LT1930/LT1930A 1A, 1.2MHz/2.2MHz, Step-Up DC/DC Converters in ThinSOT DESCRIPTIO U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 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. 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 U APPLICATIO S ■ ■ ■ ■ ■ ■ ■ ■ ■ 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. 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. The LT1930/LT1930A are available in the 5-lead ThinSOT package. U TYPICAL APPLICATIO VIN 5V C1 2.2µF SHDN Efficiency 90 D1 5 1 VIN SW R1 113k LT1930 4 SHDN FB 3 GND 2 VOUT 12V 300mA VIN = 5V 85 VIN = 3.3V 80 C3* 10pF C2 4.7µF R2 13.3k EFFICIENCY (%) L1 10µH 75 70 65 60 C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R EMK316BJ475ML D1: ON SEMICONDUCTOR MBR0520 L1: SUMIDA CR43-100 *OPTIONAL 1930/A F01 Figure 1. 5V to 12V, 300mA Step-Up DC/DC Converter 55 50 0 200 100 300 LOAD CURRENT (mA) 400 1930 TA01 1 LT1930/LT1930A W W W AXI U U U W PACKAGE/ORDER I FOR ATIO U ABSOLUTE RATI GS (Note 1) 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 TOP VIEW SW 1 LT1930ES5 LT1930AES5 5 VIN GND 2 4 SHDN FB 3 S5 PART MARKING S5 PACKAGE 5-LEAD PLASTIC SOT-23 LTKS LTSQ TJMAX = 125°C, θJA = 256°C/ W Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS 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) PARAMETER CONDITIONS MIN Minimum Operating Voltage LT1930 TYP MAX 2.45 2.6 Maximum Operating Voltage MIN LT1930A TYP MAX UNITS 2.45 2.6 V 16 V 1.255 1.270 1.280 V V 16 Feedback Voltage ● FB Pin Bias Current VFB = 1.255V Quiescent Current VSHDN = 2.4V, Not Switching 1.240 1.230 ● 1.255 1.270 1.280 1.240 1.230 120 360 240 720 nA 4.2 6 5.5 8 mA Quiescent Current in Shutdown VSHDN = 0V, VIN = 3V 0.01 1 0.01 1 µA Reference Line Regulation 2.6V ≤ VIN ≤ 16V 0.01 0.05 0.01 0.05 %/V 1.4 1.6 1.8 1.6 2.2 2.6 2.9 MHz MHz 75 90 1 1.2 2.5 A Switching Frequency Maximum Duty Cycle 1 0.85 1.2 ● ● 84 90 1 1.2 2 % Switch Current Limit (Note 3) Switch VCESAT ISW = 1A 400 600 400 600 mV Switch Leakage Current VSW = 5V 0.01 1 0.01 1 µA SHDN Input Voltage High 2.4 2.4 SHDN Input Voltage Low SHDN Pin Bias Current 0.5 VSHDN = 3V VSHDN = 0V 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 2 V 16 0 32 0.1 35 0 0.5 V 70 0.1 µA µA 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. LT1930/LT1930A U W TYPICAL PERFOR A CE CHARACTERISTICS Quiescent Current FB Pin Voltage 7.0 SHDN Pin Current 1.28 90 NOT SWITCHING 80 SHDN PIN CURRENT (µA) 1.27 6.0 FB VOLTAGE (V) QUIESCENT CURRENT (mA) 6.5 LT1930A 5.5 5.0 4.5 LT1930 1.26 1.25 1.24 4.0 50 40 30 LT1930 20 0 3.0 –50 0 25 50 TEMPERATURE (°C) –25 1.22 –50 100 75 –25 0 25 50 TEMPERATURE (°C) 75 –10 100 Current Limit 1.4 0.40 2.3 0.35 2.1 1.2 FREQUENCY (MHz) 2.5 0.30 VCESAT (V) 0.6 0.25 0.20 0.15 0.4 0.10 0.2 0.05 0 0 10 20 30 40 50 60 70 DUTY CYCLE (%) 80 90 2 4 3 SHDN PIN VOLTAGE (V) 5 6 Oscillator Frequency Switch Saturation Voltage 0.45 0.8 1 1930/A G03 1.6 1.0 0 1930/A G02 1930/A G01 CURRENT LI MIT (A) 60 10 1.23 3.5 LT1930A 70 LT1930A 1.9 1.7 1.5 1.3 LT1930 1.1 0.9 0.7 0 0.2 0.4 0.6 0.8 SWITCH CURRENT (A) 1930/A G04 1.0 1.2 1930/A G05 0.5 –50 –25 25 50 0 TEMPERATURE (°C) 75 100 1930/A G06 U U U PI FU CTIO S SW (Pin 1): Switch Pin. Connect inductor/diode here. Minimize trace area at this pin to reduce EMI. SHDN (Pin 4): Shutdown Pin. Tie to 2.4V or more to enable device. Ground to shut down. GND (Pin 2): Ground. Tie directly to local ground plane. VIN (Pin 5): Input Supply Pin. Must be locally bypassed. 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). 3 LT1930/LT1930A W BLOCK DIAGRA 1.255V REFERENCE VIN 5 1 SW + – A1 – DRIVER RC VOUT COMPARATOR + A2 R CC R1 (EXTERNAL) S Q1 Q + Σ FB 0.01Ω – R2 (EXTERNAL) RAMP GENERATOR SHUTDOWN 4 SHDN 3 FB 2 GND 1930/A BD 1.2MHz OSCILLATOR* *2.2MHz FOR LT1930A Figure 2. Block Diagram U 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 4 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. LT1930/LT1930A U W U U 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. 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 PART L (µH) MAX DCR mΩ SIZE L×W×H (mm) CDRH5D18-4R1 CDRH5D18-100 CR43-4R7 CR43-100 4.1 10 4.7 10 57 124 109 182 4.5 × 4.7 × 2.0 DS1608-472 DS1608-103 4.7 10 60 75 4.5 × 6.6 × 2.9 Coilcraft (847) 639-6400 www.coilcraft.com ELT5KT4R7M ELT5KT6R8M 4.7 6.8 240 360 5.2 × 5.2 × 1.1 Panasonic (408) 945-5660 www.panasonic.com 3.2 × 2.5 × 2.0 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: VENDOR Sumida (847) 956-0666 www.sumida.com Table 2. Recommended Inductors – LT1930A |V | – | VIN | DC = OUT | VOUT | MAX DCR mΩ SIZE L×W×H (mm) PART L (µH) 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. LQH3C2R2M24 LQH3C4R7M24 2.2 4.7 126 195 3.2 × 2.5 × 2.0 Murata (404) 573-4150 www.murata.com CR43-2R2 CR43-3R3 2.2 3.3 71 86 4.5 × 4.0 × 3.0 Sumida (847) 956-0666 www.sumida.com 1008PS-272 1008PS-332 2.7 3.3 100 110 3.7 × 3.7 × 2.6 Coilcraft (800) 322-2645 www.coilcraft.com INDUCTOR SELECTION ELT5KT3R3M 3.3 204 5.2 × 5.2 × 1.1 Panasonic (408) 945-5660 www.panasonic.com 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- VENDOR 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 U W U U 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 (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 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. ƒZ = 6 1 2π • R1• C 3 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 U W U U APPLICATIONS INFORMATION LAYOUT HINTS VOUT 0.2V/DIV AC COUPLED 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. 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 L1 D1 C1 + VIN VOUT DIODE SELECTION + C2 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. SHUTDOWN R2 R1 GND 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. 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. C1 D1 L1 VIN 16V VOUT 121k 5 1 VIN SW R1 LT1930 4 SHDN FB GND C2 3 R2 2 1930 F07 Figure 7. Keeping SHDN Below 10V 7 LT1930/LT1930A U TYPICAL APPLICATIO S Efficiency 4-Cell to 5V SEPIC Converter SHDN 5 1 VIN SW D1 VIN = 4V VOUT 5V 300mA 70 243k LT1930 4 SHDN FB 3 L2 10µH GND VIN = 6.5V 75 EFFICIENCY (%) C1 2.2µF 4-CELL BATTERY C3 1µF L1 10µH 4V TO 6.5V 80 C2 10µF 65 60 55 50 82.5k 2 45 C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R JMK316BJ106ML D1: ON SEMICONDUCTOR MBR0520 C3: TAIYO-YUDEN X5R LMK212BJ105MG L1, L2: MURATA LQH3C100K24 1930 TA02a 40 0 100 200 400 300 LOAD CURRENT (mA) 500 1930 TA02b 4-Cell to 5V SEPIC Converter with Coupled Inductors L1A 10µH 4V TO 6.5V C1 2.2µF 4-CELL BATTERY SHDN C3 1µF • 5 1 VIN SW 4 SHDN FB 3 GND VOUT 5V 300mA L1 10µH VIN 5V C1 4.7µF • 243k LT1930 5V to 24V Boost Converter D1 L1B 10µH C2 10µF 5 1 VIN SW 4 SHDN SHDN FB 2 C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R JMK316BJ106ML C3: TAIYO-YUDEN X5R LMK212BJ105MG D1: ON SEMICONDUCTOR MBR0520 L1: SUMIDA CLS62-100 C1: TAIYO-YUDEN X5R EMK316BJ475ML C2: TAIYO-YUDEN X5R JMK212BJ475MG D1: ON SEMICONDUCTOR MBR0530 L1: SUMIDA CR43-100 1930/A TA03 ±15V Dual Output Converter with Output Disconnect C4 1µF L1 3.3µH VIN 5V C1 2.2µF OFF ON 5 1 VIN SW 15V 70mA C5 1µF LT1930 4 SHDN D1 R1 147k D2 FB C2 2.2µF 3 GND 2 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 R2 13.3k C6 2.2µF 1930/A TA05 –15V 70mA C2 2.2µF 3 GND 82.5k VOUT 24V 90mA R1 665k LT1930 2 8 D1 R2 36.5k 1930/A TA04 LT1930/LT1930A U TYPICAL APPLICATIO S Boost Converter with Reverse Battery Protection L1 4.7µH M1 VIN 3V to 6V C1 2.2µF D1 5 1 VIN SW R1 60.4k LT1930 SHDN 4 SHDN FB VOUT 8V 520mA AT VIN = 6V 240mA AT VIN = 3V C3 47pF 3 GND 2 C2 22µF R2 11.3k C1: TAIYO-YUDEN X5R LMK432BJ226MM C2: TAIYO-YUDEN X5R LMK212BJ225MG D1: ON SEMICONDUCTOR MBR0520 L1: SUMIDA CR43-4R7 M1: SILICONIX Si6433DQ 1930/A TA06 Efficiency 3.3V to 5V Boost Converter VIN 3.3V C1 4.7µF OFF ON 90 D1 5 1 VIN SW VOUT 5V 480mA SHDN FB 80 R1 40.2k LT1930 4 C2 10µF 3 R2 13.3k GND 2 VIN = 3.3V 85 EFFICIENCY (%) L1 5.6µH VIN = 2.6V 75 70 65 60 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 1930/A TA07a 55 50 0 100 200 400 300 LOAD CURRENT (mA) 500 1930/A TA07b 5V to 12V, 250mA Step-Up Converter 90 C1 2.2µF SHDN D1 5 1 VIN SW R1 115k LT1930A 4 SHDN FB VOUT 12V 250mA C2 2.2µF 3 GND 2 C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R EMK316BJ225ML D1: ON SEMICONDUCTOR MBR0520 L1: MURATA LQH3C2R2M24 R2 13.3k VIN = 5V VOUT = 12V 85 80 EFFICIENCY (%) L1 2.2µH VIN 5V Efficiency 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 U TYPICAL APPLICATIO S 9V, 18V, –9V Triple Output TFT-LCD Bias Supply with Soft-Start D1 D2 18V 10mA C4 1µF C3 0.1µF L1 4.7µH VIN 3.3V C1 2.2µF 5 + RSS 30k VSS LT1930 4 SHDN FB C5 10µF 3 GND 0V 2 CSS 68nF 9V OUTPUT 5V/DIV R1 124k SW DSS 1N4148 3.3V 9V 200mA 1 VIN Start-Up Waveforms D5 C2 0.1µF 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 –9V OUTPUT 5V/DIV R2 20k 18V OUTPUT 10V/DIV D4 IL1 0.5A/DIV C6 1µF D3 2ms/DIV –9V 10mA 1930/A TA11a 8V, 23V, –8V Triple Output TFT-LCD Bias Supply with Soft-Start D1 D2 C3 0.1µF C1 2.2µF VSS 3.3V 5 + RSS 30k DSS 1N4148 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 FB 2 8V OUTPUT 5V/DIV R1 113k –8V OUTPUT 5V/DIV C7 10µF 3 GND CSS 68nF Start-Up Waveforms 8V 220mA SW SHDN 23V 10mA D7 LT1930 4 D4 C6 1µF C5 0.1µF 1 VIN 0V 10 C4 0.1µF L1 4.7µH VIN 3.3V D3 C2 0.1µF R2 21k 23V OUTPUT 10V/DIV IL1 0.5A/DIV D5 D6 C8 1µF 2ms/DIV –8V 10mA 1930/A TA12a LT1930/LT1930A U PACKAGE DESCRIPTIO 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) A SOT-23 (Original) .90 – 1.45 (.035 – .057) SOT-23 (ThinSOT) 1.00 MAX (.039 MAX) A1 .00 – .15 (.00 – .006) .01 – .10 (.0004 – .004) A2 .90 – 1.30 (.035 – .051) .80 – .90 (.031 – .035) L .35 – .55 (.014 – .021) .30 – .50 REF (.012 – .019 REF) 2.60 – 3.00 (.102 – .118) 1.50 – 1.75 (.059 – .069) (NOTE 3) PIN ONE .95 (.037) REF .25 – .50 (.010 – .020) (5PLCS, NOTE 2) .20 (.008) A DATUM ‘A’ L NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) .09 – .20 (.004 – .008) (NOTE 2) A2 1.90 (.074) REF A1 S5 SOT-23 0401 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. 11 LT1930/LT1930A U TYPICAL APPLICATIO 3.3V to 5V, 450mA Step-Up Converter L1 2.2µH VIN 3.3V C1 2.2µF SHDN D1 5 1 VIN SW R1 30.1k LT1930A 4 SHDN FB VOUT 5V 450mA C2 10µF 3 GND 2 R2 10k C1: TAIYO-YUDEN X5R LMK212BJ225MG C2: TAIYO-YUDEN X5R JMK316B106ML D1: ON SEMICONDUCTOR MBR0520 L1: MURATA LQH3C2R2M24 1930/A TA09a Efficiency 90 3.3V to 5V Transient Response VIN = 3.3V VOUT = 5V 85 80 EFFICIENCY (%) VOUT 50mV/DIV AC COUPLED ILI 0.5A/DIV AC COUPLED LOAD 300mA CURRENT 200mA 75 70 65 60 55 20µs/DIV 1930 F03 50 0 100 200 400 300 LOAD CURRENT (mA) 500 1930/A TA09b RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1307 Single Cell Micropower 600kHz PWM DC/DC Converter 3.3V at 75mA from Single Cell, MSOP Package TM LT1316 Burst Mode 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. 12 Linear Technology Corporation 1930af LT/TP 0801 2K • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2001