Text preview for : LT1930f.pdf part of Dreambox DM500 Service diagram
Back to : Schematic_diagram_DM500.r | Home
FEATURES
s s s s s s s s s s s
LT1930/LT1930A 1A, 1.2MHz/2.2MHz, Step-Up DC/DC Converters in ThinSOT DESCRIPTIO
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.
1.2MHz Switching Frequency (LT1930) 2.2MHz Switching Frequency (LT1930A) Low VCESAT 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) ThinSOTTM Package Pin-for-Pin Compatible with the LT1613
APPLICATIO S
s s s s s s s s s
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
, LTC and LT are registered trademarks of Linear Technology Corporation ThinSOT is a trademark of Linear Technology Corporation.
TYPICAL APPLICATIO
VIN 5V C1 2.2µF SHDN 4 L1 10µH 5 VIN LT1930 SHDN GND 2 FB 3 1 SW D1
90 VOUT 12V 300mA 85 VIN = 3.3V 80
R1 113k
EFFICIENCY (%)
C3* 10pF
C2 4.7µF
75 70 65 60
R2 13.3k
C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R EMK316BJ475ML D1: ON SEMICONDUCTOR MBR0520 L1: SUMIDA CR43-100 *OPTIONAL
1930/A F01
55 50 0 200 100 300 LOAD CURRENT (mA) 400
1930 TA01
Figure 1. 5V to 12V, 300mA Step-Up DC/DC Converter
U
U
U
Efficiency
VIN = 5V
1
LT1930/LT1930A
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
TOP VIEW SW 1 GND 2 FB 3 4 SHDN 5 VIN
VIN 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
ORDER PART NUMBER LT1930ES5 LT1930AES5 S5 PART MARKING LTKS LTSQ
S5 PACKAGE 5-LEAD PLASTIC SOT-23
TJMAX = 125°C, JA = 256°C/ W
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
The q 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)
PARAMETER Minimum Operating Voltage Maximum Operating Voltage Feedback Voltage
q
CONDITIONS
MIN
LT1930 TYP 2.45
MAX 2.6 16 1.270 1.280 360 6 1 0.05 1.4 1.6 2 600 1
MIN
LT1930A TYP 2.45
MAX 2.6 16 1.270 1.280 720 8 1 0.05 2.6 2.9 2.5 600 1 0.5
UNITS V V V V nA mA µA %/V MHz MHz % A mV µA V V µA µA
1.240 1.230
1.255 120 4.2 0.01 0.01
1.240 1.230
1.255 240 5.5 0.01 0.01
FB Pin Bias Current Quiescent Current Quiescent Current in Shutdown Reference Line Regulation Switching Frequency
VFB = 1.255V VSHDN = 2.4V, Not Switching VSHDN = 0V, VIN = 3V 2.6V VIN 16V
q
q
1 0.85 84 1
1.2 90 1.2 400 0.01
1.8 1.6 75 1
2.2 90 1.2 400 0.01
Maximum Duty Cycle Switch Current Limit Switch VCESAT Switch Leakage Current SHDN Input Voltage High SHDN Input Voltage Low SHDN Pin Bias Current VSHDN = 3V VSHDN = 0V (Note 3) ISW = 1A VSW = 5V
q
2.4 0.5 16 0 32 0.1
2.4 35 0 70 0.1
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.
2
U
W
U
U
W W
W
LT1930/LT1930A TYPICAL PERFOR A CE CHARACTERISTICS
Quiescent Current
7.0 NOT SWITCHING 6.5
QUIESCENT CURRENT (mA) 1.27 SHDN PIN CURRENT (µA) 1.28
6.0 5.5 5.0 4.5 4.0 3.5 3.0 50 25 0 25 50 TEMPERATURE (°C) 75 100
1.23 1.22 50
LT1930A
FB VOLTAGE (V)
LT1930
Current Limit
1.6 1.4
0.45 0.40 0.35 0.30
CURRENT LI MIT (A)
1.2
VCESAT (V)
1.0 0.8 0.6 0.4 0.2 0 10 20 30 40 50 60 70 DUTY CYCLE (%) 80 90
FREQUENCY (MHz)
PI FU CTIO S
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 VOUT according to VOUT = 1.255V(1 + R1/R2). SHDN (Pin 4): Shutdown Pin. Tie to 2.4V or more to enable device. Ground to shut down. VIN (Pin 5): Input Supply Pin. Must be locally bypassed.
U W
1930/A G01
1930/A G04
FB Pin Voltage
90 80 70 60 50 40 30 20 10 0
25 0 25 50 TEMPERATURE (°C) 75 100
SHDN Pin Current
LT1930A
1.26 1.25 1.24
LT1930
10
0
1
2 4 3 SHDN PIN VOLTAGE (V)
5
6
1930/A G03
1930/A G02
Switch Saturation Voltage
2.5 2.3 2.1 1.9 1.7 1.5 1.3 1.1 0.9 0.7
0 0.2 0.4 0.6 0.8 SWITCH CURRENT (A) 1.0 1.2
Oscillator Frequency
LT1930A
0.25 0.20 0.15 0.10 0.05 0
LT1930
0.5 50
25
25 50 0 TEMPERATURE (°C)
75
100
1930/A G05
1930/A G06
U
U
U
3
LT1930/LT1930A
BLOCK DIAGRA
VIN 5
A1
VOUT R1 (EXTERNAL) FB R2 (EXTERNAL)
RC CC
RAMP GENERATOR
SHUTDOWN
4 SHDN
3
FB 1.2MHz OSCILLATOR* *2.2MHz FOR LT1930A
Figure 2. Block Diagram
OPERATIO
The LT1930 uses a constant frequency, current-mode control scheme to provide excellent line and load regulation. 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 allowed 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 identical except that the oscillator frequency is 2.2MHz.
4
+
W
1.255V REFERENCE
+
1 SW COMPARATOR DRIVER A2 R S Q Q1
+
0.01
2 GND
1930/A BD
U
LT1930/LT1930A
APPLICATIONS INFORMATION
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 application 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:
ELT5KT4R7M ELT5KT6R8M 4.7 6.8 240 360 5.2 × 5.2 × 1.1
|V | | VIN | DC = OUT | VOUT |
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-
U
W
U
U
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 I2R 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 applications, 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
L (µH) 4.1 10 4.7 10 4.7 10 MAX DCR m 57 124 109 182 60 75 SIZE L×W×H (mm) 4.5 × 4.7 × 2.0 3.2 × 2.5 × 2.0 4.5 × 6.6 × 2.9
PART CDRH5D18-4R1 CDRH5D18-100 CR43-4R7 CR43-100 DS1608-472 DS1608-103
VENDOR Sumida (847) 956-0666 www.sumida.com Coilcraft (847) 639-6400 www.coilcraft.com Panasonic (408) 945-5660 www.panasonic.com
Table 2. Recommended Inductors LT1930A
L (µH) 2.2 4.7 2.2 3.3 2.7 3.3 3.3 MAX DCR m 126 195 71 86 100 110 204 SIZE L×W×H (mm) 3.2 × 2.5 × 2.0
PART LQH3C2R2M24 LQH3C4R7M24 CR43-2R2 CR43-3R3 1008PS-272 1008PS-332 ELT5KT3R3M
VENDOR Murata (404) 573-4150 www.murata.com Sumida (847) 956-0666 www.sumida.com Coilcraft (800) 322-2645 www.coilcraft.com Panasonic (408) 945-5660 www.panasonic.com
4.5 × 4.0 × 3.0
3.7 × 3.7 × 2.6
5.2 × 5.2 × 1.1
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.
5
LT1930/LT1930A
APPLICATIONS INFORMATION
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 AVX Murata (408) 573-4150 (803) 448-9411 (714) 852-2001 www.t-yuden.com www.avxcorp.com 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 capacitor, 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 VOUT and VFB as shown in Figure 1. The frequency of the zero is determined by the following equation.
Z = 1 2 · R1· C 3
6
U
W
U
U
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 stepup converter from Figure 1 without the phase lead capacitor 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 LOAD 250mA CURRENT 150mA 50µs/DIV
1930 F03
Figure 3. Transient Response of Figure 1's Step-Up Converter without Phase Lead Capacitor
VOUT 0.2V/DIV AC COUPLED ILI 0.5A/DIV AC COUPLED LOAD 250mA CURRENT 150mA 50µs/DIV
1930 F04
Figure 4. Transient Response of Figure 1's Step-Up Converter with 10pF Phase Lead Capacitor
LT1930/LT1930A
APPLICATIONS INFORMATION
VOUT 0.2V/DIV AC COUPLED
ILI 0.5A/DIV AC COUPLED LOAD 250mA CURRENT 150mA 200µs/DIV
1930 F04
Figure 5. Transient Response of Step-Up Converter with 33µF Tantalum Output Capacitor and No Phase Lead Capacitor
VOUT
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.
V R1 = R2 OUT 1 1.255V
A good value for R2 is 13.3k which sets the current in the resistor divider chain to 1.255V/13.3k = 94.7µA.
VIN 16V C1 121k 4 L1 5 VIN LT1930 SHDN GND 2
1930 F07
Figure 7. Keeping SHDN Below 10V
U
W
U
U
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.
D1
L1
C1
+
VIN
+
C2 R2 SHUTDOWN
GND
R1
C3
1930 F06
Figure 6. Suggested Layout
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 VIN = 16V and SHDN is obtained from VIN. The voltage on the SHDN pin is kept below 10V.
D1 VOUT 1 SW 3 R2 R1 C2
FB
7
LT1930/LT1930A
TYPICAL APPLICATIO S
4-Cell to 5V SEPIC Converter
4V TO 6.5V 5 C1 2.2µF 4-CELL BATTERY SHDN 4 VIN LT1930 SHDN GND 2 FB 3 82.5k L1 10µH 1 SW 243k L2 10µH C2 10µF C3 1µF D1 VOUT 5V 300mA
EFFICIENCY (%)
C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R JMK316BJ106ML D1: ON SEMICONDUCTOR MBR0520 C3: TAIYO-YUDEN X5R LMK212BJ105MG L1, L2: MURATA LQH3C100K24
4-Cell to 5V SEPIC Converter with Coupled Inductors
4V TO 6.5V 5 C1 2.2µF 4-CELL BATTERY SHDN 4 VIN LT1930 SHDN GND 2 C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R JMK316BJ106ML C3: TAIYO-YUDEN X5R LMK212BJ105MG D1: ON SEMICONDUCTOR MBR0520 L1: SUMIDA CLS62-100
1930/A TA03
L1A 10µH
·
1 SW
FB
VIN 5V C1 2.2µF OFF ON 4
C1: TAIYO-YUDEN X5R LMK212BJ225MG D3 D4 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
8
U
Efficiency
80 75 VIN = 4V 70 65 60 55 50 45
1930 TA02a
VIN = 6.5V
40
0
100
200 400 300 LOAD CURRENT (mA)
500
1930 TA02b
C3 1µF
5V to 24V Boost Converter
VOUT 5V 300mA
VIN 5V C1 4.7µF L1 10µH 5 VIN LT1930 4 SHDN GND 2 C1: TAIYO-YUDEN X5R EMK316BJ475ML C2: TAIYO-YUDEN X5R JMK212BJ475MG D1: ON SEMICONDUCTOR MBR0530 L1: SUMIDA CR43-100 FB 3 R2 36.5k 1 SW R1 665k C2 2.2µF D1 VOUT 24V 90mA
D1
243k 3 82.5k
·
L1B 10µH C2 10µF
SHDN
1930/A TA04
±15V Dual Output Converter with Output Disconnect
L1 3.3µH 5 VIN LT1930 SHDN GND 2 FB 3 R2 13.3k C6 2.2µF
1930/A TA05
C4 1µF 1 SW C5 1µF D2
D1 15V 70mA R1 147k C2 2.2µF
15V 70mA
LT1930/LT1930A
TYPICAL APPLICATIO S
Boost Converter with Reverse Battery Protection
VIN 3V to 6V M1 C1 2.2µF 5 VIN LT1930 SHDN 4 SHDN GND 2 C1: TAIYO-YUDEN X5R LMK432BJ226MM C2: TAIYO-YUDEN X5R LMK212BJ225MG D1: ON SEMICONDUCTOR MBR0520 L1: SUMIDA CR43-4R7 M1: SILICONIX Si6433DQ FB 3 R2 11.3k L1 4.7µH 1 SW R1 60.4k D1 C3 47pF VOUT 8V 520mA AT VIN = 6V 240mA AT VIN = 3V
3.3V to 5V Boost Converter
VIN 3.3V C1 4.7µF OFF ON 4 L1 5.6µH 5 VIN LT1930 SHDN GND 2 FB 3 R2 13.3k 1 SW R1 40.2k C2 10µF D1
90
EFFICIENCY (%)
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
5V to 12V, 250mA Step-Up Converter
L1 2.2µH 5 C1 2.2µF SHDN 4 VIN LT1930A SHDN GND 2 C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R EMK316BJ225ML D1: ON SEMICONDUCTOR MBR0520 L1: MURATA LQH3C2R2M24 FB 3 R2 13.3k 1 SW R1 115k C2 2.2µF
90
D1
VIN 5V
EFFICIENCY (%)
U
C2 22µF
1930/A TA06
Efficiency
VOUT 5V 480mA
VIN = 3.3V
85 80 75 70 65 60 VIN = 2.6V
1930/A TA07a
55 50 0 100 200 400 300 LOAD CURRENT (mA) 500
1930/A TA07b
Efficiency
VOUT 12V 250mA
VIN = 5V VOUT = 12V
85 80 75 70 65 60
1930/A TA08a
55 50 0 50 100 200 150 LOAD CURRENT (mA) 250 300
1930/A TA08b
9
LT1930/LT1930A
TYPICAL APPLICATIO S
9V, 18V, 9V Triple Output TFT-LCD Bias Supply with Soft-Start
D1 D2 C3 0.1µF VIN 3.3V C1 2.2µF VSS 3.3V 0V CSS 68nF 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 L1 4.7µH 5 1 SW LT1930 4 SHDN GND 2 C2 0.1µF D4 D3 C6 1µF FB 3 R1 124k C5 10µF R2 20k D5 9V 200mA
9V OUTPUT 5V/DIV
+
RSS 30k DSS 1N4148
VIN
8V, 23V, 8V Triple Output TFT-LCD Bias Supply with Soft-Start
D1 C3 0.1µF L1 4.7µH 5 1 SW LT1930 4 SHDN GND CSS 68nF 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 2 C2 0.1µF D5 D6 C8 1µF FB 3 R1 113k C7 10µF R2 21k D2 C4 0.1µF D7 8V 220mA D3 C5 0.1µF D4 C6 1µF 23V 10mA
VIN 3.3V C1 2.2µF VSS 3.3V 0V
+
RSS 30k DSS 1N4148
VIN
10
U
18V 10mA C4 1µF
Start-Up Waveforms
9V OUTPUT 5V/DIV 18V OUTPUT 10V/DIV
IL1 0.5A/DIV 2ms/DIV
9V 10mA
1930/A TA11a
Start-Up Waveforms
8V OUTPUT 5V/DIV
8V OUTPUT 5V/DIV
23V OUTPUT 10V/DIV
IL1 0.5A/DIV 2ms/DIV
8V 10mA
1930/A TA12a
LT1930/LT1930A
PACKAGE DESCRIPTIO
A A1 A2 L
SOT-23 (Original) .90 1.45 (.035 .057) .00 .15 (.00 .006) .90 1.30 (.035 .051) .35 .55 (.014 .021)
SOT-23 (ThinSOT) 1.00 MAX (.039 MAX) .01 .10 (.0004 .004) .80 .90 (.031 .035) .30 .50 REF (.012 .019 REF) PIN ONE .95 (.037) REF .25 .50 (.010 .020) (5PLCS, NOTE 2) 2.60 3.00 (.102 .118) 1.50 1.75 (.059 .069) (NOTE 3)
.20 (.008) DATUM `A' A A2
L NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES)
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 representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
U
S5 Package 5-Lead Plastic SOT-23
(Reference LTC DWG # 05-08-1633) (Reference LTC DWG # 05-08-1635)
2.80 3.10 (.110 .118) (NOTE 3) .09 .20 (.004 .008) (NOTE 2) 1.90 (.074) REF A1
S5 SOT-23 0401
11
LT1930/LT1930A
TYPICAL APPLICATIO
3.3V to 5V Transient Response
VOUT 50mV/DIV AC COUPLED ILI 0.5A/DIV AC COUPLED LOAD 300mA CURRENT 200mA 20µs/DIV
1930 F03
EFFICIENCY (%)
RELATED PARTS
PART NUMBER LT1307 LT1316 LT1317 LT1610 LT1611 LT1613 LT1615 LT1617 LT1931/LT1931A DESCRIPTION Single Cell Micropower 600kHz PWM DC/DC Converter Burst Mode Operation DC/DC Converter with Programmable Current Limit 2-Cell Micropower DC/DC Converter with Low-Battery Detector Single Cell Micropower DC/DC Converter Inverting 1.4MHz Switching Regulator in 5-Lead ThinSOT 1.4MHz Switching Regulator in 5-Lead ThinSOT Micropower Constant Off-Time DC/DC Converter in 5-Lead ThinSOT Micropower Inverting DC/DC Converter in 5-Lead ThinSOT Inverting 1.2MHz/2.2MHz Switching Regulator in 5-Lead ThinSOT
TM
Burst Mode is a trademark of Linear Technology Corporation.
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
q
FAX: (408) 434-0507 q www.linear.com
U
3.3V to 5V, 450mA Step-Up Converter
VIN 3.3V C1 2.2µF SHDN 4 L1 2.2µH 5 VIN LT1930A SHDN GND 2 C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R JMK316B106ML D1: ON SEMICONDUCTOR MBR0520 L1: MURATA LQH3C2R2M24 FB 3 R2 10k 1 SW R1 30.1k C2 10µF D1 VOUT 5V 450mA
1930/A TA09a
Efficiency
90 85 80 75 70 65 60 55 50 0 100 200 400 300 LOAD CURRENT (mA) 500 VIN = 3.3V VOUT = 5V
1930/A TA09b
COMMENTS 3.3V at 75mA from Single Cell, MSOP Package 1.5V Minimum, Precise Control of Peak Current Limit 3.3V at 200mA from 2 Cells, 600kHz Fixed Frequency 3V at 30mA from 1V, 1.7MHz Fixed Frequency 5V at 150mA from 5V Input, ThinSOT Package 5V at 200mA from 3.3V Input, ThinSOT Package 20V at 12mA from 2.5V, ThinSOT Package 15V at 12mA from 2.5V Input, ThinSOT Package 5V at 350mA from 5V input, ThinSOT Package
1930af LT/TP 0801 2K · PRINTED IN USA
© LINEAR TECHNOLOGY CORPORATION 2001
This datasheet has been download from: www.datasheetcatalog.com Datasheets for electronics components.