7MHz Single Cell Micropower DC/DC Converter 30µA IQ, MSOP Package, Internal Compensation
LT1611 Inverting 1.4MHz Switching Regulator 5V to –5V at 150mA, Low Output Noise
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V

IN

16V
20mA

1613 TA06

SW

L1

2.2µH

D1

GND

LT1613

C1: AVX TAJA4R7M010
C2: TAIYO YUDEN LMK212BJ105MG
D1: BAT54S DUAL DIODE
L1: MURATA LQH3C2R2

13.7k
1%

165k

1%

FBSHDN

C1

4.7µF

V

IN

2.7V

TO 4.5V

C2
1µF
X5R
CERAMIC

SHDN

+

1.50 – 1.75

(0.059 – 0.069)

0.35 – 0.55

(0.014 – 0.022)

0.35 – 0.50

(0.014 – 0.020)

FIVE PLACES (NOTE 2)

S5 SOT-23 0599

0.90 – 1.45

(0.035 – 0.057)

0.90 – 1.30

(0.035 – 0.051)

0.00 – 0.15

(0.00 – 0.006)

0.09 – 0.20

(0.004 – 0.008)

(NOTE 2)

2.60 – 3.00

(0.102 – 0.118)

NOTE:

1. DIMENSIONS ARE IN MILLIMETERS

2. DIMENSIONS ARE INCLUSIVE OF PLATING

3. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR

4. MOLD FLASH SHALL NOT EXCEED 0.254mm

5. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ)

0.95

(0.037)

REF

2.80 – 3.00

(0.110 – 0.118)

(NOTE 3)

1.90

(0.074)

REF

Li-Ion to 16V/20mA Step-Up DC/DC Converter