650 kHz /1.3 MHz Step-Up PWM DC-to-DC Switching Converters ADP1612/ADP1613 FEATURES TYPICAL APPLICATION CIRCUIT L1 ADP1612/ ADP1613 VIN 6 VIN 3 EN 7 FREQ 8 SS D1 ON OFF CIN R1 FB 2 1.3MHz 650kHz (DEFAULT) CSS VOUT SW 5 R2 COMP 1 GND RCOMP 4 COUT CCOMP 06772-001 Current limit 1.4 A for the ADP1612 2.0 A for the ADP 1613 Minimum input voltage 1.8 V for the ADP1612 2.5 V for the ADP1613 Pin-selectable 650 kHz or 1.3 MHz PWM frequency Adjustable output voltage up to 20 V Adjustable soft start Undervoltage lockout Thermal shutdown 8-lead MSOP Figure 1. Step-Up Regulator Configuration APPLICATIONS TFT LCD bias supplies Portable applications Industrial/instrumentation equipment 100 GENERAL DESCRIPTION 80 70 60 50 ADP1612, ADP1612, ADP1613, ADP1613, 40 V OUT = 12V V OUT = 15V V OUT = 12V V OUT = 15V 30 1 10 100 LOAD CURRENT (mA) 1k 06772-009 The ADP1612/ADP1613 operate in current mode pulse-width modulation (PWM) with up to 94% efficiency. Adjustable soft start prevents inrush currents when the part is enabled. The pin-selectable switching frequency and PWM current-mode architecture allow for excellent transient response, easy noise filtering, and the use of small, cost-saving external inductors and capacitors. Other key features include undervoltage lockout (UVLO), thermal shutdown (TSD), and logic controlled enable. VIN = 5V fSW = 1.3MHz TA = 25°C 90 EFFICIENCY (%) The ADP1612/ADP1613 are step-up dc-to-dc switching converters with an integrated power switch capable of providing an output voltage as high as 20 V. With a package height of less than 1.1 mm, the ADP1612/ADP1613 are optimal for spaceconstrained applications such as portable devices or thin film transistor (TFT) liquid crystal displays (LCDs). Figure 2. ADP1612/ADP1613 Efficiency for Various Output Voltages The ADP1612/ADP1613 are available in the lead-free 8-lead MSOP. Rev. A Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©2009 Analog Devices, Inc. All rights reserved. ADP1612/ADP1613 TABLE OF CONTENTS Features .............................................................................................. 1 UnderVoltage Lockout (UVLO) ............................................... 12 Applications ....................................................................................... 1 Enable/Shutdown Control ........................................................ 12 Typical Application Circuit ............................................................. 1 Applications Information .............................................................. 13 General Description ......................................................................... 1 Setting the Output Voltage ........................................................ 13 Revision History ............................................................................... 2 Inductor Selection ...................................................................... 13 Specifications..................................................................................... 3 Choosing the Input and Output Capacitors ........................... 13 Absolute Maximum Ratings............................................................ 4 Diode Selection........................................................................... 14 Thermal Resistance ...................................................................... 4 Loop Compensation .................................................................. 14 Boundary Condition .................................................................... 4 Soft Start Capacitor .................................................................... 15 ESD Caution .................................................................................. 4 Typical Application Circuits ......................................................... 16 Pin Configuration and Function Descriptions ............................. 5 Step-Up Regulator ...................................................................... 16 Typical Performance Characteristics ............................................. 6 Step-Up Regulator Circuit Examples ....................................... 16 Theory of Operation ...................................................................... 11 SEPIC Converter ........................................................................ 22 Current-Mode PWM Operation .............................................. 11 TFT LCD Bias Supply ................................................................ 22 Frequency Selection ................................................................... 11 PCB Layout Guidelines .................................................................. 24 Soft Start ...................................................................................... 11 Outline Dimensions ....................................................................... 25 Thermal Shutdown (TSD)......................................................... 12 Ordering Guide .......................................................................... 25 REVISION HISTORY 9/09—Rev. 0 to Rev. A Changes to Figure 45 ...................................................................... 17 Changes to Figure 48 and Figure 51 ............................................. 18 Changes to Figure 54 and Figure 57 ............................................. 19 Changes to Figure 60 and Figure 63 ............................................. 20 Changes to Figure 66 and Figure 69 ............................................. 21 Changes to Figure 72 ...................................................................... 22 Changes to Ordering Guide .......................................................... 25 4/09—Revision 0: Initial Version Rev. A | Page 2 of 28 ADP1612/ADP1613 SPECIFICATIONS VIN = 3.6 V, unless otherwise noted. Minimum and maximum values are guaranteed for TJ = −40°C to +125°C. Typical values specified are at TJ = 25°C. All limits at temperature extremes are guaranteed by correlation and characterization using standard statistical quality control (SQC), unless otherwise noted. Table 1. Parameter SUPPLY Input Voltage Quiescent Current Nonswitching State Shutdown Switching State 1 Enable Pin Bias Current OUTPUT Output Voltage Load Regulation REFERENCE Feedback Voltage Line Regulation ERROR AMPLIFIER Transconductance Voltage Gain FB Pin Bias Current SWITCH SW On Resistance SW Leakage Current Peak Current Limit 2 OSCILLATOR Oscillator Frequency Maximum Duty Cycle FREQ Pin Current EN/FREQ LOGIC THRESHOLD Input Voltage Low Input Voltage High SOFT START SS Charging Current SS Voltage UNDERVOLTAGE LOCKOUT (UVLO) Undervoltage Lockout Threshold Symbol Conditions Min VIN ADP1612 ADP1613 1.8 2.5 IQ VFB = 1.5 V, FREQ = VIN VFB = 1.5 V, FREQ = GND VEN = 0 V FREQ = VIN, no load FREQ = GND, no load VEN = 3.6 V IQSHDN IQSW IEN Max Unit 5.5 5.5 V V 1350 1300 2 5.8 4 7 μA μA μA mA mA μA 20 V mV/mA 1.2659 0.24 V %/V VFB = 1.3 V 80 60 1 50 μA/V dB nA ISW = 1.0 A VSW = 20 V ADP1612, duty cycle = 70% ADP1613, duty cycle = 70% 130 0.01 1.4 2.0 300 10 1.9 2.5 mΩ μA A A 650 1.3 90 5 720 1.4 kHz MHz % μA VOUT 900 700 0.01 4 2.2 3.3 VIN ILOAD = 10 mA to 150 mA, VIN = 3.3 V, VOUT = 12 V VFB 0.1 1.2041 ADP1612, VIN = 1.8 V to 5.5 V; ADP1613, VIN = 2.5 V to 5.5 V GMEA AV RDSON ICL fSW DMAX IFREQ ΔI = 4 μA FREQ = GND FREQ = VIN COMP = open, VFB = 1 V, FREQ = VIN FREQ = 3.6 V ADP1612, VIN = 1.8 V to 5.5 V; ADP1613, VIN = 2.5 V to 5.5 V VIL VIH ISS VSS 0.9 1.3 500 1.1 88 2 1.235 0.07 8 0.3 V V 6.2 μA V 1.6 VSS = 0 V VFB = 1.3 V 3.4 ADP1612, VIN rising ADP1612, VIN falling ADP1613, VIN rising ADP1613, VIN falling THERMAL SHUTDOWN Thermal Shutdown Threshold Thermal Shutdown Hysteresis 1 Typ This parameter specifies the average current while switching internally and with SW (Pin 5) floating. Current limit is a function of duty cycle. See the Typical Performance Characteristics section for typical values over operating ranges. Rev. A | Page 3 of 28 5 1.2 1.70 1.62 2.25 2.16 V V V V 150 20 °C °C ADP1612/ADP1613 ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Table 2. Parameter VIN, EN, FB to GND FREQ to GND COMP to GND SS to GND SW to GND Operating Junction Temperature Range Storage Temperature Range Soldering Conditions ESD (Electrostatic Discharge) Human Body Model Junction-to-ambient thermal resistance (θJA) of the package is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. The junction-toambient thermal resistance is highly dependent on the application and board layout. In applications where high maximum power dissipation exists, attention to thermal board design is required. The value of θJA may vary, depending on PCB material, layout, and environmental conditions. Rating −0.3 V to +6 V −0.3 V to VIN + 0.3 V 1.0 V to 1.6 V −0.3 V to +1.3 V 21 V −40°C to +125°C −65°C to +150°C JEDEC J-STD-020 Table 3. ±5 kV Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Absolute maximum ratings apply individually only, not in combination. Package Type 8-Lead MSOP 2-Layer Board1 4-Layer Board1 1 θJA θJC Unit 206.9 162.2 44.22 44.22 °C/W °C/W Thermal numbers per JEDEC standard JESD 51-7. BOUNDARY CONDITION Modeled under natural convection cooling at 25°C ambient temperature, JESD 51-7, and 1 W power input with 2- and 4-layer boards. ESD CAUTION Rev. A | Page 4 of 28 ADP1612/ADP1613 COMP 1 FB 2 EN 3 GND 4 ADP1612/ ADP1613 TOP VIEW (Not to Scale) 8 SS 7 FREQ 6 VIN 5 SW 06772-002 PIN CONFIGURATION AND FUNCTION DESCRIPTIONS Figure 3. Pin Configuration Table 4. Pin Function Descriptions Pin No. 1 2 Mnemonic COMP FB 3 4 5 EN GND SW 6 VIN 7 FREQ 8 SS Description Compensation Input. Connect a series resistor-capacitor network from COMP to GND to compensate the regulator. Output Voltage Feedback Input. Connect a resistive voltage divider from the output voltage to FB to set the regulator output voltage. Enable Input. Drive EN low to shut down the regulator; drive EN high to turn on the regulator. Ground. Switching Output. Connect the power inductor from the input voltage to SW and connect the external rectifier from SW to the output voltage to complete the step-up converter. Main Power Supply Input. VIN powers the ADP1612/ADP1613 internal circuitry. Connect VIN to the input source voltage. Bypass VIN to GND with a 10 μF or greater capacitor as close to the ADP1612/ADP1613 as possible. Frequency Setting Input. FREQ controls the switching frequency. Connect FREQ to GND to program the oscillator to 650 kHz, or connect FREQ to VIN to program it to 1.3 MHz. If FREQ is left floating, the part defaults to 650 kHz. Soft Start Timing Capacitor Input. A capacitor connected from SS to GND brings up the output slowly at powerup and reduces inrush current. Rev. A | Page 5 of 28 ADP1612/ADP1613 TYPICAL PERFORMANCE CHARACTERISTICS VEN = VIN and TA = 25°C, unless otherwise noted. 100 100 ADP1612 VIN = 3.3V fSW = 650kHz TA = 25°C 90 80 EFFICIENCY (%) 70 60 50 VOUT = 5V VOUT = 12V VOUT = 15V 40 30 1 10 100 LOAD CURRENT (mA) 1k 1 Figure 4. ADP1612 Efficiency vs. Load Current, VIN = 3.3 V, fSW = 650 kHz 10 100 LOAD CURRENT (mA) 1k Figure 7. ADP1612 Efficiency vs. Load Current, VIN = 5 V, fSW = 1.3 MHz 100 100 ADP1612 VIN = 3.3V fSW = 1.3MHz TA = 25°C 90 ADP1613 VIN = 5V fSW = 650kHz TA = 25°C 90 80 EFFICIENCY (%) 80 70 60 50 70 60 50 VOUT = 5V VOUT = 12V VOUT = 15V 30 1 10 100 LOAD CURRENT (mA) VOUT = 12V VOUT = 15V VOUT = 20V 40 1k 30 06772-026 40 1 Figure 5. ADP1612 Efficiency vs. Load Current, VIN = 3.3 V, fSW = 1.3 MHz 10 100 LOAD CURRENT (mA) 1k 06772-029 EFFICIENCY (%) VOUT = 12V VOUT = 15V 30 06772-012 40 Figure 8. ADP1613 Efficiency vs. Load Current, VIN = 5 V, fSW = 650 kHz 100 100 ADP1612 VIN = 5V fSW = 650kHz TA = 25°C 90 ADP1613 VIN = 5V fSW = 1.3MHz TA = 25°C 90 80 EFFICIENCY (%) 80 EFFICIENCY (%) 60 06772-028 50 70 70 60 50 70 60 50 40 10 100 LOAD CURRENT (mA) 1k 30 06772-027 30 1 VOUT = 12V VOUT = 15V VOUT = 20V 40 VOUT = 12V VOUT = 15V Figure 6. ADP1612 Efficiency vs. Load Current, VIN = 5 V, fSW = 650 kHz 1 10 100 LOAD CURRENT (mA) 1k 06772-030 EFFICIENCY (%) 80 ADP1612 VIN = 5V fSW = 1.3MHz TA = 25°C 90 Figure 9. ADP1613 Efficiency vs. Load Current, VIN = 5 V, fSW = 1.3 MHz Rev. A | Page 6 of 28 ADP1612/ADP1613 2.4 3.4 ADP1613 ADP1612 3.2 TA = +25°C 1.8 TA = –40°C 1.6 1.4 1.2 1.8 TA = +85°C 2.3 3.0 TA = +25°C 2.8 2.6 2.4 2.2 2.8 3.3 3.8 INPUT VOLTAGE (V) 4.3 4.8 Figure 10. ADP1612 Switch Current Limit vs. Input Voltage, VOUT = 5 V 2.0 2.5 3.0 3.5 4.0 INPUT VOLTAGE (V) 4.5 Figure 13. ADP1613 Switch Current Limit vs. Input Voltage, VOUT = 5 V 2.6 2.0 ADP1613 ADP1612 1.8 2.4 CURRENT LIMIT (A) CURRENT LIMIT (A) TA = –40°C TA = +85°C 06772-031 CURRENT LIMIT (A) 2.0 06772-010 CURRENT LIMIT (A) 2.2 TA = +25°C 1.6 1.4 TA = +25°C 2.2 TA = –40°C 2.0 TA = –40°C TA = +85°C 1.2 2.3 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 5.3 1.8 2.5 06772-013 1.0 1.8 Figure 11. ADP1612 Switch Current Limit vs. Input Voltage, VOUT = 8 V 3.0 3.5 4.0 4.5 5.0 5.5 INPUT VOLTAGE (V) 06772-032 TA = +85°C Figure 14. ADP1613 Switch Current Limit vs. Input Voltage, VOUT = 8 V 1.6 2.6 ADP1613 ADP1612 2.4 1.2 TA = +85°C 1.0 TA = –40°C 2.2 2.0 1.8 TA = +25°C TA = +85°C 1.6 2.3 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 5.3 1.4 2.5 06772-011 0.8 1.8 Figure 12. ADP1612 Switch Current Limit vs. Input Voltage, VOUT = 15 V 3.0 3.5 4.0 4.5 INPUT VOLTAGE (V) 5.0 5.5 06772-033 TA = –40°C TA = +25°C CURRENT LIMIT (A) CURRENT LIMIT (A) 1.4 Figure 15. ADP1613 Switch Current Limit vs. Input Voltage, VOUT = 15 V Rev. A | Page 7 of 28 ADP1612/ADP1613 800 6 ADP1612/ADP1613 ADP1612/ADP1613 750 TA = +25°C QUIESCENT CURRENT (mA) QUIESCENT CURRENT (µA) 5 700 650 TA = +125°C 600 550 TA = –40°C TA = +25°C 500 TA = +125°C 4 TA = –40°C 3 2 2.3 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 5.3 1 1.8 06772-014 400 1.8 Figure 16. ADP1612/ADP1613 Quiescent Current vs. Input Voltage, Nonswitching, fSW = 650 kHz 2.3 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 06772-018 450 5.3 Figure 19. ADP1612/ADP1613 Quiescent Current vs. Input Voltage, Switching, fSW = 1.3 MHz 800 250 ISW = 1A ADP1612/ADP1613 ADP1612/ADP1613 230 210 700 TA = +30°C 190 TA = +125°C RDSON (mΩ) QUIESCENT CURRENT (µA) 750 650 TA = +85°C 170 150 130 600 TA = –40°C 110 TA = +25°C 550 90 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 5.3 06772-017 2.3 70 1.8 Figure 17. ADP1612/ADP1613 Quiescent Current vs. Input Voltage, Nonswitching, fSW = 1.3 MHz 2.3 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 06772-016 TA = –40°C 500 1.8 5.3 Figure 20. ADP1612/ADP1613 On Resistance vs. Input Voltage 3.5 250 ISW = 1A ADP1612/ADP1613 ADP1612/ADP1613 230 VIN = 1.8V 210 TA = +25°C 190 2.5 RDSON (mΩ) QUIESCENT CURRENT (mA) 3.0 TA = +125°C 2.0 TA = –40°C 170 VIN = 2.5V 150 130 110 1.5 VIN = 3.6V 90 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 5.3 70 –40 06772-015 2.3 Figure 18. ADP1612/ADP1613 Quiescent Current vs. Input Voltage, Switching, fSW = 650 kHz Rev. A | Page 8 of 28 –15 10 35 TEMPERATURE (°C) 60 85 Figure 21. ADP1612/ADP1613 On Resistance vs. Temperature 06772-019 VIN = 5.5V 1.0 1.8 ADP1612/ADP1613 660 5.1 ADP1612/ADP1613 ADP1612/ADP1613 650 5.0 TA = +25°C VIN = 1.8V SS PIN CURRENT (µA) FREQUENCY (kHz) 640 630 620 TA = +125°C 610 4.9 VIN = 5.5V 4.8 VIN = 3.6V 4.7 600 4.6 590 2.3 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 5.3 4.5 –40 06772-020 580 1.8 Figure 22. ADP1612/ADP1613 Frequency vs. Input Voltage, fSW = 650 kHz 80 110 92.8 ADP1612/ADP1613 ADP1612/ADP1613 TA = +25°C 1.30 92.6 MAXIMUM DUTY CYCLE (%) 1.28 1.26 1.24 TA = –40°C 1.22 1.20 1.18 TA = +125°C TA = +125°C 92.4 TA = +25°C 92.2 92.0 TA = –40°C 91.8 91.6 2.3 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 5.3 91.2 1.8 06772-023 1.14 1.8 Figure 23. ADP1612/ADP1613 Frequency vs. Input Voltage, fSW = 1.3 MHz 2.3 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 5.3 06772-022 91.4 1.16 Figure 26. ADP1612/ADP1613 Maximum Duty Cycle vs. Input Voltage, fSW = 650 kHz 93.4 7 ADP1612/ADP1613 ADP1612/ADP1613 TA = +125°C 93.2 MAXIMUM DUTY CYCLE (%) 6 TA = +125°C 5 4 3 2 TA = +25°C 1 TA = –40°C 1.0 1.5 2.0 2.5 3.0 3.5 EN PIN VOLTAGE (V) 4.0 4.5 5.0 5.5 92.6 TA = –40°C 92.4 92.2 92.0 Figure 24. ADP1612/ADP1613 EN Pin Current vs. EN Pin Voltage 91.6 1.8 06772-021 0.5 92.8 91.8 0 0 TA = +25°C 93.0 2.3 2.8 3.3 3.8 4.3 INPUT VOLTAGE (V) 4.8 5.3 06772-025 FREQUENCY (MHz) 20 50 TEMPERATURE (°C) Figure 25. ADP1612/ADP1613 SS Pin Current vs. Temperature 1.32 EN PIN CURRENT (µA) –10 06772-024 TA = –40°C Figure 27. ADP1612/ADP1613 Maximum Duty Cycle vs. Input Voltage, fSW = 1.3 MHz Rev. A | Page 9 of 28 ADP1612/ADP1613 T T OUTPUT VOLTAGE (5V/DIV) OUTPUT VOLTAGE (5V/DIV) VIN = 5V VOUT = 12V ILOAD = 20mA L = 6.8µH fSW = 1.3MHz COUT = 10µF INDUCTOR CURRENT (200mA/DIV) SWITCH VOLTAGE (10V/DIV) VIN = 5V VOUT = 12V ILOAD = 250mA L = 6.8µH fSW = 1.3MHz INDUCTOR CURRENT (2A/DIV) SWITCH VOLTAGE (10V/DIV) TIME (400ns/DIV) TIME (20ms/DIV) Figure 28. ADP1612/ADP1613 Switching Waveform in Discontinuous Conduction Mode Figure 31. ADP1612/ADP1613 Start-Up from VIN, CSS =100 nF T T OUTPUT VOLTAGE (5V/DIV) INDUCTOR CURRENT (500mA/DIV) 06772-037 06772-034 EN PIN VOLTAGE (5V/DIV) OUTPUT VOLTAGE (5V/DIV) VIN = 5V VOUT = 12V ILOAD = 200mA L = 6.8µH fSW = 1.3MHz COUT = 10µF SWITCH VOLTAGE (10V/DIV) VIN = 5V VOUT = 12V ILOAD = 250mA L = 6.8µH fSW = 1.3MHz SWITCH VOLTAGE (10V/DIV) 06772-035 EN PIN VOLTAGE (5V/DIV) TIME (400ns/DIV) Figure 29. ADP1612/ADP1613 Switching Waveform in Continuous Conduction Mode TIME (400µs/DIV) 06772-038 INDUCTOR CURRENT (500mA/DIV) Figure 32. ADP1612/ADP1613 Start-Up from Shutdown, CSS = 33 nF T T OUTPUT VOLTAGE (5V/DIV) SWITCH VOLTAGE (10V/DIV) VIN = 5V VOUT = 12V ILOAD = 250mA L = 6.8µH fSW = 1.3MHz SWITCH VOLTAGE (10V/DIV) INDUCTOR CURRENT (500mA/DIV) EN PIN VOLTAGE (5V/DIV) EN PIN VOLTAGE (5V/DIV) TIME (20ms/DIV) 06772-036 INDUCTOR CURRENT (2A/DIV) Figure 30. ADP1612/ADP1613 Start-Up from VIN, CSS =33 nF TIME (400µs/DIV) 06772-039 OUTPUT VOLTAGE (5V/DIV) VIN = 5V VOUT = 12V ILOAD = 250mA L = 6.8µH fSW = 1.3MHz Figure 33. ADP1612/ADP1613 Start-Up from Shutdown, CSS = 100 nF Rev. A | Page 10 of 28 ADP1612/ADP1613 THEORY OF OPERATION L1 VIN >1.6V CIN <0.3V VIN 6 7 + VIN D COMPARATOR VOUT R1 ERROR AMPLIFIER FB VOUT DREF 5µA DRIVER VIN S Q UVLOREF VSS N1 R TSD COMPARATOR 5µA 8 D1 COUT UVLO COMPARATOR RCOMP SS SW OSCILLATOR 1 CCOMP 5 CURRENT SENSING PWM COMPARATOR VBG COMP A + 2 R2 FREQ TSENSE SOFT START BG RESET TREF BAND GAP CSS AGND 1.1MΩ ADP1612/AD1613 AGND 4 GND >1.6V <0.3V 06772-003 EN 3 Figure 34. Block Diagram with Step-Up Regulator Application Circuit The ADP1612/ADP1613 current-mode step-up switching converters boost a 1.8 V to 5.5 V input voltage to an output voltage as high as 20 V. The internal switch allows a high output current, and the high 650 kHz/1.3 MHz switching frequency allows for the use of tiny external components. The switch current is monitored on a pulse-by-pulse basis to limit it to 1.4 A typical (ADP1612) or 2.0 A typical (ADP1613). FREQUENCY SELECTION CURRENT-MODE PWM OPERATION The ADP1612/ADP1613 utilize a current-mode PWM control scheme to regulate the output voltage over all load conditions. The output voltage is monitored at FB through a resistive voltage divider. The voltage at FB is compared to the internal 1.235 V reference by the internal transconductance error amplifier to create an error voltage at COMP. The switch current is internally measured and added to the stabilizing ramp. The resulting sum is compared to the error voltage at COMP to control the PWM modulator. This current-mode regulation system allows fast transient response, while maintaining a stable output voltage. By selecting the proper resistor-capacitor network from COMP to GND, the regulator response is optimized for a wide range of input voltages, output voltages, and load conditions. The frequency of the ADP1612/ADP1613 is pin-selectable to operate at either 650 kHz to optimize the regulator for high efficiency or at 1.3 MHz for use with small external components. If FREQ is left floating, the part defaults to 650 kHz. Connect FREQ to GND for 650 kHz operation or connect FREQ to VIN for 1.3 MHz operation. When connected to VIN for 1.3 MHz operation, an additional 5 μA, typical, of quiescent current is active. This current is turned off when the part is shutdown. SOFT START To prevent input inrush current to the converter when the part is enabled, connect a capacitor from SS to GND to set the soft start period. Once the ADP1612/ADP1613 are turned on, SS sources 5 μA, typical, to the soft start capacitor (CSS) until it reaches 1.2 V at startup. As the soft start capacitor charges, it limits the peak current allowed by the part. By slowly charging the soft start capacitor, the input current ramps slowly to prevent it from overshooting excessively at startup. When the ADP1612/ ADP1613 are in shutdown mode (EN ≤ 0.3 V), a thermal shutdown event occurs, or the input voltage is below the falling undervoltage lockout voltage, SS is internally shorted to GND to discharge the soft start capacitor. Rev. A | Page 11 of 28 ADP1612/ADP1613 THERMAL SHUTDOWN (TSD) ENABLE/SHUTDOWN CONTROL The ADP1612/ADP1613 include TSD protection. If the die temperature exceeds 150°C (typical), TSD turns off the NMOS power device, significantly reducing power dissipation in the device and preventing output voltage regulation. The NMOS power device remains off until the die temperature reduces to 130°C (typical). The soft start capacitor is discharged during TSD to ensure low output voltage overshoot and inrush currents when regulation resumes. The EN input turns the ADP1612/ADP1613 regulator on or off. Drive EN low to turn off the regulator and reduce the input current to 0.01 μA, typical. Drive EN high to turn on the regulator. UNDERVOLTAGE LOCKOUT (UVLO) If the input voltage is below the UVLO threshold, the ADP1612/ ADP1613 automatically turn off the power switch and place the part into a low power consumption mode. This prevents potentially erratic operation at low input voltages and prevents the power device from turning on when the control circuitry cannot operate it. The UVLO levels have ~100 mV of hysteresis to ensure glitch free startup. When the step-up dc-to-dc switching converter is in shutdown mode (EN ≤ 0.3 V), there is a dc path from the input to the output through the inductor and output rectifier. This causes the output voltage to remain slightly below the input voltage by the forward voltage of the rectifier, preventing the output voltage from dropping to ground when the regulator is shutdown. Figure 37 provides a circuit modification to disconnect the output voltage from the input voltage at shutdown. Regardless of the state of the EN pin, when a voltage is applied to VIN of the ADP1612/ADP1613, a large current spike occurs due to the nonisolated path through the inductor and diode between VIN and VOUT. The high current is a result of the output capacitor charging. The peak value is dependent on the inductor, output capacitor, and any load active on the output of the regulator. Rev. A | Page 12 of 28 ADP1612/ADP1613 APPLICATIONS INFORMATION SETTING THE OUTPUT VOLTAGE The ADP1612/ADP1613 feature an adjustable output voltage range of VIN to 20 V. The output voltage is set by the resistor voltage divider, R1 and R2, (see Figure 34) from the output voltage (VOUT) to the 1.235 V feedback input at FB. Use the following equation to determine the output voltage: VOUT = 1.235 × (1 + R1/R2) (1) For CCM duty cycles greater than 50% that occur with input voltages less than one-half the output voltage, slope compensation is required to maintain stability of the current-mode regulator. For stable current-mode operation, ensure that the selected inductance is equal to or greater than the minimum calculated inductance, LMIN, for the application parameters in the following equation: L > L MIN = Choose R1 based on the following equation: − 1.235 ⎞ ⎛V R1 = R2 × ⎜ OUT ⎟ 1.235 ⎝ ⎠ (2) INDUCTOR SELECTION The inductor is an essential part of the step-up switching converter. It stores energy during the on time of the power switch, and transfers that energy to the output through the output rectifier during the off time. To balance the tradeoffs between small inductor current ripple and efficiency, inductance values in the range of 4.7 μH to 22 μH are recommended. In general, lower inductance values have higher saturation current and lower series resistance for a given physical size. However, lower inductance results in a higher peak current that can lead to reduced efficiency and greater input and/or output ripple and noise. A peak-to-peak inductor ripple current close to 30% of the maximum dc input current typically yields an optimal compromise. For determining the inductor ripple current in continuous operation, the input (VIN) and output (VOUT) voltages determine the switch duty cycle (D) by the following equation: D= VOUT − VIN (3) VOUT D (4) f SW The inductor ripple current (ΔIL) in steady state is calculated by ΔI L = VIN × t ON L (5) Solve for the inductance value (L) by the following equation: L= VIN × t ON ΔI L (7) 2.7 × f SW Inductors smaller than the 4.7 μH to 22 μH recommended range can be used as long as Equation 7 is satisfied for the given application. For input/output combinations that approach the 90% maximum duty cycle, doubling the inductor is recommended to ensure stable operation. Table 5 suggests a series of inductors for use with the ADP1612/ADP1613. Table 5. Suggested Inductors Manufacturer Sumida Coilcraft Toko Würth Elektronik Part Series CMD4D11 CDRH4D28CNP CDRH5D18NP CDRH6D26HPNP DO3308P DO3316P D52LC D62LCB D63LCB WE-TPC WE-PD, PD2, PD3, PD4 Dimensions L × W × H (mm) 5.8 × 4.4 × 1.2 5.1 × 5.1 × 3.0 6.0 × 6.0 × 2.0 7.0 × 7.0 × 2.8 12.95 × 9.4 × 3.0 12.95 × 9.4 × 5.21 5.2 × 5.2 × 2.0 6.2 × 6.3 × 2.0 6.2 × 6.3 × 3.5 Assorted Assorted CHOOSING THE INPUT AND OUTPUT CAPACITORS Using the duty cycle and switching frequency, fSW, determine the on time by the following equation: t ON = (VOUT − 2 × VIN ) (6) The ADP1612/ADP1613 require input and output bypass capacitors to supply transient currents while maintaining constant input and output voltages. Use a low equivalent series resistance (ESR), 10 μF or greater input capacitor to prevent noise at the ADP1612/ADP1613 input. Place the capacitor between VIN and GND as close to the ADP1612/ADP1613 as possible. Ceramic capacitors are preferred because of their low ESR characteristics. Alternatively, use a high value, medium ESR capacitor in parallel with a 0.1 μF low ESR capacitor as close to the ADP1612/ADP1613 as possible. Ensure that the peak inductor current (the maximum input current plus half the inductor ripple current) is below the rated saturation current of the inductor. Likewise, make sure that the maximum rated rms current of the inductor is greater than the maximum dc input current to the regulator. Rev. A | Page 13 of 28 ADP1612/ADP1613 The output capacitor maintains the output voltage and supplies current to the load while the ADP1612/ADP1613 switch is on. The value and characteristics of the output capacitor greatly affect the output voltage ripple and stability of the regulator. A low ESR ceramic dielectric capacitor is preferred. The output voltage ripple (ΔVOUT) is calculated as follows: ΔVOUT = I ×t QC = L ON COUT COUT (8) where: QC is the charge removed from the capacitor. tON is the on time of the switch. COUT is the output capacitance. IL is the average inductor current. t ON = D f SW I L × (VOUT − VIN ) f SW × VOUT × ΔVOUT (10) The regulator loop gain is AVL = (11) The output rectifier conducts the inductor current to the output capacitor and load while the switch is off. For high efficiency, minimize the forward voltage drop of the diode. For this reason, Schottky rectifiers are recommended. However, for high voltage, high temperature applications, where the Schottky rectifier reverse leakage current becomes significant and can degrade efficiency, use an ultrafast junction diode. Ensure that the diode is rated to handle the average output load current. Many diode manufacturers derate the current capability of the diode as a function of the duty cycle. Verify that the output diode is rated to handle the average output load current with the minimum duty cycle. The minimum duty cycle of the ADP1612/ADP1613 is VOUT V VFB × IN × G MEA × Z COMP × GCS × Z OUT VOUT VOUT (14) where: AVL is the loop gain. VFB is the feedback regulation voltage, 1.235 V. VOUT is the regulated output voltage. VIN is the input voltage. GMEA is the error amplifier transconductance gain. ZCOMP is the impedance of the series RC network from COMP to GND. GCS is the current sense transconductance gain (the inductor current divided by the voltage at COMP), which is internally set by the ADP1612/ADP1613. ZOUT is the impedance of the load and output capacitor. (12) where VIN(MAX) is the maximum input voltage. The following are suggested Schottky diode manufacturers: • • (13) To stabilize the regulator, ensure that the regulator crossover frequency is less than or equal to one-fifth of the right-half plane zero. DIODE SELECTION VOUT − VIN ( MAX ) 2 ⎞ R LOAD ⎟ × ⎟ 2π × L ⎠ (9) Multilayer ceramic capacitors are recommended for this application. D MIN = The step-up converter produces an undesirable right-half plane zero in the regulation feedback loop. This requires compensating the regulator such that the crossover frequency occurs well below the frequency of the right-half plane zero. The righthalf plane zero is determined by the following equation: where: FZ(RHP) is the right-half plane zero. RLOAD is the equivalent load resistance or the output voltage divided by the load current. Choose the output capacitor based on the following equation: C OUT ≥ The ADP1612/ADP1613 use external components to compensate the regulator loop, allowing optimization of the loop dynamics for a given application. ⎛ V FZ (RHP ) = ⎜⎜ IN ⎝ VOUT and − VIN V D = OUT VOUT LOOP COMPENSATION ON Semiconductor Diodes, Inc. Rev. A | Page 14 of 28 ADP1612/ADP1613 To determine the crossover frequency, it is important to note that, at that frequency, the compensation impedance (ZCOMP) is dominated by a resistor, and the output impedance (ZOUT) is dominated by the impedance of an output capacitor. Therefore, when solving for the crossover frequency, the equation (by definition of the crossover frequency) is simplified to V VFB × IN × G MEA × RCOMP × GCS × VOUT VOUT 1 =1 2π × f C × C OUT AVL = (15) where: fC is the crossover frequency. RCOMP is the compensation resistor. 2π × f C × C OUT × (VOUT )2 (16) VFB × VIN × G MEA × GCS where: VFB = 1.235 V. GMEA = 80 μA/V. GCS = 13.4 A/V. RCOMP 2 π × f C × RCOMP (18) where CCOMP is the compensation capacitor. ERROR AMPLIFIER COMP gm VBG ESR × C OUT RCOMP (19) For low ESR output capacitance such as with a ceramic capacitor, C2 is optional. For optimal transient performance, RCOMP and CCOMP might need to be adjusted by observing the load transient response of the ADP1612/ADP1613. For most applications, the compensation resistor should be within the range of 4.7 kΩ to 100 kΩ and the compensation capacitor should be within the range of 100 pF to 3.3 nF. 1 RCOMP 06772-004 C2 CCOMP Upon startup (EN ≥ 1.6 V), the voltage at SS ramps up slowly by charging the soft start capacitor (CSS) with an internal 5 μA current source (ISS). As the soft start capacitor charges, it limits the peak current allowed by the part to prevent excessive overshoot at startup. The necessary soft start capacitor, CSS, for a specific overshoot and start-up time can be calculated for the maximum load condition when the part is at current limit by: (17) Once the compensation resistor is known, set the zero formed by the compensation capacitor and resistor to one-fourth of the crossover frequency, or FB 2 C2 = C SS = I SS 4746 × f C × C OUT × (VOUT ) 2 = VIN C COMP = Solve for C2 as follows: SOFT START CAPACITOR Solve for RCOMP, RCOMP = The capacitor, C2, is chosen to cancel the zero introduced by output capacitance, ESR. Δt VSS (20) where: ISS = 5 μA (typical). VSS = 1.2 V. Δt = startup time, at current limit. If the applied load does not place the part at current limit, the necessary CSS will be smaller. A 33 nF soft start capacitor results in negligible input current overshoot at start up, and therefore is suitable for most applications. However, if an unusually large output capacitor is used, a longer soft start period is required to prevent input inrush current. Conversely, if fast startup is a requirement, the soft start capacitor can be reduced or removed, allowing the ADP1612/ADP1613 to start quickly, but allowing greater peak switch current. Figure 35. Compensation Components Rev. A | Page 15 of 28 ADP1612/ADP1613 TYPICAL APPLICATION CIRCUITS The ADP1612 is geared toward applications requiring input voltages as low as 1.8 V, where the ADP1613 is more suited for applications needing the output power capabilities of a 2.0 A switch. The primary differences are shown in Table 6. STEP-UP REGULATOR CIRCUIT EXAMPLES ADP1612 Step-Up Regulator L1 4.7µH D1 3A, 40V VOUT = 5V VIN = 1.8V TO 4.2V 6 Table 6. ADP1612/ADP1613 Differences ADP1612 1.4 A 1.8 V to 5.5 V ADP1613 2.0 A 2.5 V to 5.5 V 3 EN 7 FREQ 8 SS FB 2 COMP 1 CSS 33nF The Step-Up Regulator Circuit Examples section recommends component values for several common input, output, and load conditions. The equations in the Applications Information section can be used to select components for alternate configurations. EN 7 FREQ VOUT SW 5 R1 FB 2 1.3MHz 650kHz (DEFAULT) 8 R2 COMP 1 SS GND CSS COUT RCOMP 4 70 60 50 CCOMP VIN = 1.8V VIN = 2.7V VIN = 3.3V VIN = 4.2V 40 06772-005 CIN 30 1 10 Figure 36. Step-Up Regulator The modified step-up circuit in Figure 37 incorporates true shutdown capability advantageous for battery-powered applications requiring low standby current. Driving the EN pin below 0.3 V shuts down the ADP1612/ADP1613 and completely disconnects the input from the output. L1 VIN Q1 ADP1612/ ADP1613 A 6 VIN R3 10kΩ 8 SS ON OFF CSS 1k 10k Figure 39. ADP1612 Efficiency vs. Load Current VOUT = 5 V, fSW = 650 kHz T VOUT = 5V fSW = 650kHz OUTPUT VOLTAGE (50mV/DIV) AC-COUPLED VOUT LOAD CURRENT (50mA/DIV) FB 2 1.3MHz 7 FREQ 650kHz (DEFAULT) Q1 B 100 LOAD CURRENT (mA) R1 3 EN CIN D1 SW 5 R2 COMP 1 GND 4 RCOMP CCOMP COUT 06772-006 NTGD1100L ADP1612 Figure 37. Step-Up Regulator with True Shutdown Rev. A | Page 16 of 28 TIME (100µs/DIV) Figure 40. ADP1612 50 mA to 150 mA Load Transient (VIN = 3.3 V) VOUT = 5 V, fSW = 650 kHz 06772-041 3 CCOMP: ECJ-2VB1H332K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K 80 D1 ON OFF RCOMP 6.8kΩ CCOMP 3300pF VOUT = 5V fSW = 650kHz TA = 25°C 90 EFFICIENCY (%) VIN COUT 10µF 100 L1 6 4 R2 10kΩ Figure 38. ADP1612 Step-Up Regulator Configuration VOUT = 5 V, fSW = 650 kHz The circuit in Figure 36 shows the ADP1612/ADP1613 in a basic step-up configuration. ADP1612/ ADP1613 GND L1: DO3316P-472ML D1: MBRA340T3G R1: RC0805FR-0730KL R2: CRCW080510K0FKEA RCOMP: RC0805JR-076K8L STEP-UP REGULATOR VIN R1 30kΩ 06772-042 Parameter Current Limit Input Voltage Range OFF CIN 10µF SW 5 VIN ADP1612 ON 06772-040 Both the ADP1612 and ADP1613 can be used in the application circuits in this section. ADP1612/ADP1613 L1 4.7µH L1 10µH OFF CIN 10µF SW 5 VIN ADP1612 3 EN 7 FREQ 8 SS 6 R1 30kΩ FB 2 COMP 1 CSS 33nF GND 4 L1: DO3316P-472ML D1: MBRA340T3G R1: RC0805FR-0730KL R2: CRCW080510K0FKEA RCOMP: RC0805JR-0712KL R2 10kΩ OFF CIN 10µF COUT 10µF SW 5 VIN ADP1612 ON 3 EN 7 FREQ 8 SS COMP 1 CSS 33nF CCOMP: ECJ-2VB1H122K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K R1 86.6kΩ FB 2 RCOMP 12kΩ CCOMP 1200pF GND 4 L1: DO3316P-103ML D1: DFLS220L-7 R1: ERJ-6ENF8662V R2: CRCW080510K0FKEA RCOMP: RC0805JR-0722KL 06772-043 6 ON D1 2A, 20V VOUT = 12V VIN = 2.7V TO 5V Figure 41. ADP1612 Step-Up Regulator Configuration VOUT = 5 V, fSW = 1.3 MHz COUT 10µF R2 10kΩ RCOMP 22kΩ CCOMP 1800pF CCOMP: ECJ-2VB1H182K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K 06772-046 D1 3A, 40V V OUT = 5V VIN = 1.8V TO 4.2V Figure 44. ADP1612 Step-Up Regulator Configuration VOUT = 12 V, fSW = 650 kHz 100 100 ADP1612 VOUT = 5V fSW = 1.3MHz TA = 25°C 90 ADP1612 VOUT = 12V fSW = 650kHz TA = 25°C 90 EFFICIENCY (%) EFFICIENCY (%) 80 70 60 80 70 60 50 100 LOAD CURRENT (mA) 1k 10k 40 1 Figure 42. ADP1612 Efficiency vs. Load Current VOUT = 5 V, fSW = 1.3 MHz T 1k Figure 45. ADP1612 Efficiency vs. Load Current VOUT = 12 V, fSW = 650 kHz T VOUT = 5V fSW = 1.3MHz OUTPUT VOLTAGE (50mV/DIV) AC-COUPLED VOUT = 12V fSW = 650kHz OUTPUT VOLTAGE (100mV/DIV) AC-COUPLED LOAD CURRENT (50mA/DIV) 06772-045 LOAD CURRENT (50mA/DIV) TIME (100µs/DIV) 10 100 LOAD CURRENT (mA) TIME (100µs/DIV) Figure 43. ADP1612 50 mA to 150 mA Load Transient (VIN = 3.3 V) VOUT = 5 V, fSW = 1.3 MHz 06772-048 10 06772-044 30 1 VIN = 2.7V VIN = 3.3V VIN = 4.2V VIN = 5.0V 50 06772-047 VIN = 1.8V VIN = 2.7V VIN = 3.3V VIN = 4.2V 40 Figure 46. ADP1612 50 mA to 150 mA Load Transient (VIN = 3.3 V) VOUT = 12 V, fSW = 650 kHz Rev. A | Page 17 of 28 ADP1612/ADP1613 L1 6.8µH L1 15µH OFF CIN 10µF SW 5 VIN ADP1612 3 EN 7 FREQ 8 SS 6 FB 2 COMP 1 CSS 33nF GND 4 L1: DO3316P-682ML D1: DFLS220L-7 R1: ERJ-6ENF8662V R2: CRCW080510K0FKEA RCOMP: RC0805JR-0718KL COUT 10µF R2 10kΩ OFF CIN 10µF SW 5 VIN ADP1612 ON R1 86.6kΩ 3 EN 7 FREQ 8 SS COMP 1 CSS 33nF CCOMP: CC0805KRX7R9BB681 CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K R1 110kΩ FB 2 RCOMP 18kΩ CCOMP 680pF GND 4 L1: DO3316P-153ML D1: DFLS220L-7 R1: ERJ-6ENF1103V R2: CRCW080510K0FKEA RCOMP: RC0805JR-0722KL 06772-049 6 ON D1 2A, 20V VOUT = 15V VIN = 2.7V TO 5V Figure 47. ADP1612 Step-Up Regulator Configuration VOUT = 12 V, fSW = 1.3 MHz COUT 10µF R2 10kΩ RCOMP 22kΩ CCOMP 1800pF CCOMP: ECJ-2VB1H182K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K 06772-052 D1 2A, 20V VOUT = 12V VIN = 2.7V TO 5V Figure 50. ADP1612 Step-Up Regulator Configuration VOUT = 15 V, fSW = 650 kHz 100 100 ADP1612 VOUT = 12V fSW = 1.3MHz TA = 25°C 90 ADP1612 VOUT = 15V fSW = 650kHz TA = 25°C 90 EFFICIENCY (%) EFFICIENCY (%) 80 70 60 80 70 60 50 1k 40 1 Figure 48. ADP1612 Efficiency vs. Load Current VOUT = 12 V, fSW = 1.3 MHz T 1k Figure 51. ADP1612 Efficiency vs. Load Current VOUT = 15 V, fSW = 650 kHz VOUT = 12V fSW = 1.3MHz T OUTPUT VOLTAGE (100mV/DIV) AC-COUPLED VOUT = 15V fSW = 650kHz OUTPUT VOLTAGE (200mV/DIV) AC-COUPLED LOAD CURRENT (50mA/DIV) 06772-051 LOAD CURRENT (50mA/DIV) TIME (100µs/DIV) 10 100 LOAD CURRENT (mA) TIME (100µs/DIV) Figure 49. ADP1612 50 mA to 150 mA Load Transient (VIN = 3.3 V) VOUT = 12 V, fSW = 1.3 MHz 06772-054 10 100 LOAD CURRENT (mA) 06772-050 30 1 VIN = 2.7V VIN = 3.3V VIN = 4.2V VIN = 5.0V 50 06772-053 VIN = 2.7V VIN = 3.3V VIN = 4.2V VIN = 5.0V 40 Figure 52. ADP1612 50 mA to 150 mA Load Transient (VIN = 3.3 V) VOUT = 15 V, fSW = 650 kHz Rev. A | Page 18 of 28 ADP1612/ADP1613 ADP1613 Step-Up Regulator L1 10µH L1 10µH OFF CIN 10µF SW 5 VIN ADP1612 3 EN 7 FREQ 8 SS 6 R1 110kΩ FB 2 COMP 1 CSS 33nF GND 4 L1: DO3316P-103ML D1: DFLS220L-7 R1: ERJ-6ENF1103V R2: CRCW080510K0FKEA RCOMP: RC0805JR-0710KL COUT 10µF R2 10kΩ OFF CIN 10µF 3 EN 7 FREQ 8 SS COMP 1 RCOMP 10kΩ CCOMP 1800pF CSS 33nF CCOMP: ECJ-2VB1H182K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K R1 86.6kΩ FB 2 GND 4 L1: DO3316P-103ML D1: MBRA340T3G R1: ERJ-6ENF8662V R2: CRCW080510K0FKEA RCOMP: RC0805JR-0712KL Figure 53. ADP1612 Step-Up Regulator Configuration VOUT =15 V, fSW = 1.3 MHz COUT 10µF R2 10kΩ RCOMP 12kΩ CCOMP 2200pF CCOMP: ECJ-2VB1H222K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K Figure 56. ADP1613 Step-Up Regulator Configuration VOUT = 12 V, fSW = 650 kHz 100 100 ADP1613 VOUT = 12V fSW = 650kHz TA = 25°C ADP1612 VOUT = 15V fSW = 1.3MHz TA = 25°C 90 90 80 EFFICIENCY (%) 80 70 60 70 60 50 VIN = 2.7V VIN = 3.3V VIN = 4.2V VIN = 5.0V 30 1 10 100 LOAD CURRENT (mA) 1k 30 1 T VOUT = 15V fSW = 1.3MHz 1k VOUT = 12V fSW = 650kHz OUTPUT VOLTAGE (200mV/DIV) AC-COUPLED OUTPUT VOLTAGE (200mV/DIV) AC-COUPLED LOAD CURRENT (50mA/DIV) LOAD CURRENT (50mA/DIV) 06772-057 TIME (100µs/DIV) 10 100 LOAD CURRENT (mA) Figure 57. ADP1613 Efficiency vs. Load Current VOUT = 12 V, fSW = 650 kHz Figure 54. ADP1612 Efficiency vs. Load Current VOUT =15 V, fSW = 1.3 MHz T VIN = 2.7V VIN = 3.3V VIN = 4.2V VIN = 5.0V 40 06772-056 40 TIME (100µs/DIV) Figure 55. ADP1612 50 mA to 150 mA Load Transient (VIN = 3.3 V) VOUT =15 V, fSW = 1.3 MHz Figure 58. ADP1613 50 mA to 150 mA Load Transient (VIN = 5 V) VOUT = 12 V, fSW = 650 kHz Rev. A | Page 19 of 28 06772-059 50 06772-060 EFFICIENCY (%) SW 5 VIN ADP1613 ON 06772-055 6 ON D1 3A, 40V VOUT = 12V VIN = 2.7V TO 5V 06772-058 D1 2A, 20V VOUT = 15V VIN = 2.7V TO 5V ADP1612/ADP1613 L1 6.8µH L1 15µH OFF CIN 10µF SW 5 VIN ADP1613 3 EN 7 FREQ 8 SS 6 FB 2 COMP 1 CSS 33nF GND 4 L1: DO3316P-682ML D1: MBRA340T3G R1: ERJ-6ENF8662V R2: CRCW080510K0FKEA RCOMP: RC0805JR-0710KL COUT 10µF R2 10kΩ 3 EN 7 FREQ 8 SS COMP 1 CSS 33nF CCOMP: ECJ-2VB1H102K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K R1 110kΩ FB 2 RCOMP 10kΩ CCOMP 1000pF GND 4 L1: DO3316P-153ML D1: MBRA340T3G R1: ERJ-6ENF1103V R2: CRCW080510K0FKEA RCOMP: RC0805JR-0710KL Figure 59. ADP1613 Step-Up Regulator Configuration VOUT = 12 V, fSW = 1.3 MHz R2 10kΩ COUT 10µF RCOMP 10kΩ CCOMP 1800pF CCOMP: ECJ-2VB1H182K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K Figure 62. ADP1613 Step-Up Regulator Configuration VOUT = 15 V, fSW = 650 kHz 100 100 ADP1613 VOUT = 12V fSW = 1.3MHz TA = 25°C 90 ADP1613 VOUT = 15V fSW = 650kHz TA = 25°C 90 80 EFFICIENCY (%) 80 70 60 70 60 50 VIN = 2.7V VIN = 3.3V VIN = 4.2V VIN = 5.0V 30 10 100 LOAD CURRENT (mA) 1k 30 1 Figure 60. ADP1613 Efficiency vs. Load Current VOUT = 12 V, fSW = 1.3 MHz T 1k Figure 63. ADP1613 Efficiency vs. Load Current VOUT = 15 V, fSW = 650 kHz T VOUT = 12V fSW = 1.3MHz OUTPUT VOLTAGE (100mV/DIV) AC-COUPLED VOUT = 15V fSW = 650kHz OUTPUT VOLTAGE (200mV/DIV) AC-COUPLED LOAD CURRENT (50mA/DIV) TIME (100µs/DIV) 10 100 LOAD CURRENT (mA) LOAD CURRENT (50mA/DIV) TIME (100µs/DIV) Figure 61. ADP1613 50 mA to 150 mA Load Transient (VIN = 5 V) VOUT = 12 V, fSW = 1.3 MHz 06772-066 1 VIN = 3.3V VIN = 4.2V VIN = 5.0V VIN = 5.5V 40 06772-062 40 Figure 64. ADP1613 50 mA to 150 mA Load Transient (VIN = 5 V) VOUT = 15 V, fSW = 650 kHz Rev. A | Page 20 of 28 06772-065 50 06772-063 EFFICIENCY (%) OFF CIN 10µF SW 5 VIN ADP1613 ON R1 86.6kΩ 06772-061 6 ON D1 3A, 40V VOUT = 15V VIN = 3.3V TO 5.5V 06772-064 D1 3A, 40V VOUT = 12V VIN = 2.7V TO 5V ADP1612/ADP1613 L1 10µH L1 15µH OFF CIN 10µF SW 5 VIN ADP1613 3 EN 7 FREQ 8 SS 6 FB 2 COMP 1 CSS 33nF GND 4 L1: DO3316P-103ML D1: MBRA340T3G R1: ERJ-6ENF1103V R2: CRCW080510K0FKEA RCOMP: RC0805JR-078K2L R2 10kΩ COUT 10µF 3 EN 7 FREQ 8 SS COMP 1 CSS 33nF CCOMP: ECJ-2VB1H122K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K R1 150kΩ FB 2 RCOMP 8.2kΩ CCOMP 1200pF GND 4 L1: DO3316P-153ML D1: MBRA340T3G R1: RC0805JR-07150KL R2: CRCW080510K0FKEA RCOMP: RC0805JR-0718KL Figure 65. ADP1613 Step-Up Regulator Configuration VOUT = 15 V, fSW = 1.3 MHz R2 10kΩ COUT 10µF RCOMP 18kΩ CCOMP 820pF CCOMP: CC0805KRX7R9BB821 CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K Figure 68. ADP1613 Step-Up Regulator Configuration VOUT = 20 V, fSW = 650 kHz 100 100 ADP1613 VOUT = 15V fSW = 1.3MHz TA = 25°C 90 ADP1613 VOUT = 20V fSW = 650kHz TA = 25°C 90 80 EFFICIENCY (%) 80 70 60 50 70 60 50 20 1 10 100 LOAD CURRENT (mA) 1k 30 06772-068 30 1 Figure 66. ADP1613 Efficiency vs. Load Current VOUT = 15 V, fSW = 1.3 MHz T 10 100 LOAD CURRENT (mA) 1k Figure 69. ADP1613 Efficiency vs. Load Current VOUT = 20 V, fSW = 650 kHz T VOUT = 15V fSW = 1.3MHz OUTPUT VOLTAGE (200mV/DIV) AC-COUPLED VOUT = 20V fSW = 650kHz OUTPUT VOLTAGE (200mV/DIV) AC-COUPLED LOAD CURRENT (50mA/DIV) LOAD CURRENT (50mA/DIV) TIME (100µs/DIV) VIN = 3.3V VIN = 4.2V VIN = 5.0V VIN = 5.5V 40 TIME (100µs/DIV) Figure 67. ADP1613 50 mA to 150 mA Load Transient (VIN = 5 V) VOUT = 15 V, fSW = 1.3 MHz Figure 70. ADP1613 50 mA to 150 mA Load Transient (VIN = 5 V) VOUT = 20 V, fSW = 650 kHz Rev. A | Page 21 of 28 06772-071 VIN = 3.3V VIN = 4.2V VIN = 5.0V VIN = 5.5V 06772-072 40 06772-069 EFFICIENCY (%) OFF CIN 10µF SW 5 VIN ADP1613 ON R1 110kΩ 06772-067 6 ON D1 3A, 40V VOUT = 20V VIN = 3.3V TO 5.5V 06772-070 D1 3A, 40V VOUT = 15V VIN = 3.3V TO 5.5V ADP1612/ADP1613 SEPIC CONVERTER L1 10µH ADP1613 3 EN 7 FREQ 8 SS R1 150kΩ FB 2 COMP 1 CSS 33nF GND 4 L1: DO3316P-103ML D1: MBRA340T3G R1: RC0805JR-07150KL R2: CRCW080510K0FKEA RCOMP: RC0805JR-078K2L R2 10kΩ COUT 10µF RCOMP 8.2kΩ CCOMP 1200pF CCOMP: ECL-2VB1H122K CIN: GRM21BR61C106KE15L COUT: GRM32DR71E106KA12L CSS: ECJ-2VB1H333K Figure 71. ADP1613 Step-Up Regulator Configuration VOUT = 20 V, fSW = 1.3 MHz The input and the output are dc isolated by a coupling capacitor (C1). In steady state, the average voltage of C1 is the input voltage. When the ADP1612/ADP1613 switch turns on and the diode turns off, the input voltage provides energy to L1 and C1 provides energy to L2. When the ADP1612/ADP1613 switch turns off and the diode turns on, the energy in L1 and L2 is released to charge the output capacitor (COUT) and the coupling capacitor (C1) and to supply current to the load. L1 DO3316P 4.7µH 100 ADP1613 VOUT = 20V fSW = 1.3MHz TA = 25°C 90 6 VIN 3 EN 7 FREQ 8 SS C1 10µF CIN 10µF OFF 60 50 CSS 40 VIN = 3.3V VIN = 4.2V VIN = 5.0V VIN = 5.5V 1 10 100 LOAD CURRENT (mA) 1k L2 DO3316P 4.7µH R1 16.9kΩ FB 2 COMP 1 GND 4 RCOMP 82kΩ R2 10kΩ COUT 10µF CCOMP 220pF TFT LCD BIAS SUPPLY Figure 75 shows a power supply circuit for TFT LCD module applications. This circuit has +10 V, −5 V, and +22 V outputs. The +10 V is generated in the step-up configuration. The −5 V and +22 V are generated by the charge-pump circuit. During the step-up operation, the SW node switches between +10 V and ground (neglecting the forward drop of the diode and on resistance of the switch). When the SW node is high, C5 charges up to +10 V. When the SW node is low, C5 holds its charge and forward-biases D8 to charge C6 to −10 V. The Zener diode (D9) clamps and regulates the output to −5 V. Figure 72. ADP1613 Efficiency vs. Load Current VOUT = 20 V, fSW = 1.3 MHz T VOUT = 3.3V Figure 74. SEPIC Converter 20 06772-074 30 MBRA210LT 2A, 10V SW 5 ON 70 VOUT = 20V fSW = 1.3MHz OUTPUT VOLTAGE (200mV/DIV) AC-COUPLED LOAD CURRENT (50mA/DIV) The VGH output is generated in a similar manner by the chargepump capacitors, C1, C2, and C4. The output voltage is tripled and regulated down to 22 V by the Zener diode, D5. TIME (100µs/DIV) 06772-075 EFFICIENCY (%) ADP1612/ ADP1613 VIN = 2.0V TO 5.5V 80 Figure 73. ADP1613 50 mA to 150 mA Load Transient (VIN = 5 V) VOUT = 20 V, fSW = 1.3 MHz Rev. A | Page 22 of 28 06772-008 OFF SW 5 VIN 06772-073 6 ON CIN 10µF The circuit in Figure 74 shows the ADP1612/ADP1613 in a single-ended primary inductance converter (SEPIC) topology. This topology is useful for an unregulated input voltage, such as a battery-powered application in which the input voltage can vary between 2.7 V to 5 V and the regulated output voltage falls within the input voltage range. D1 3A, 40V VOUT = 20V VIN = 3.3V TO 5.5V ADP1612/ADP1613 BAV99 R4 200Ω VGL –5V D8 C6 10µF D9 BZT52C5VIS R3 200Ω D5 C4 10nF BAV99 C3 10µF C5 10nF D5 BZT52C22 VGH +22V D4 D7 C1 10nF BAV99 D3 C2 1µF DO3316P 4.7µH D2 ADP1612/ ADP1613 VIN = 3.3V 6 VIN 3 EN 7 FREQ 8 SS D1 ON OFF R1 71.5kΩ FB 2 1.3MHz 650kHz (DEFAULT) CSS R2 10kΩ COMP 1 GND 4 RCOMP 27kΩ CCOMP 1200pF Figure 75. TFT LCD Bias Supply Rev. A | Page 23 of 28 COUT 10µF 06772-007 CIN 10µF VOUT = 10V SW 5 ADP1612/ADP1613 PCB LAYOUT GUIDELINES For high efficiency, good regulation, and stability, a welldesigned printed circuit board layout is required. Use the following guidelines when designing printed circuit boards (also see Figure 34 for a block diagram and Figure 3 for a pin configuration). • • • 06772-076 • • Figure 76. Example Layout for ADP1612/ADP1613 Boost Application (Top Layer) • • 06772-077 • Figure 77. Example Layout for ADP1612/ADP1613 Boost Application (Bottom Layer) Rev. A | Page 24 of 28 Keep the low ESR input capacitor, CIN (labeled as C7 in Figure 76), close to VIN and GND. This minimizes noise injected into the part from board parasitic inductance. Keep the high current path from CIN (labeled as C7 in Figure 76) through the L1 inductor to SW and GND as short as possible. Keep the high current path from VIN through L1, the rectifier (D1) and the output capacitor, COUT (labeled as C4 in Figure 76) as short as possible. Keep high current traces as short and as wide as possible. Place the feedback resistors as close to FB as possible to prevent noise pickup. Connect the ground of the feedback network directly to an AGND plane that makes a Kelvin connection to the GND pin. Place the compensation components as close as possible to COMP. Connect the ground of the compensation network directly to an AGND plane that makes a Kelvin connection to the GND pin. Connect the softstart capacitor, CSS (labeled as C1 in Figure 76) as close to the device as possible. Connect the ground of the softstart capacitor to an AGND plane that makes a Kelvin connection to the GND pin. Avoid routing high impedance traces from the compensation and feedback resistors near any node connected to SW or near the inductor to prevent radiated noise injection. ADP1612/ADP1613 OUTLINE DIMENSIONS 3.20 3.00 2.80 8 3.20 3.00 2.80 1 5.15 4.90 4.65 5 4 PIN 1 IDENTIFIER 0.65 BSC 0.95 0.85 0.75 15° MAX 1.10 MAX 0.40 0.25 6° 0° 0.23 0.13 COMPLIANT TO JEDEC STANDARDS MO-187-AA 0.70 0.55 0.40 091709-A 0.15 0.05 COPLANARITY 0.10 Figure 78. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters ORDERING GUIDE Model ADP1612ARMZ-R7 1 ADP1613ARMZ-R71 ADP1612-5-EVALZ1 ADP1612-BL1-EVZ1 ADP1613-12-EVALZ1 ADP1613-BL1-EVZ1 1 Temperature Range −40°C to +125°C −40°C to +125°C Package Description 8-Lead Mini Small Outline Package [MSOP] 8-Lead Mini Small Outline Package [MSOP] Evaluation Board, 5 V Output Voltage Configuration Blank Evaluation Board Evaluation Board, 12 V Output Voltage Configuration Blank Evaluation Board Z = RoHS Compliant Part. Rev. A | Page 25 of 28 Package Option RM-8 RM-8 Branding L7Z L96 ADP1612/ADP1613 NOTES Rev. A | Page 26 of 28 ADP1612/ADP1613 NOTES Rev. A | Page 27 of 28 ADP1612/ADP1613 NOTES ©2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D06772-0-9/09(A) Rev. A | Page 28 of 28