LT3467EDDB

LT3467/LT3467A 1.1A Step-Up DC/DC Converter with Integrated Soft-Start DESCRIPTION FEATURES n n n n n n n n n n n n n n n The LT®3467/LT3467A switching regulators combine a 42V, 1.1A switch with a soft-start function. Pin compatible with the LT1930, its low VCESAT bipolar switch enables the device to deliver high current outputs in a small footprint. The LT3467 switches at 1.3MHz, allowing the use of tiny, low cost and low height inductors and capacitors. The LT3467A switches at 2.1MHz, allowing the use of even smaller components. High inrush current at start-up is eliminated using the programmable soft-start function. A single external capacitor sets the current ramp rate. A constant frequency current mode PWM architecture results in low, predictable output noise that is easy to filter. 1.3MHz Switching Frequency (LT3467) 2.1MHz Switching Frequency (LT3467A) Low VCESAT Switch: 330mV at 1.1A High Output Voltage: Up to 40V Wide Input Range: 2.4V to 16V Dedicated Soft-Start Pin 5V at 540mA from 3.3V Input (LT3467) 5V at 430mA from 3.3V Input (LT3467A) 12V at 270mA from 5V Input (LT3467) 12V at 260mA from 5V Input (LT3467A) Uses Small Surface Mount Components Low Shutdown Current: – gmp VOUT + CPL + VC gma RC RO CC RESR COUT 1.255V REFERENCE R1 – R2 3467 F06 CC: COMPENSATION CAPACITOR COUT: OUTPUT CAPACITOR CPL: PHASE LEAD CAPACITOR gma: TRANSCONDUCTANCE AMPLIFIER INSIDE IC gmp: POWER STAGE TRANSCONDUCTANCE AMPLIFIER RC: COMPENSATION RESISTOR RL: OUTPUT RESISTANCE DEFINED AS VOUT DIVIDED BY ILOAD(MAX) RO: OUTPUT RESISTANCE OF gma R1, R2: FEEDBACK RESISTOR DIVIDER NETWORK RESR: OUTPUT CAPACITOR ESR 1 2 Phase Lead Zero: Z4 = RL Phase Lead Pole: P4 = fS 3 1 2 • π • R1• CPL 1 2 • π • CPL • R1• R2 R1+ R2 The current mode zero is a right-half plane zero which can be an issue in feedback control design, but is manageable with proper external component selection. Figure 6. Boost Converter Equivalent Model 3467afe 10 LT3467/LT3467A APPLICATIONS INFORMATION Table 3. Bode Plot Parameters PARAMETER VALUE UNITS COMMENT RL 10.4 Ω Application Specific 15 μF Application Specific 50 0 COUT 40 –45 RESR 10 mΩ Application Specific 30 –90 RO 0.4 MΩ Not Adjustable 20 –135 CC 60 pF Not Adjustable 10 –180 0 –225 –10 –270 –20 –315 –30 –360 –40 GAIN PHASE –50 100 1k PHASE (DEG) GAIN (dB) Using the circuit of Figure 2 as an example, the following table shows the parameters used to generate the Bode plot shown in Figure 7. –405 –450 1M 10k 100k FREQUENCY (Hz) 3467 F07 Figure 7. Bode Plot of 3.3V to 5V Application CPL 3.3 pF Adjustable RC 100 kΩ Not Adjustable R1 402 kΩ Adjustable R2 133 kΩ VOUT 5 V Application Specific Adjustable VIN 3.3 V Application Specific gma 35 μmho Not Adjustable gmp 7.5 mho Not Adjustable L 2.7 μH fS 1.3* MHz Application Specific Not Adjustable *2.1MHz for LT3467A From Figure 7, the phase is –138° when the gain reaches 0dB giving a phase margin of 42°. This is more than adequate. The crossover frequency is 37kHz. TYPICAL APPLICATIONS Lithium-Ion to 6V Step-Up DC/DC Converter L1 2.2μH SW VIN C1 2.2μF SHDN C4 0.047μF SHDN LT3467 SS 95 D1 R1 501k C3 1.8pF VOUT 6V 275mA AT VIN = 2.7V 490mA AT VIN = 3.8V 590mA AT VIN = 4.2V FB GND R2 133k C2 15μF 90 VIN = 4.2V 85 EFFICIENCY (%) VIN 2.7V TO 4.2V Li-Ion to 6V VIN = 3.8V VIN = 2.7V 80 75 70 65 60 C1, C2: X5R OR X7R, 6.3V D1: ON SEMICONDUCTOR MBRM120 L1: SUMIDA CR43-2R2 3467 TA02 55 50 50 100 200 300 400 IOUT (mA) 500 600 700 3467 TA02b 3467afe 11 LT3467/LT3467A TYPICAL APPLICATIONS 4-Cell to 5V SEPIC Converter C3 1μF L1 10μH 4V TO 6.5V C1 2.2μF SHDN 4-CELL BATTERY D1 VIN SW SHDN LT3467 FB SS 255k GND 84.5k C4 0.047μF VOUT 5V 325mA AT VIN = 4V 400mA AT VIN = 5V 450mA AT VIN = 6.5V C5 4.7pF L2 10μH C2 10μF D1: PHILIPS PMEG 2010 L1, L2: MURATA LQH32CN100K33L C1, C3: X5R or X7R, 10V C2: X5R or X7R, 6.3V 3467 TA03 5V to 40V Boost Converter L1 2.7μH VIN 5V C1 4.7μF SHDN D1 SW VIN SHDN LT3467 SS C3 0.1μF VOUT 40V 20mA R1 412k C2 1μF FB R2 13.3k GND C1: X5R or X7R, 6.3V C2: X5R or X7R, 50V D1: ON SEMICONDUCTOR, MBRM140 L1: SUMIDA CD43-2R7 3467 TA04a ±15V Dual Output Converter with Output Disconnect VIN 5V C4 1μF L1 10μH C1 2.2μF OFF ON SHDN LT3467 SS C6 0.047μF 15V 100mA SW VIN D1 C5 1μF R3 1Ω R1 147k D2 C2 2.2μF FB R2 13.3k GND C1: X5R or X7R, 6.3V C2 TO C5: X5R or X7R, 16V D1 TO D4: PHILIPS PMEG 2005 L1: SUMIDA CR43-100 D3 R4 1Ω D4 C3 2.2μF 3467 TA05 –15V 100mA 3467afe 12 LT3467/LT3467A TYPICAL APPLICATIONS 9V, 18V, –9V Triple Output TFT-LCD Bias Supply with Soft-Start D1 D2 C3 0.1μF L1 4.7μH VIN 3.3V C1 2.2μF VIN 9V 220mA SW 3.3V 9V OUTPUT 5V/DIV –9V OUTPUT 5V/DIV R1 124k C5 10μF FB SS 0V Start-Up Waveforms D5 SHDN LT3467 VSHDN 18V 10mA C4 1μF GND C2 0.1μF C7 0.1μF C1: X5R OR X7R, 6.3V C2,C3, C5, C6: X5R OR X7R, 10V C4: X5R OR X7R, 25V D1 TO D4: PHILIPS BAT54S OR EQUIVALENT D5: PHILIPS PMEG 2005 L1: PANASONIC ELT5KT4R7M R2 20k 18V OUTPUT 10V/DIV IL1 0.5A/DIV D4 D3 C6 1μF –9V 10mA 2ms/DIV 3467 TA06b 3467 TA06a 8V, 23V, –8V Triple Output TFT-LCD Bias Supply with Soft-Start D1 D2 D3 C3 0.1μF L1 4.7μH VIN 3.3V C1 2.2μF SHDN LT3467 SS VSHDN 3.3V 0V C4 0.1μF C5 0.1μF 23V 10mA C6 1μF Start-Up Waveforms D7 8V 270mA R1 113k SW VIN D4 C7 10μF FB GND C9 0.1μF C1: X5R OR X7R, 6.3V C2 TO C4, C7, C8: X5R OR X7R, 10V C5: X5R OR X7R, 16V C6: X5R OR X7R, 25V D1 TO D6: PHILIPS BAT54S OR EQUIVALENT D7: PHILIPS PMEG 2005 L1: PANASONIC ELT5KT4R7M 8V OUTPUT 5V/DIV –8V OUTPUT 5V/DIV C2 0.1μF R2 21k 23V OUTPUT 10V/DIV IL1 0.5A/DIV D5 D6 C8 1μF 3467 TA07a 2ms/DIV 3467 TA07b –8V 10mA 3467afe 13 LT3467/LT3467A TYPICAL APPLICATIONS Single Li-Ion Cell to 5V Boost Converter L1 0.9μH SW VIN C1 4.7μF 95 D1 R1 8.06k C4* 75pF SHDN LT3467A SS FB OFF ON C3 0.047μF VOUT 5V 600mA AT VIN = 4.2V 360mA AT VIN = 3.3V 250mA AT VIN = 2.6V C2* 22μF R2 2.67k GND 90 85 EFFICIENCY (%) VIN 2.6V TO 4.2V Efficiency 80 VIN = 3.3V VIN = 4.2V VIN = 2.6V 75 70 65 60 C1, C2: X5R OR X7R, 6.3V D1: PHILIPS PMEG 2010 L1: FDK MIPW3226D0R9M *C2 CAN BE 10μF IN A 1210 OR LARGER PACKAGE WITH THE ADDITION OF C4, OTHERWISE C4 IS OPTIONAL 3467 TA09a 55 50 50 100 150 200 250 300 350 400 450 500 IOUT (mA) 3467 TA09b 2.6V-3.3V to 5V Boost Converter L1 1.5μH SW VIN C1 4.7μF OFF ON 90 D1 VOUT 5V 430mA AT VIN = 3.3V 270mA AT VIN = 2.6V R1 8.06k C4 56pF SHDN LT3467A SS FB C3 0.047μF C2 10μF R2 2.67k GND 85 80 EFFICIENCY (%) VIN 2.6V TO 3.3V Efficiency VIN = 2.6V 75 VIN = 3.3V 70 65 60 C1, C2: X5R OR X7R, 6.3V D1: PHILIPS PMEG 2010 L1: FDK MIP3226D1R5M 3467 TA08a 55 50 50 100 150 200 250 300 350 400 450 500 IOUT (mA) 3467 TA08b 3.3V to 15V, 135mA Step-Up Converter VIN C1 4.7μF OFF ON C3 0.047μF SW C1: X5R OR X7R, 6.3V C2: X5R OR X7R, 16V D1: PHILIPS PMEG 2010 L1: SUMIDA CMD4D13-6R8MC VOUT 15V 135mA R1 16.5k SHDN LT3467A SS FB GND 90 D1 C4 68pF R2 1.5k C2 2.2μF 3467 TA10a 80 EFFICIENCY (%) L1 6.8μH VIN 3.3V Efficiency 70 60 50 40 30 20 40 60 80 100 IOUT (mA) 120 140 160 3467 TA10b 3467afe 14 LT3467/LT3467A PACKAGE DESCRIPTION DDB Package 8-Lead Plastic DFN (3mm × 2mm) (Reference LTC DWG # 05-08-1702 Rev B) 0.61 p0.05 (2 SIDES) 3.00 p0.10 (2 SIDES) R = 0.115 TYP 5 R = 0.05 TYP 0.40 p 0.10 8 0.70 p0.05 2.55 p0.05 1.15 p0.05 PACKAGE OUTLINE 0.25 p 0.05 0.50 BSC 2.20 p0.05 (2 SIDES) PIN 1 BAR TOP MARK (SEE NOTE 6) 0.200 REF RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS 2.00 p0.10 (2 SIDES) 0.56 p 0.05 (2 SIDES) 0.75 p0.05 0 – 0.05 4 0.25 p 0.05 1 PIN 1 R = 0.20 OR 0.25 s 45o CHAMFER (DDB8) DFN 0905 REV B 0.50 BSC 2.15 p0.05 (2 SIDES) BOTTOM VIEW—EXPOSED PAD NOTE: 1. DRAWING CONFORMS TO VERSION (WECD-1) IN JEDEC PACKAGE OUTLINE M0-229 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON THE TOP AND BOTTOM OF PACKAGE 3467afe 15 LT3467/LT3467A PACKAGE DESCRIPTION S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636) 0.62 MAX 2.90 BSC (NOTE 4) 0.95 REF 1.22 REF 3.85 MAX 2.62 REF 1.4 MIN 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE ID RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.45 6 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 1.90 BSC S6 TSOT-23 1005 3467afe 16 LT3467/LT3467A REVISION HISTORY (Revision history begins at Rev E) REV DATE DESCRIPTION PAGE NUMBER E 04/10 Updated Note 2 in Absolute Maximum Ratings and Electrical Characteristics 2, 3 3467afe 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. 17 LT3467/LT3467A TYPICAL APPLICATIONS L1 4.7μH C1 2.2μF VIN SHDN VOUT 12V 270mA R1 115k SW SHDN LT3467 SS C3 0.047μF Efficiency D1 C4* 22pF FB C1: X5R OR X7R, 6.3V C2: X5R OR X7R, 16V D1: PHILIPS PMEG 2010 L1: SUMIDA CR43-4R7 *OPTIONAL 85 80 C2 10μF R2 13.3k GND 90 EFFICIENCY (%) VIN 5V 75 70 65 60 3467 F08a 55 50 Figure 8. 5V to 12V, 270mA Step-Up Converter VIN OFF ON C3 0.047μF D1 SW VOUT 12V 260mA R1 115k 200 250 IOUT (mA) 300 350 3467 F08b 90 85 SHDN LT3467A SS FB GND 150 95 C4 12pF C2 10μF R2 13.3k C1: X5R OR X7R, 6.3V C2: X5R OR X7R, 16V D1: PHILIPS PMEG 2010 L1: SUMIDA CDRH4D18-3R3 3467 F09a EFFICIENCY (%) C1 4.7μF 100 Efficiency L1 3.3μH VIN 5V 50 80 75 70 65 60 55 Figure 9. 5V to 12V, 260mA Step-Up Converter 50 50 100 150 200 IOUT (mA) 250 300 3467 F09b RELATED PARTS PART NUMBER LT1615/LT1615-1 DESCRIPTION 300mA/80mA (ISW), High Efficiency Step-Up DC/DC Converter LT1618 1.5A (ISW), 1.25MHz, High Efficiency Step-Up DC/DC Converter LTC1700 No RSENSE™, 530kHz, Synchronous Step-Up DC/DC Controller LTC1871 Wide Input Range, 1MHz, No RSENSE Current Mode Boost, Flyback and SEPIC Controller 1A (ISW), 1.2MHz/2.2MHz, High Efficiency Step-Up DC/DC Converter 1.5A (ISW), 1.2MHz/2.7MHz, High Efficiency Step-Up DC/DC Converter with Soft-Start 1.5A (ISW), 1.25MHz, High Efficiency Step-Up DC/DC Converter LT1930/LT1930A LT1946/LT1946A LT1961 LTC3400/ LTC3400B LTC3401 600mA (ISW), 1.2MHz, Synchronous Step-Up DC/DC Converter LTC3402 2A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter 1A (ISW), 3MHz, Synchronous Step-Up DC/DC Converter 85mA (ISW), High Efficiency Step-Up DC/DC Converter with Integrated Schottky and PNP Disconnect No RSENSE is a trademark of Linear Technology Corporation. LT3464 COMMENTS VIN: 1V to 15V, VOUT(MAX) = 34V, IQ = 20μA, ISD < 1μA, ThinSOT Package 90% Efficiency, VIN: 1.6V to 18V, VOUT(MAX) = 35V, IQ = 1.8mA, ISD < 1μA, MS Package 95% Efficiency, VIN: 0.9V to 5V, IQ = 200μA, ISD < 10μA, MS Package 92% Efficiency, VIN: 2.5V to 36V, IQ = 250μA, ISD < 10μA, MS Package High Efficiency, VIN: 2.6V to 16V, VOUT(MAX) = 34V, IQ = 4.2mA/5.5mA, ISD < 1μA, ThinSOT Package High Efficiency, VIN: 2.45V to 16V, VOUT(MAX) = 34V, IQ = 3.2mA, ISD < 1μA, MS8 Package 90% Efficiency, VIN: 3V to 25V, VOUT(MAX) = 35V, IQ = 0.9mA, ISD < 6μA, MS8E Package 92% Efficiency, VIN: 0.85V to 5V, VOUT(MAX) = 5V, IQ = 19μA/300μA, ISD < 1μA, ThinSOT Package 97% Efficiency, VIN: 0.5V to 5V, VOUT(MAX) = 5.5V, IQ = 38μA, ISD < 1μA, MS Package 97% Efficiency, VIN: 0.5V to 5V, VOUT(MAX) = 5.5V, IQ = 38μA, ISD < 1μA, MS Package VIN: 2.3V to 10V, VOUT(MAX) = 34V, IQ = 25μA, ISD < 1μA, ThinSOT Package 3467afe 18 Linear Technology Corporation LT 0410 REV E • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 2003