1
LT1930/LT1930A
APPLICATIO S
U
FEATURES
DESCRIPTIO
U
TYPICAL APPLICATIO
U
1A, 1.2MHz/2.2MHz,
Step-Up DC/DC Converters
in ThinSOT
1.2MHz Switching Frequency (LT1930)
2.2MHz Switching Frequency (LT1930A)
Low V
CESAT
Switch: 400mV at 1A
High Output Voltage: Up to 34V
5V at 480mA from 3.3V Input (LT1930)
12V at 250mA from 5V Input (LT1930A)
Wide Input Range: 2.6V to 16V
Uses Small Surface Mount Components
Low Shutdown Current: <1µA
Low Profile (1mm) ThinSOT
TM
Package
Pin-for-Pin Compatible with the LT1613
Figure 1. 5V to 12V, 300mA Step-Up DC/DC Converter
TFT-LCD Bias Supply
Digital Cameras
Cordless Phones
Battery Backup
Medical Diagnostic Equipment
Local 5V or 12V Supply
External Modems
PC Cards
xDSL Power Supply
Efficiency
The LT
®
1930 and LT1930A
are the industry’s highest
power SOT-23 switching regulators. Both include an
internal 1A, 36V switch allowing high current outputs to be
generated in a small footprint. The LT1930 switches at
1.2MHz, allowing the use of tiny, low cost and low height
capacitors and inductors. The faster LT1930A switches at
2.2MHz, enabling further reductions in inductor size.
Complete regulator solutions approaching one tenth of a
square inch in area are achievable with these devices.
Multiple output power supplies can now use a separate
regulator for each output voltage, replacing cumbersome
quasi-regulated approaches using a single regulator and
custom transformers.
A constant frequency internally compensated current mode
PWM architecture results in low, predictable output noise
that is easy to filter. Low ESR ceramic capacitors can be
used at the output, further reducing noise to the millivolt
level. The high voltage switch on the LT1930/LT1930A 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 LT1930 can
generate 5V at up to 480mA from a 3.3V supply or 5V at
300mA from four alkaline cells in a SEPIC design.
The LT1930/LT1930A are available in the 5-lead ThinSOT
package.
GND
V
IN
SW
SHDN FB
V
IN
5V
4
51
3
D1
L1
10µH
2
R1
113k
LT1930
1930/A F01
C2
4.7µF
C3*
10pF
C1
2.2µF
R2
13.3k
V
OUT
12V
300mA
C1: TAIYO-YUDEN X5R LMK212BJ225MG
C2: TAIYO-YUDEN X5R EMK316BJ475ML
D1: ON SEMICONDUCTOR MBR0520
L1: SUMIDA CR43-100
*OPTIONAL
SHDN
LOAD CURRENT (mA)
0
EFFICIENCY (%)
70
75
80
400
1930 TA01
65
60
50 100 200 300
55
90
85
V
IN
= 5V
V
IN
= 3.3V
, LTC and LT are registered trademarks of Linear Technology Corporation
ThinSOT is a trademark of Linear Technology Corporation.
2
LT1930/LT1930A
(Note 1)
V
IN
Voltage .............................................................. 16V
SW Voltage ................................................0.4V to 36V
FB Voltage .............................................................. 2.5V
Current Into FB Pin .............................................. ±1mA
SHDN Voltage ......................................................... 10V
Maximum Junction Temperature ......................... 125°C
Operating Temperature Range (Note 2) .. 40°C to 85°C
Storage Temperature Range ................. 65°C to 150°C
Lead Temperature (Soldering, 10 sec)..................300°C
The denotes specifications which apply over the full operating temperature range, otherwise specifications are TA = 25°C.
VIN = 3V, VSHDN = VIN unless otherwise noted. (Note 2)
ORDER PART
NUMBER
LT1930ES5
LT1930AES5
S5 PART MARKING
LTKS
LTSQ
T
JMAX
= 125°C, θ
JA
= 256°C/W
ELECTRICAL CHARACTERISTICS
PACKAGE/ORDER I FOR ATIO
UU
W
ABSOLUTE AXI U RATI GS
WWWU
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: The LT1930E/LT1930AE are 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.
Consult LTC Marketing for parts specified with wider operating temperature ranges.
SW 1
GND 2
TOP VIEW
S5 PACKAGE
5-LEAD PLASTIC SOT-23
FB 3
5 V
IN
4 SHDN
LT1930 LT1930A
PARAMETER CONDITIONS MIN TYP MAX MIN TYP MAX UNITS
Minimum Operating Voltage 2.45 2.6 2.45 2.6 V
Maximum Operating Voltage 16 16 V
Feedback Voltage 1.240 1.255 1.270 1.240 1.255 1.270 V
1.230 1.280 1.230 1.280 V
FB Pin Bias Current V
FB
= 1.255V 120 360 240 720 nA
Quiescent Current V
SHDN
= 2.4V, Not Switching 4.2 6 5.5 8 mA
Quiescent Current in Shutdown V
SHDN
= 0V, V
IN
= 3V 0.01 1 0.01 1 µA
Reference Line Regulation 2.6V V
IN
16V 0.01 0.05 0.01 0.05 %/V
Switching Frequency 1 1.2 1.4 1.8 2.2 2.6 MHz
0.85 1.6 1.6 2.9 MHz
Maximum Duty Cycle 84 90 75 90 %
Switch Current Limit (Note 3) 1 1.2 2 1 1.2 2.5 A
Switch V
CESAT
I
SW
= 1A 400 600 400 600 mV
Switch Leakage Current V
SW
= 5V 0.01 1 0.01 1 µA
SHDN Input Voltage High 2.4 2.4 V
SHDN Input Voltage Low 0.5 0.5 V
SHDN Pin Bias Current V
SHDN
= 3V 16 32 35 70 µA
V
SHDN
= 0V 0 0.1 0 0.1 µA
3
LT1930/LT1930A
TYPICAL PERFOR A CE CHARACTERISTICS
UW
Quiescent Current FB Pin Voltage SHDN Pin Current
Current Limit Switch Saturation Voltage Oscillator Frequency
SW (Pin 1): Switch Pin. Connect inductor/diode here.
Minimize trace area at this pin to reduce EMI.
GND (Pin 2): Ground. Tie directly to local ground plane.
FB (Pin 3): Feedback Pin. Reference voltage is 1.255V.
Connect resistive divider tap here. Minimize trace area at
FB. Set V
OUT
according to V
OUT
= 1.255V(1 + R1/R2).
UU
U
PI FU CTIO S
SHDN (Pin 4): Shutdown Pin. Tie to 2.4V or more to enable
device. Ground to shut down.
V
IN
(Pin 5): Input Supply Pin. Must be locally bypassed.
TEMPERATURE (°C)
–50 –25
QUIESCENT CURRENT (mA)
50 75
7.0
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
1930/A G01
0 25 100
NOT SWITCHING
LT1930A
LT1930
TEMPERATURE (°C)
–50
1.22
FB VOLTAGE (V)
1.23
1.24
1.25
1.26
1.28
–25 02550
1930/A G02
75 100
1.27
SHDN PIN VOLTAGE (V)
0
SHDN PIN CURRENT (µA)
20
30
40
35
1930/A G03
10
0
–10 12 4
50
60
70
80
90
6
LT1930A
LT1930
DUTY CYCLE (%)
10
CURRENT LI MIT (A)
0.8
1.2
1930/A G04
0.4
03020 5040 7060 9080
1.6
0.6
1.0
0.2
1.4
SWITCH CURRENT (A)
0
0
V
CESAT
(V)
0.05
0.15
0.20
0.25
0.8
0.45
1930/A G05
0.10
0.4 1.2
0.6
0.2 1.0
0.30
0.35
0.40
TEMPERATURE (°C)
50 –25 0
FREQUENCY (MHz)
2.5
2.3
2.1
1.9
1.7
1.5
1.3
1.1
0.9
0.7
0.5 25 50 75 100
1930/A G06
LT1930
LT1930A
4
LT1930/LT1930A
BLOCK DIAGRA
W
Figure 2. Block Diagram
OPERATIO
U
The LT1930 uses a constant frequency, current-mode
control scheme to provide excellent line and load regula-
tion. Operation can be best understood by referring to the
block diagram in Figure 2. At the start of each oscillator
cycle, the SR latch is set, which turns on the power switch
Q1. A voltage proportional to the switch current is added
to a stabilizing ramp and the resulting sum is fed into the
positive terminal of the PWM comparator A2. When this
voltage exceeds the level at the negative input of A2, the SR
latch is reset turning off the power switch. The level at the
negative input of A2 is set by the error amplifier A1, and is
simply an amplified version of the difference between the
feedback voltage and the reference voltage of 1.255V. In
this manner, the error amplifier sets the correct peak
current level to keep the output in regulation. If the error
amplifier’s output increases, more current is delivered to
the output; if it decreases, less current is delivered. The
LT1930 has a current limit circuit not shown in Figure 2.
The switch current is constantly monitored and not al-
lowed to exceed the maximum switch current (typically
1.2A). If the switch current reaches this value, the SR latch
is reset regardless of the state of comparator A2. This
current limit helps protect the power switch as well as the
external components connected to the LT1930.
The block diagram for the LT1930A (not shown) is iden-
tical except that the oscillator frequency is 2.2MHz.
+
+
RQ
S
0.01
SW
DRIVER
COMPARATOR
2
SHDN
4
1
V
IN
5
FB
3
+
Σ
RAMP
GENERATOR
1.255V
REFERENCE
R
C
C
C
1.2MHz
OSCILLATOR*
GND
1930/A BD
Q1
A2
A1
R1 (EXTERNAL)
R2 (EXTERNAL)
FB
V
OUT
SHUTDOWN
*2.2MHz FOR LT1930A
5
LT1930/LT1930A
APPLICATIONS INFORMATION
WUUU
LT1930 AND LT1930A DIFFERENCES
Switching Frequency
The key difference between the LT1930 and LT1930A is
the faster switching frequency of the LT1930A. At 2.2MHz,
the LT1930A switches at nearly twice the rate of the
LT1930. Care must be taken in deciding which part to use.
The high switching frequency of the LT1930A allows
smaller cheaper inductors and capacitors to be used in a
given application, but with a slight decrease in efficiency
and maximum output current when compared to the
LT1930. Generally, if efficiency and maximum output
current are critical, the LT1930 should be used. If applica-
tion size and cost are more important, the LT1930A will be
the better choice. In many applications, tiny inexpensive
chip inductors can be used with the LT1930A, reducing
solution cost.
Duty Cycle
The maximum duty cycle (DC) of the LT1930A is 75%
compared to 84% for the LT1930. The duty cycle for a
given application using the boost topology is given by:
DC VV
V
OUT IN
OUT
=||||
||
For a 5V to 12V application, the DC is 58.3% indicating that
the LT1930A could be used. A 5V to 24V application has
a DC of 79.2% making the LT1930 the right choice. The
LT1930A can still be used in applications where the DC, as
calculated above, is above 75%. However, the part must
be operated in the discontinuous conduction mode so that
the actual duty cycle is reduced.
INDUCTOR SELECTION
Several inductors that work well with the LT1930 are listed
in Table 1 and those for the LT1930A are listed in Table 2.
These tables are not complete, and there are many other
manufacturers and devices that can be used. Consult each
manufacturer for more detailed information and for their
entire selection of related parts, as many different sizes and
shapes are available. Ferrite core inductors should be used
to obtain the best efficiency, as core losses at 1.2MHz are
much lower for ferrite cores than for cheaper powdered-
iron types. Choose an inductor that can handle at least 1A
without saturating, and ensure that the inductor has a low
DCR (copper-wire resistance) to minimize I
2
R power losses.
A 4.7µH or 10µH inductor will be the best choice for most
LT1930 designs. For LT1930A designs, a 2.2µH to 4.7µH
inductor will usually suffice. Note that in some applica-
tions, the current handling requirements of the inductor
can be lower, such as in the SEPIC topology where each
inductor only carries one-half of the total switch current.
Table 1. Recommended Inductors – LT1930
MAX SIZE
L DCR L × W × H
PART (µH) m(mm) VENDOR
CDRH5D18-4R1 4.1 57 4.5 × 4.7 × 2.0 Sumida
CDRH5D18-100 10 124 (847) 956-0666
CR43-4R7 4.7 109 3.2 × 2.5 × 2.0 www.sumida.com
CR43-100 10 182
DS1608-472 4.7 60 4.5 × 6.6 × 2.9 Coilcraft
DS1608-103 10 75 (847) 639-6400
www.coilcraft.com
ELT5KT4R7M 4.7 240 5.2 × 5.2 × 1.1 Panasonic
ELT5KT6R8M 6.8 360 (408) 945-5660
www.panasonic.com
Table 2. Recommended Inductors – LT1930A
MAX SIZE
L DCR L × W × H
PART (µH) m(mm) VENDOR
LQH3C2R2M24 2.2 126 3.2 × 2.5 × 2.0 Murata
LQH3C4R7M24 4.7 195 (404) 573-4150
www.murata.com
CR43-2R2 2.2 71 4.5 × 4.0 × 3.0 Sumida
CR43-3R3 3.3 86 (847) 956-0666
www.sumida.com
1008PS-272 2.7 100 3.7 × 3.7 × 2.6 Coilcraft
1008PS-332 3.3 110 (800) 322-2645
www.coilcraft.com
ELT5KT3R3M 3.3 204 5.2 × 5.2 × 1.1 Panasonic
(408) 945-5660
www.panasonic.com
The inductors shown in Table 2 for use with the LT1930A
were chosen for small size. For better efficiency, use
similar valued inductors with a larger volume. For
example, the Sumida CR43 series in values ranging from
2.2µH to 4.7µH will give an LT1930A application a few
percentage points increase in efficiency, compared to the
smaller Murata LQH3C Series.
6
LT1930/LT1930A
APPLICATIONS INFORMATION
WUUU
CAPACITOR SELECTION
Low ESR (equivalent series resistance) capacitors should
be used at the output to minimize the output ripple voltage.
Multi-layer ceramic capacitors are an excellent choice, as
they have extremely low ESR and are available in very
small packages. X5R dielectrics are preferred, followed by
X7R, as these materials retain the capacitance over wide
voltage and temperature ranges. A 4.7µF to 10µF output
capacitor is sufficient for most applications, but systems
with very low output currents may need only a 1µF or 2.2µF
output capacitor. Solid tantalum or OSCON capacitors can
be used, but they will occupy more board area than a
ceramic and will have a higher ESR. Always use a capacitor
with a sufficient voltage rating.
Ceramic capacitors also make a good choice for the input
decoupling capacitor, which should be placed as close as
possible to the LT1930/LT1930A. A 1µF to 4.7µF input
capacitor is sufficient for most applications. Table 3 shows
a list of several ceramic capacitor manufacturers. Consult
the manufacturers for detailed information on their entire
selection of ceramic parts.
Table 3. Ceramic Capacitor Manufacturers
Taiyo Yuden (408) 573-4150 www.t-yuden.com
AVX (803) 448-9411 www.avxcorp.com
Murata (714) 852-2001 www.murata.com
The decision to use either low ESR (ceramic) capacitors or
the higher ESR (tantalum or OSCON) capacitors can affect
the stability of the overall system. The ESR of any capaci-
tor, along with the capacitance itself, contributes a zero to
the system. For the tantalum and OSCON capacitors, this
zero is located at a lower frequency due to the higher value
of the ESR, while the zero of a ceramic capacitor is at a
much higher frequency and can generally be ignored.
A phase lead zero can be intentionally introduced by
placing a capacitor (C3) in parallel with the resistor (R1)
between V
OUT
and V
FB
as shown in Figure 1. The frequency
of the zero is determined by the following equation.
ƒ=
Z
RC
1
213π••
By choosing the appropriate values for the resistor and
capacitor, the zero frequency can be designed to improve
the phase margin of the overall converter. The typical
target value for the zero frequency is between 35kHz to
55kHz. Figure 3 shows the transient response of the step-
up converter from Figure 1 without the phase lead capaci-
tor C3. The phase margin is reduced as evidenced by more
ringing in both the output voltage and inductor current. A
10pF capacitor for C3 results in better phase margin,
which is revealed in Figure 4 as a more damped response
and less overshoot. Figure 5 shows the transient response
when a 33µF tantalum capacitor with no phase lead
capacitor is used on the output. The higher output voltage
ripple is revealed in the upper waveform as a set of double
lines. The transient response is not greatly improved
which implies that the ESR zero frequency is too high to
increase the phase margin.
VOUT
0.2V/DIV
AC COUPLED
ILI
0.5A/DIV
AC COUPLED
250mA
150mA
LOAD
CURRENT
50µs/DIV 1930 F03
Figure 3. Transient Response of Figure 1's Step-Up
Converter without Phase Lead Capacitor
Figure 4. Transient Response of Figure 1's Step-Up
Converter with 10pF Phase Lead Capacitor
VOUT
0.2V/DIV
AC COUPLED
ILI
0.5A/DIV
AC COUPLED
250mA
150mA
LOAD
CURRENT
50µs/DIV 1930 F04
7
LT1930/LT1930A
Figure 5. Transient Response of Step-Up Converter with 33µF
Tantalum Output Capacitor and No Phase Lead Capacitor
VOUT
0.2V/DIV
AC COUPLED
ILI
0.5A/DIV
AC COUPLED
250mA
150mA
LOAD
CURRENT 200µs/DIV 1930 F04
DIODE SELECTION
A Schottky diode is recommended for use with the LT1930/
LT1930A. The Motorola MBR0520 is a very good choice.
Where the switch voltage exceeds 20V, use the MBR0530
(a 30V diode). Where the switch voltage exceeds 30V, use
the MBR0540 (a 40V diode). These diodes are rated to
handle an average forward current of 0.5A. In applications
where the average forward current of the diode exceeds
0.5A, a Microsemi UPS5817 rated at 1A is recommended.
SETTING OUTPUT VOLTAGE
To set the output voltage, select the values of R1 and R2
(see Figure 1) according to the following equation.
RR V
V
OUT
12
1 255 1=
.
A good value for R2 is 13.3k which sets the current in the
resistor divider chain to 1.255V/13.3k = 94.7µA.
Figure 6. Suggested Layout
R1
R2
GND C3
C2
L1
D1 C1
V
OUT
V
IN
SHUTDOWN
1930 F06
+
+
GND
V
IN
SW
SHDN FB
V
IN
16V
4
51
3
D1
L1
2
R1
LT1930
1930 F07
C2
C1 121k
R2
V
OUT
Figure 7. Keeping SHDN Below 10V
LAYOUT HINTS
The high speed operation of the LT1930/LT1930A
demands careful attention to board layout. You will not get
advertised performance with careless layout. Figure 6
shows the recommended component placement.
Driving SHDN Above 10V
The maximum voltage allowed on the SHDN pin is 10V. If
you wish to use a higher voltage, you must place a resistor
in series with SHDN. A good value is 121k. Figure 7 shows
a circuit where V
IN
= 16V and SHDN is obtained from V
IN
.
The voltage on the SHDN pin is kept below 10V.
APPLICATIONS INFORMATION
WUUU
8
LT1930/LT1930A
TYPICAL APPLICATIO S
U
Efficiency
GND
V
IN
SW
SHDN FB
4V TO 6.5V
4
51
3
D1
L1
10µH
L2
10µH
2
243k
LT1930
1930 TA02a
C1
2.2µF
4-CELL
BATTERY C2
10µF
C3
1µF
82.5k
V
OUT
5V
300mA
C1: TAIYO-YUDEN X5R LMK212BJ225MG
C2: TAIYO-YUDEN X5R JMK316BJ106ML
C3: TAIYO-YUDEN X5R LMK212BJ105MG
SHDN
D1: ON SEMICONDUCTOR MBR0520
L1, L2: MURATA LQH3C100K24
LOAD CURRENT (mA)
0
EFFICIENCY (%)
60
65
70
400 500
1930 TA02b
55
50
40 100 200 300
45
80
75
V
IN
= 6.5V
V
IN
= 4V
4-Cell to 5V SEPIC Converter
4-Cell to 5V SEPIC Converter with Coupled Inductors
GND
V
IN
SW
SHDN FB
4V TO 6.5V
4
51
3
D1
L1A
10µH
L1B
10µH
2
243k
LT1930
1930/A TA03
C1
2.2µF
4-CELL
BATTERY C2
10µF
C3
1µF
82.5k
V
OUT
5V
300mA
C1: TAIYO-YUDEN X5R LMK212BJ225MG
C2: TAIYO-YUDEN X5R JMK316BJ106ML
C3: TAIYO-YUDEN X5R LMK212BJ105MG
D1: ON SEMICONDUCTOR MBR0520
L1: SUMIDA CLS62-100
SHDN
GND
V
IN
SW
SHDN FB
V
IN
5V
4
51
3
D1
L1
10µH
2
R1
665k
LT1930
1930/A TA04
C2
2.2µF
C1
4.7µF
R2
36.5k
V
OUT
24V
90mA
C1: TAIYO-YUDEN X5R EMK316BJ475ML
C2: TAIYO-YUDEN X5R JMK212BJ475MG
D1: ON SEMICONDUCTOR MBR0530
L1: SUMIDA CR43-100
SHDN
5V to 24V Boost Converter
GND
V
IN
SW
SHDN FB
V
IN
5V
4
51
3
D1
C4
1µF
D2
L1
3.3µH
2
R1
147k
C5
1µF
LT1930
D3 D4
1930/A TA05
C2
2.2µF
C6
2.2µF
C1
2.2µF
R2
13.3k
15V
70mA
15V
70mA
C1: TAIYO-YUDEN X5R LMK212BJ225MG
C2, C3: TAIYO-YUDEN X5R EMK316BJ225ML
C4, C5: TAIYO-YUDEN X5R TMK316BJ105ML
(408) 573-4150
D1 TO D4: ON SEMICONDUCTOR MBR0520 (800) 282-9855
L1: SUMIDA CR43-3R3 (874) 956-0666
OFF ON
±15V Dual Output Converter with Output Disconnect
9
LT1930/LT1930A
TYPICAL APPLICATIO S
U
GND
V
IN
SW
SHDN FB
V
IN
3.3V
4
51
3
D1
L1
5.6µH
2
R1
40.2k
LT1930
1930/A TA07a
C2
10µF
C1
4.7µF
R2
13.3k
V
OUT
5V
480mA
C1: TAIYO-YUDEN X5R JMK212BJ475MG www.t-yuden.com
C2: TAIYO-YUDEN X5R JMK316BJ106ML
D1: ON SEMICONDUCTOR MBR0520 www.onsemi.com
L1: SUMIDA CR43-5R6 www.sumida.com
OFF ON
LOAD CURRENT (mA)
0
EFFICIENCY (%)
65
70
75
300 500
1930/A TA07b
60
55
50 100 200 400
80
85
90
V
IN
= 3.3V
V
IN
= 2.6V
Efficiency
3.3V to 5V Boost Converter
GND
V
IN
SW
SHDN FB
4
51
3
D1
M1
L1
4.7µH
2
R1
60.4k
R2
11.3k
LT1930
1930/A TA06
C1
2.2µF
V
IN
3V to 6V
C2
22µF
C3
47pF
V
OUT
8V
520mA AT V
IN
= 6V
240mA AT V
IN
= 3V
C1: TAIYO-YUDEN X5R LMK432BJ226MM
C2: TAIYO-YUDEN X5R LMK212BJ225MG
D1: ON SEMICONDUCTOR MBR0520
L1: SUMIDA CR43-4R7
M1: SILICONIX Si6433DQ
SHDN
Boost Converter with Reverse Battery Protection
GND
V
IN
SW
SHDN FB
V
IN
5V
4
51
3
D1
L1
2.2µH
2
R1
115k
LT1930A
1930/A TA08a
C2
2.2µF
C1
2.2µF
R2
13.3k
V
OUT
12V
250mA
C1: TAIYO-YUDEN X5R LMK212BJ225MG
C2: TAIYO-YUDEN X5R EMK316BJ225ML
D1: ON SEMICONDUCTOR MBR0520
L1: MURATA LQH3C2R2M24
SHDN
LOAD CURRENT (mA)
0
EFFICIENCY (%)
65
70
75
150 250
1930/A TA08b
60
55
50 50 100 200
80
85
90
300
V
IN
= 5V
V
OUT
= 12V
5V to 12V, 250mA Step-Up Converter Efficiency
10
LT1930/LT1930A
TYPICAL APPLICATIO S
U
GND
V
IN
SW
SHDN FB
V
IN
3.3V
4
51
3
D5
L1
4.7µH
2
R1
124k
LT1930
1930/A TA11a
C5
10µF
C4
1µF
C1
2.2µF
C2
0.1µF
C6
1µF
R2
20k
9V
200mA
–9V
10mA
18V
10mA
C1: X5R OR X7R, 6.3V
C2,C3, C5: X5R OR X7R, 10V
C4: X5R OR X7R, 25V
D1- D4: BAT54S OR EQUIVALENT
D5: MBR0520 OR EQUIVALENT
L1: PANASONIC ELT5KT4R7M
3.3V
0V
V
SS
D
SS
1N4148
R
SS
30k
C
SS
68nF
D1
D4
D3
D2
C3
0.1µF
+
GND
V
IN
SW
SHDN FB
V
IN
3.3V
4
51
3
D7
L1
4.7µH
2
R1
113k
LT1930
1930/A TA12a
C7
10µF
C6
1µF
C1
2.2µF
C2
0.1µF
C8
1µF
R2
21k
8V
220mA
–8V
10mA
23V
10mA
C1: X5R OR X7R, 6.3V
C2-C4, C7, C8: X5R OR X7R, 10V
C5: X5R OR X7R, 16V
C6: X5R OR X7R, 25V
D1- D6: BAT54S OR EQUIVALENT
D7: MBR0520 OR EQUIVALENT
L1: PANASONIC ELT5KT4R7M
3.3V
0V
V
SS
D
SS
1N4148
R
SS
30k
C
SS
68nF
D1
D5
D6
D2
C3
0.1µFC4
0.1µFC5
0.1µF
D3 D4
+
8V, 23V, –8V Triple Output TFT-LCD Bias Supply with Soft-Start
9V, 18V, –9V Triple Output TFT-LCD Bias Supply with Soft-Start
Start-Up Waveforms
Start-Up Waveforms
9V OUTPUT
5V/DIV
9V OUTPUT
5V/DIV
18V OUTPUT
10V/DIV
IL1 0.5A/DIV
2ms/DIV
8V OUTPUT
5V/DIV
8V OUTPUT
5V/DIV
23V OUTPUT
10V/DIV
IL1 0.5A/DIV
2ms/DIV
11
LT1930/LT1930A
U
PACKAGE DESCRIPTIO
1.50 – 1.75
(.059 – .069)
(NOTE 3)
2.60 – 3.00
(.102 – .118)
.25 – .50
(.010 – .020)
(5PLCS, NOTE 2)
L
DATUM ‘A’
.09 – .20
(.004 – .008)
(NOTE 2)
A1
S5 SOT-23 0401
PIN ONE
2.80 – 3.10
(.110 – .118)
(NOTE 3)
.95
(.037)
REF
AA2
1.90
(.074)
REF
.20
(.008)
.90 – 1.45
(.035 – .057)
SOT-23
(Original)
.00 – .15
(.00 – .006)
.90 – 1.30
(.035 – .051)
.35 – .55
(.014 – .021)
1.00 MAX
(.039 MAX)
SOT-23
(ThinSOT)
A
A1
A2
L
.01 – .10
(.0004 – .004)
.80 – .90
(.031 – .035)
.30 – .50 REF
(.012 – .019 REF)
MILLIMETERS
(INCHES)
NOTE:
1. CONTROLLING DIMENSION: MILLIMETERS
2. DIMENSIONS ARE IN
3. DRAWING NOT TO SCALE
4. DIMENSIONS ARE INCLUSIVE OF PLATING
5. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
6. MOLD FLASH SHALL NOT EXCEED .254mm
7. PACKAGE EIAJ REFERENCE IS:
SC-74A (EIAJ) FOR ORIGINAL
JEDEL MO-193 FOR THIN
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.
S5 Package
5-Lead Plastic SOT-23
(Reference LTC DWG # 05-08-1633)
(Reference LTC DWG # 05-08-1635)
12
LT1930/LT1930A
1930af LT/TP 0801 2K • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 2001
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
FAX: (408) 434-0507
www.linear.com
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
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LT1316 Burst ModeTM Operation DC/DC Converter with Programmable Current Limit 1.5V Minimum, Precise Control of Peak Current Limit
LT1317 2-Cell Micropower DC/DC Converter with Low-Battery Detector 3.3V at 200mA from 2 Cells, 600kHz Fixed Frequency
LT1610 Single Cell Micropower DC/DC Converter 3V at 30mA from 1V, 1.7MHz Fixed Frequency
LT1611 Inverting 1.4MHz Switching Regulator in 5-Lead ThinSOT 5V at 150mA from 5V Input, ThinSOT Package
LT1613 1.4MHz Switching Regulator in 5-Lead ThinSOT 5V at 200mA from 3.3V Input, ThinSOT Package
LT1615 Micropower Constant Off-Time DC/DC Converter in 5-Lead ThinSOT 20V at 12mA from 2.5V, ThinSOT Package
LT1617 Micropower Inverting DC/DC Converter in 5-Lead ThinSOT –15V at 12mA from 2.5V Input, ThinSOT Package
LT1931/LT1931A Inverting 1.2MHz/2.2MHz Switching Regulator in 5-Lead ThinSOT 5V at 350mA from 5V input, ThinSOT Package
Burst Mode is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
U
3.3V to 5V Transient Response
VOUT
50mV/DIV
AC COUPLED
ILI
0.5A/DIV
AC COUPLED
300mA
200mA
LOAD
CURRENT
20µs/DIV 1930 F03
GND
V
IN
SW
SHDN FB
V
IN
3.3V
4
51
3
D1
L1
2.2µH
2
R1
30.1k
LT1930A
1930/A TA09a
C2
10µF
C1
2.2µF
R2
10k
V
OUT
5V
450mA
C1: TAIYO-YUDEN X5R LMK212BJ225MG
C2: TAIYO-YUDEN X5R JMK316B106ML
D1: ON SEMICONDUCTOR MBR0520
L1: MURATA LQH3C2R2M24
SHDN
LOAD CURRENT (mA)
0
EFFICIENCY (%)
65
70
75
300 500
1930/A TA09b
60
55
50 100 200 400
80
85
90 V
IN
= 3.3V
V
OUT
= 5V
Efficiency
3.3V to 5V, 450mA Step-Up Converter