Micropower Step-Up/Step-Down Fixed 3.3 V, 5 V, 12 V, Adjustable High Frequency Switching Regulator ADP3000 FEATURES FUNCTIONAL BLOCK DIAGRAMS ILIM 1.245V REFERENCE SW1 400kHz OSCILLATOR DRIVER COMPARATOR R1 R2 GND SW2 ADP3000 SENSE Figure 1. VIN 2V TO 3.2V 100µF 10V O 3.3V 180mA 120V 1 2 ILIM VIN SW1 3 FB 8 (SENSE) GND SW2 5 4 + C1 100µF 10V C1, C2 = AVX TPS D107 M010R0100 L1 = SUMIDA CR43-6R8 00122-002 B SO Operating in pulse frequency mode (PFM), the device consumes only 500 µA, making it ideal for applications requiring low quiescent current. It delivers an output current of 180 mA at 3.3 V from a 2 V input in step-up mode, and an output current of 100 mA at 3 V from a 5 V input in step-down mode. The auxiliary gain amplifier can be used as a low battery detector, linear regulator, undervoltage lockout, or error amplifier. IN5817 ADP3000-3.3V The ADP3000 is a versatile step-up/step-down switching regulator. It operates from an input supply voltage of 2 V to 12 V in step-up mode, and from 2 V to 30 V in step-down mode. The ADP3000 operates at 400 kHz switching frequency. This allows the use of small external components (inductors and capacitors), making it convenient for space-constrained designs. 6.8µH Figure 2. Typical Application VIN 5V TO 6V C1 100µF 10V RLIM 120Ω 1 ILIM 2 3 VIN SW1 FB 8 ADP3000 SW2 4 GND 5 D1 1N5818 L1 10µH CL + 100µF 10V R2 150kΩ 1% VOUT 3V 100mA R1 110kΩ 1% C1, C2 = AVX TPS D107 M010R0100 L1 = SUMIDA CR43-100 Figure 3. Step-Down Mode Operation 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: 781.326.8703 © 2004 Analog Devices, Inc. All rights reserved. 00122-003 GENERAL DESCRIPTION A0 GAIN BLOCK/ ERROR AMP LE Notebook, palmtop computers Cellular telephones Hard disk drives Portable instruments Pagers A1 VIN 00122-001 APPLICATIONS SET TE Operates at supply voltages from 2 V to 30 V Works in step-up or step-down mode Very few external components required High frequency operation up to 400 kHz Low battery detector on-chip User-adjustable current limit Fixed and adjustable output voltage 8-lead PDIP, 8-lead SOIC, and 14-lead TSSOP packages Small inductors and capacitors ADP3000 TABLE OF CONTENTS Specifications..................................................................................... 3 Programming the Gain Block................................................... 11 Absolute Maximum Ratings............................................................ 4 Power Transistor Protection Diode in Step-Down Configuration ............................................................................. 11 Pin Configurations and Function Descriptions ........................... 5 Typical Performance Characteristics ............................................. 6 Theory of Operation ........................................................................ 9 Applications Information .............................................................. 10 Thermal Considerations............................................................ 11 Typical Application Circuits ......................................................... 13 Outline Dimensions ....................................................................... 15 Ordering Guide .......................................................................... 16 Component Selection................................................................. 10 Programming the Switching Current Limit............................ 10 9/04—Data Sheet Changed from Rev. 0 to Rev. A LE REVISION HISTORY TE ESD Caution.................................................................................. 4 B SO Added RU-14 Package ................................................. Universal Changes to Table 4.....................................................................10 Changes to Table 5.....................................................................10 Updated Outline Dimensions ..................................................15 Changes to Ordering Guide .....................................................16 O 1/97—Revision 0: Initial Version Rev. A | Page 2 of 16 ADP3000 SPECIFICATIONS 0°C ≤ TA ≤ +70°C, VIN = 3 V, unless otherwise noted.1 Table 1. COMPARATOR HYSTERESIS OUTPUT HYSTERESIS OSCILLATOR FREQUENCY DUTY CYCLE SWITCH-ON TIME SWITCH SATURATION VOLTAGE Step-Up Mode VFB < VREF ILIM tied to VIN, VFB= 0 TA = +25°C VIN = 3.0 V, ISW = 650 mA VIN = 5.0 V, ISW = 1 A VIN = 12 V, ISW = 650 mA ADP3000 VFB = 0 V VSET = VREF ISINK = 300 µA, VSET = 1.00 V 5 V ≤ VIN ≤ 30 V 2 V ≤ VIN ≤ 5 V B SO Step-Down Mode FEEDBACK PIN BIAS CURRENT SET PIN BIAS CURRENT GAIN BLOCK OUTPUT LOW REFERENCE LINE REGULATION GAIN BLOCK GAIN GAIN BLOCK CURRENT SINK CURRENT LIMIT CURRENT LIMIT TEMPERATURE COEFFICIENT RL = 100 kΩ4 VSET ≤ 1 V 220 Ω from ILIM to VIN SWITCH-OFF LEAKAGE CURRENT Measured at SW1 pin VSW1= 12 V, TA = +25°C TA = +25°C ISW1 ≤ 10 µA, switch off O MAXIMUM EXCURSION BELOW GND Symbol VIN Min 2.0 IQ VOUT 1.20 3.135 4.75 11.40 ADP3000 Typ Max 12.6 30.0 500 1.245 1.30 3.3 3.465 5.00 5.25 12.00 12.60 8 12.5 32 50 32 50 75 120 400 450 80 2 2.55 TE SHUT-DOWN QUIESCENT CURRENT COMPARATOR TRIP POINT VOLTAGE OUTPUT SENSE VOLTAGE Conditions Step-up mode Step-down mode VFB > 1.43 V; VSENSE > 1.1 × VOUT ADP30002 ADP3000-3.33 ADP3000-53 ADP3000-123 ADP3000 ADP3000-3.3 ADP3000-5 ADP3000-12 fOSC D tON VSAT LE Parameter INPUT VOLTAGE 1 350 65 1.5 0.5 IFB ISET VOL AV ISINK ILIM 1000 0.75 0.8 1.1 160 200 0.15 0.02 0.2 V 1.1 1.5 330 400 0.4 0.15 0.6 6000 300 400 −0.3 Unit V V µA V V V V mV mV mV mV kHz % µs V V nA nA V %/V %/V V/V µA mA %/°C 1 10 µA −400 −350 mV All limits at temperature extremes are guaranteed via correlation using standard statistical methods. This specification guarantees that both the high and low trip points of the comparator fall within the 1.20 V to 1.30 V range. The output voltage waveform will exhibit a saw-tooth shape due to the comparator hysteresis. The output voltage on the fixed output versions will always be within the specified range. 4 100 kΩ resistor connected between a 5 V source and the AO pin. 2 3 Rev. A | Page 3 of 16 ADP3000 ABSOLUTE MAXIMUM RATINGS Table 2. Rating 15 V 36 V 50 V −0.5 V to VIN 5.5 V 1.5 A 500 mW 0°C to +70°C −65°C to +150°C 300°C 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. TE Parameter Input Supply Voltage, Step-Up Mode Input Supply Voltage, Step-Down Mode SW1 Pin Voltage SW2 Pin Voltage Feedback Pin Voltage (ADP3000) Switch Current Maximum Power Dissipation Operating Temperature Range Storage Temperature Range Lead Temperature (Soldering, 10 s) Thermal Impedance R-8 RU-14 N-8 170°C/W 150°C/W 120°C/W ESD CAUTION O B SO LE ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although this product features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality. Rev. A | Page 4 of 16 ADP3000 PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS ILIM 1 SW1 3 SW2 4 ADP3000 FB (SENSE)* 7 SET VIN 2 TOP VIEW 6 AO (Not to Scale) 5 GND *FIXED VERSIONS Figure 6. 8-Lead SOIC (R-8) NC 2 13 FB ILIM 3 12 SET VIN 4 11 AO SW1 5 10 NC NC 6 9 NC SW2 7 8 GND Figure 5. 14-lead TSSOP (RU-14) Table 3. Pin Function Descriptions FB/SENSE O SET A2 A0 1.245V REFERENCE A1 1.245V REFERENCE DRIVER SW2 ADP3000 GND A0 FB R1 GND SW1 OSCILLATOR COMPARATOR Figure 7. Functional Block Diagram for Adjustable Version ILIM GAIN BLOCK/ ERROR AMP SW1 OSCILLATOR COMPARATOR A1 VIN ILIM GAIN BLOCK/ ERROR AMP 00122-006 VIN SET DRIVER ADP3000 R2 SENSE Figure 8. Functional Block Diagram for Fixed Version Rev. A | Page 5 of 16 SW2 00122-007 GND AO SET Function For normal conditions, connect to VIN. When lower current is required, connect a resistor between ILIM and VIN. To limit the switch current to 400 mA, connect a 220 Ω resistor. Input Voltage. Collector of Power Transistor. For step-down configuration, connect to VIN. For step-up configuration, connect to an inductor/diode. Emitter of Power Transistor. For step-down configuration, connect to inductor/diode. For step-up configuration, connect to ground. Do not allow pin to go more than a diode drop below ground. Ground. Auxiliary Gain Block (GB) Output. Open collector can sink 300 µA. This pin can be left open if not used. Auxiliary Gain Amplifier Input. The amplifier’s positive input is connected to the SET pin, and its negative input is connected to the 1.245 V reference. This pin can be left open if not used. On the ADP3000 (adjustable) version, this pin is connected to the comparator input. On the ADP3000-3.3, the ADP3000-5, and the ADP3000-12, the pin goes directly to the internal resistor divider that sets the output voltage. B SO SW2 TE 14 NC NC = NO CONNECT VIN SW1 SET LE 1 Mnemonic ILIM FB (SENSE)* 7 *FIXED VERSIONS 00122-035 NC TOP VIEW (Not to Scale) 8 6 AO TOP VIEW SW2 4 (Not to Scale) 5 GND Figure 4. 8-Lead Plastic DIP (N-8) ADP3000 ADP3000 SW1 3 00122-004 VIN 2 8 00122-005 ILIM 1 ADP3000 TYPICAL PERFORMANCE CHARACTERISTICS 2.5 406 OSCILLATOR FREQUENCY @ TA = 25°C 405 OSCILLATOR FREQUENCY (kHz) 1.5 VIN = 5V @ TA = 25°C 1.0 VIN = 3V @ TA = 25°C 1.2 1.4 1.5 398 2 Figure 9. Switch-On Voltage vs. Switch Current in Step-Up Mode 0.8 10 12 15 18 INPUT VOLTAGE (V) 0.2 0.2 0.3 0.4 0.5 0.6 SWITCH CURRENT (A) 0.8 0.9 1200 30 TA = 0°C 600 400 TA = 85°C 0.4 0.3 0.2 10 100 1k RLIM (Ω) Figure 13. Maximum Switch Current vs. RLIM in Step-Down Mode (5 V) 1.8 VIN = 12V TA = 25°C 1.6 TA = 0°C 1.4 SWITCH CURRENT (A) O 800 TA = 25°C 0.5 1 QUIESCENT CURRENT @ TA = 25°C 1000 27 0 Figure 10. Saturation Voltage vs. Switch Current in Step-Down Mode 1400 24 0.1 00122-009 0.4 21 VIN = 5V LE 0.6 SWITCH CURRENT (A) VIN = 12V @ TA = 25°C 0.8 B SO VCE(SAT) (V) 8 0.6 1.0 1.2 TA = 85°C 1.0 0.8 0.6 0.4 200 0 1.5 0.2 3.0 6 9 12 15 18 21 INPUT VOLTAGE (V) 24 Figure 11. Quiescent Current vs. Input Voltage 27 30 0 00122-010 QUIESCENT CURRENT (µA) 6 0.7 VIN = 5V @ TA = 25°C 1.2 4 Figure 12. Oscillator Frequency vs. Input Voltage 1.4 0 0.1 400 00122-011 0.6 0.8 1.0 SWITCH CURRENT (A) 401 TE 0.4 00122-008 0.2 402 399 VIN = 2V @ TA = 25°C 0 0.1 403 00122-A-012 0.5 404 1 10 100 RLIM (Ω) 1k 00122-013 ON VOLTAGE (V) 2.0 Figure 14. Maximum Switch Current vs. RLIM in Step-Down Mode (12 V) Rev. A | Page 6 of 16 ADP3000 1.8 100 VIN = 3V 90 1.6 80 TA = 0°C 70 1.2 DUTY CYCLE (%) TA = 25°C 1.0 TA = 85°C 0.8 0.6 0.4 60 50 40 30 20 0.2 10 100 1k RLIM (Ω) Figure 15. Maximum Switch Current vs. RLIM in Step-Up Mode (3 V) 0 –40 0 25 TEMPERATURE (°C(T A)) 70 85 TE 1 00122-014 10 0 00122-017 SWITCH CURRENT (A) 1.4 Figure 18. Duty Cycle vs. Temperature 440 0.56 430 SATURATION VOLTAGE (V) LE 400 390 380 370 360 340 330 –40 0 25 TEMPERATURE (°C(T A)) 70 85 2.20 2.10 2.05 2.00 1.95 0 25 TEMPERATURE (°C(T A)) 70 85 1.25 1.20 1.15 VIN = 12V @ ISW = 0.65A 1.10 1.05 1.00 1.90 0.95 1.80 –40 0 25 TEMPERATURE (°C(T A)) 70 85 Figure 17. Switch-On Time vs. Temperature 0.90 –40 0 25 TEMPERATURE (°C(T A)) 70 85 Figure 20. Switch-On Voltage vs. Temperature in Step-Down Mode Rev. A | Page 7 of 16 00122-019 1.85 00122-016 ON TIME (µs) O 2.15 0.46 Figure 19. Saturation Voltage vs. Temperature in Step-Up Mode ON VOLTAGE (V) 2.25 VIN = 3V @ ISW = 0.65A 0.48 0.42 –40 Figure 16. Oscillator Frequency vs. Temperature 2.30 0.50 0.44 00122-015 350 0.52 00122-018 410 B SO OSCILLATOR FREQUENCY (kHz) 0.54 420 ADP3000 250 350 300 200 BIAS CURRENT (nA) BIAS CURRENT (nA) 250 150 100 200 150 100 50 25 TEMPERATURE (°C(T A)) 70 85 Figure 21. Feedback Bias Current vs. Temperature VIN = 20V 25 TEMPERATURE (°C(T A)) LE 500 400 300 0 25 TEMPERATURE (°C(T A)) 70 85 00122-021 B SO 200 Figure 22. Quiescent Current vs. Temperature O QUIESCENT CURRENT (µA) 600 0 –40 0 70 Figure 23. Set Pin Bias Current vs. Temperature 700 100 0 –40 Rev. A | Page 8 of 16 85 00122-022 0 TE 0 –40 00122-020 50 ADP3000 The ADP3000 is a versatile, high frequency, switch mode power supply (SMPS) controller. The regulated output voltage can be greater than the input voltage (in boost or step-up mode) or less than the input voltage (in buck or step-down mode). This device uses a gated oscillator technique to provide high performance with low quiescent current. The ADP3000 provides external connections for both the collector and the emitter of its internal power switch, permitting both step-up and step-down modes of operation. For the step-up mode, the emitter (Pin SW2) is connected to GND, and the collector (Pin SW1) drives the inductor. For stepdown mode, the emitter drives the inductor, while the collector is connected to VIN. The output voltage of the ADP3000 is set with two external resistors. Three fixed voltage models are also available: ADP3000-3.3 (3.3 V), ADP3000-5 (5 V), and ADP3000-12 (12 V). The fixed voltage models include laser-trimmed, voltage-setting resistors on the chip. On the fixed voltage models of the ADP3000, simply connect the feedback pin (Pin 8) directly to the output voltage. LE Figure 7 is a functional block diagram of the ADP3000. The internal 1.245 V reference is connected to one input of the comparator, and the other input is externally connected (via the FB pin) to a resistor divider, which is connected to the regulated output. When the voltage at the FB pin falls below 1.245 V, the 400 kHz oscillator turns on. The ADP3000 internal oscillator typically provides a 1.7 µs on time and a 0.8 µs off time. A driver amplifier provides base drive to the internal power switch, and the switching action raises the output voltage. When the voltage at the FB pin exceeds 1.245 V, the oscillator shuts off. While the oscillator is off, the ADP3000 quiescent current is only 500 µA. The comparator’s hysteresis ensures loop stability without requiring external components for frequency compensation. An uncommitted gain block on the ADP3000 can be connected as a low battery detector. The inverting input of the gain block is internally connected to the 1.245 V reference. The noninverting input is available at the SET pin. A resistor divider, connected between VIN and GND with the junction connected to the SET pin, causes the AO output to go low when the low battery set point is exceeded. The AO output is an open collector NPN transistor that can sink in excess of 300 µA. TE THEORY OF OPERATION O B SO The maximum current in the internal power switch is set by connecting a resistor between VIN and the ILIM pin. When the maximum current is exceeded, the switch is turned off. The current limit circuitry has a time delay of about 0.3 µs. If an external resistor is not used, connect ILIM to VIN. This yields the maximum feasible current limit. Further information on ILIM is included in the Applications Information section. Rev. A | Page 9 of 16 ADP3000 Table 5. Recommended Capacitors APPLICATIONS INFORMATION Vendor AVX Sanyo Sprague Panasonic Inductor Selection For most applications, the inductor used with the ADP3000 falls in the range of 4.7 µH to 33 µH. Table 4 shows recommended inductors and their vendors. When selecting an inductor for the ADP3000, it is very important to make sure the inductor is able to handle a current higher than the ADP3000’s current limit, without becoming saturated. In addition, inductor dc resistance causes power loss. To minimize power loss, it is best to use an inductor with a dc resistance lower than 0.2 Ω. Table 4. Recommended Inductors Series OCTAPAC UNIPAC CR43, CR54 CDRH6D28, CDRH73, CDRH64 Core Type Toroid Open Open Semi-Closed Geometry Phone Number (843) 448-9411 (619) 661-6835 (603) 224-1961 (800) 344-2112 Diode Selection The ADP3000’s high switching speed demands the use of Schottky diodes. Suitable choices include the 1N5817, the 1N5818, the 1N5819, the MBRS120LT3, and the MBR0520LT1. Fast recovery diodes are not recommended because their high forward drop lowers efficiency. General-purpose and smallsignal diodes should be avoided as well. PROGRAMMING THE SWITCHING CURRENT LIMIT The ADP3000’s RLIM pin permits the cycle-by-cycle switch current limit to be programmed with a single external resistor. This feature offers major advantages that ultimately decrease the component’s cost and the PCB’s real estate. First, the RLIM pin allows the ADP3000 to use low value, low saturation current and physically small inductors. Additionally, it allows for a physically small surface-mount tantalum capacitor with a typical ESR of 0.1 Ω. With this capacitor, it achieves an output ripple as low as 40 mV to 80 mV, as well as a low input ripple. Phone Number (561) 752-5000 (561) 752-5000 (847) 545-6700 (847) 545-6700 The current limit is usually set to approximately 3 to 5 times the full load current for boost applications, and about 1.5 to 3 times the full load current in buck applications. B SO Capacitor Selection For most applications, the capacitor used with the ADP3000 falls in the range of 33 µF to 220 µF. Table 5 shows recommended capacitors and their vendors. O For input and output capacitors, use low ESR type capacitors for best efficiency and lowest ripple. Recommended capacitors include the AVX TPS series, the Sprague 595D series, the Panasonic HFQ series, and the Sanyo OS-CON series. The internal structure of the ILIM circuit is shown in Figure 24. Q1, the ADP3000’s internal power switch, is paralleled by sense transistor Q2. The relative sizes of Q1 and Q2 are scaled so that IQ2 is 0.5% of IQ1. Current flows to Q2 through both the RLIM resistor and an internal 80 Ω resistor. The voltage on these two resistors biases the base-emitter junction of the oscillator-disable transistor, Q3. When the voltage across R1 and RLIM exceeds 0.6 V, Q3 turns on and terminates the output pulse. If only the 80 Ω internal resistor is used (when the ILIM pin is connected directly to VIN), the maximum switch current is 1.5 A. Figure 13, Figure 14, and Figure 15 give values for lower current limit levels. When selecting a capacitor, it is important to make sure the maximum capacitor ripple current rms rating is higher than the ADP3000’s rms switching current. It is best to protect the input capacitor from high turn-on current charging surges by derating the capacitor voltage by 2:1. For very low input or output voltage ripple requirements, use capacitors with very low ESR, such as the Sanyo OS-CON series. Alternatively, two or more tantalum capacitors can be used in parallel. RLIM (EXTERNAL) VIN VIN ILIM R1 Q3 ADP3000 400kHz OSCILLATOR 80Ω (INTERNAL) IQ1 200 DRIVER SW1 Q1 POWER SWITCH Q2 SW2 Figure 24. ADP3000 Current Limit Operation Rev. A | Page 10 of 16 00122-023 Vendor Coiltronics Coiltronics Sumida Sumida Type Surface Mount Through Hole Surface Mount Through Hole LE As a general rule, powdered iron cores saturate softly, whereas Ferrite cores saturate abruptly. Rod and open drum core geometry inductors saturate gradually. Inductors that saturate gradually are easier to use. Even though rod and drum core inductors are attractive in both price and physical size, they must be used with care because they have high magnetic radiation. When minimizing EMI is critical, toroid and closed drum core geometry inductors should be used. Series TPS OS-CON 595D HFQ TE COMPONENT SELECTION ADP3000 The ADP3000’s gain block can be used as a low battery detector, an error amplifier, or a linear post regulator. It consists of an op amp with PNP inputs and an open-collector NPN output. The inverting input is internally connected to the 1.245 V reference, and the noninverting input is available at the SET pin. The NPN output transistor sinks in excess of 300 µA. R1 = where: VL is the logic power supply voltage. RL is the pull-up resistor. RHYS creates the hysteresis. POWER TRANSISTOR PROTECTION DIODE IN STEP-DOWN CONFIGURATION When operating the ADP3000 in step-down mode with the switch off, the output voltage is impressed across the internal power switch’s emitter-base junction. When the output voltage is set to higher than 6 V, a Schottky diode must be placed in a series with SW2 to protect the switch. Figure 26 shows the proper way to place D2, the protection diode. The selection of this diode is identical to the step-down commuting diode (refer to the Diode Selection section). VIN V LOBATT − 1.245 V 1.245 V C2 + 1 where VLOBATT is the desired low battery trip point. B SO VIN 1.245V REF SET RL 47kΩ AO GND TO PROCESSOR Figure 25. Setting the Low Battery Detector Trip Point The circuit of Figure 25 may produce multiple pulses when approaching the trip point due to noise coupled into the SET input. To prevent multiple interrupts to the digital logic, add hysteresis to the circuit. Resistor RHYS, with a value of 1 MΩ to 10 MΩ, provides the hysteresis. The addition of RHYS alters the trip point slightly, changing the new value for R1 to L1 R2 SW2 4 5 D2 D1 C1 + R1 Figure 26. Step-Down Mode VOUT > 6.0 V THERMAL CONSIDERATIONS Power dissipation internal to the ADP3000 can be approximated with the following equations. Step-Up V IN I SW ⎤ ⎡ V IN ⎤ ⎡ 4 I O ⎤ ⎡ PD = ⎢ I SW 2 R + ⎥⎢ ⎥ + I Q [V IN ] ⎥ D ⎢1 − β VO ⎦ ⎣ I SW ⎦ ⎣ ⎦ ⎣ [ ] RHYS 1.6MΩ 00122-024 O R2 33kΩ V – 1.245V R1 = LB 37.7µA VLB = BATTERY TRIP POINT VOUT > 6V 3 FB 8 GND 5V ADP3000 2 VIN SW1 ADP3000 Because the gain block output is an open-collector NPN, a pull-up resistor should be connected to the positive logic power supply. R1 D1, D2 = 1N5818 SCHOTTKY DIODES R3 ILIM R2 VBATT ⎛ 1.245 V ⎞ ⎛⎜ VL − 1.245 V ⎞⎟ ⎜⎜ ⎟⎟ − ⎝ R2 ⎠ ⎜⎝ R L + R HYS ⎟⎠ LE Figure 25 shows the gain block configured as a low battery monitor. Set Resistors R1 and R2 to high values to reduce quiescent current, but not so high that bias current in the SET input causes large errors. A value of 33 kΩ for R2 is a good compromise. The value for R1 is then calculated as follows: VLOBATT − 1.245 V 00122-025 PROGRAMMING THE GAIN BLOCK R1 = TE The delay through the current limiting circuit is approximately 0.3 µs. If the switch-on time is reduced to less than 1.7 µs, accuracy of the current trip point is reduced as well. An attempt to program a switch-on time of 0.3 µs or less produces spurious responses in the switch-on time. However, the ADP3000 still provides a properly regulated output voltage. where: ISW is ILIMIT when the current limit is programmed externally; otherwise, ISW is the maximum inductor current. V0 is the output voltage. I0 is the output current. VIN is the input voltage. R is 1 Ω (typical RCE(SAT)). D is 0.75 (typical duty ratio for a single switching cycle). IQ is 500 µA (typical shutdown quiescent current). β = 30 (typical forced beta). Rev. A | Page 11 of 16 ADP3000 ⎡ PD = ⎢ I SW VCESAT ⎢⎣ ⎤⎡ 2 I O ⎛ VO 1 ⎞⎡ ⎜1 + ⎟ ⎢ ⎥⎢ ⎜ ⎟ β ⎠ ⎢⎣ V IN − VCE (SAT ) ⎦⎥ ⎣ I SW ⎝ ⎤ ⎤ ⎥ + I Q [V IN ]⎥ ⎥⎦ ⎦ [ ] where: ISW is ILIMIT when the current limit is programmed externally; otherwise, ISW is the maximum inductor current. VCE(SAT) is 1.2 V (typical value). Check this value by applying ISW to Figure 10. VO is the output voltage. IO is the output current. VIN is the input voltage. D is 0.75 (typical duty ratio for a single switching cycle). IQ is 500 µA (typical shutdown quiescent current). β is 30 (typical forced beta). ∆T = PD × θ JA Using the step-up power dissipation equation: (2)(0.8) ⎤ 2 ⎡ (4) 0.18 ⎤ ⎡ [0.75] ⎡⎢1 − ⎤⎥ ⎢ PD = ⎢0.8 2 × 1 + ⎥ + 500 E − 6 [2] ⎥ 30 ⎦ ⎣ 3.3 ⎦ ⎣ 0.8 ⎦ ⎣ [ ∆T is 185 mW (170°C/W) = 31.5°C, using the R-8 package. ∆T is 185 mW (120°C/W) = 22.2°C, using the N-8 package. At a 70°C ambient, the die temperature would be 101.45°C for the R-8 package and 92.2°C for the N-8 package. These junction temperatures are well below the maximum recommended junction temperature of 125°C. Finally, the die temperature can be decreased up to 20% by using a large metal ground plate as ground pickup for the ADP3000. O B SO where: ∆T is temperature rise. PD is device power dissipation. θJA is thermal resistance (junction-to-ambient). VIN is 2 V. VO is 3.3 V. IO is 180 mA. ISW is 0.8 A (externally programmed). LE The temperature rise can be calculated using the following equation: For example, consider a boost converter with the following specifications: TE Step-Down Rev. A | Page 12 of 16 ] ADP3000 TYPICAL APPLICATION CIRCUITS C1 + 100µF 10V IN5817 VOUT 3.3V 180mA 120Ω 1 2 ILIM VIN VIN 4.5V TO 5.5V L1 15µH C1 + 100µF 10V 1 2 ILIM VIN SW1 3 SW1 3 ADP3000-12V + SENSE 8 C2 100µF 10V SW2 GND SW2 5 4 5 4 Figure 27. 2 V to 3.3 V/180 mA Step-Up Converter Figure 30. 4.5 V to 12 V/50 mA Step-Up Converter VIN 5V TO 6V VOUT 5V 100mA 120Ω L1 = SUMIDA CR54-150 C1 = AVX TPS D107 M010R0100 C2 = AVX TPS D107 M016R0100 TYPICAL EFFICIENCY = 75% C1 100µF 10V 2 VIN + SENSE 8 SW2 5 4 C2 100µF 10V 00122-027 B SO GND L1 = SUMIDA CR43-6R8 C1, C2 = AVX TPS D107 M010R0100 TYPICAL EFFICIENCY = 80% IN5817 VOUT 5V 150mA 120Ω 1 2 ILIM VIN FB 8 SW2 4 5 D1 1N5817 VIN 10V TO 13V C1+ 33µF 20V SW2 5 4 C2 100µF 10V L1 = SUMIDA CR43-6R8 C1, C2 = AVX TPS D107 M010R0100 TYPICAL EFFICIENCY = 80% R1 110kΩ 1 2 ILIM 3 VIN SW1 SENSE 8 ADP3000-5V SW2 4 GND VOUT 5V 250mA L1 10µH 5 L1: SUMIDA CR43-100 C1 = AVX TPS D336 M020R0200 C2 = AVX TPS D107 M010R0100 TYPICAL EFFICIENCY = 77% D1 1N5817 + C2 100µF 10V 00122-028 O GND C2 + 100µF 10V 250Ω ADP3000-5V SENSE 8 VOUT 3V 100mA R2 150kΩ Figure 31. 5 V to 3 V/100 mA Step-Down Converter SW1 3 + L1 10µH GND L1 = SUMIDA CR43-100 C1, C2 = AVX TPS D107 M010R0100 TYPICAL EFFICIENCY = 75% Figure 28. 2 V to 5 V/100 mA Step-Up Converter L1 6.8µH 3 ADP3000-ADJ SW1 3 100µF 10V 2 VIN SW1 00122-030 1 ILIM C1 + 1 ILIM ADP3000-5V VIN 2.7V TO 4.5V 120Ω LE C1 + 100µF 10V C2 100µF 16V TE 00122-026 GND IN5817 + SENSE 8 L1 = SUMIDA CR43-6R8 C1, C2 = AVX TPS D107 M010R0100 TYPICAL EFFICIENCY = 75% VIN 2V TO 3.2V VOUT 12V 50mA 124Ω ADP3000-3.3V L1 6.8µH IN5817 00122-029 L1 6.8µH Figure 32. 10 V to 5 V/250 mA Step-Down Converter Figure 29. 2.7 V to 5 V/150 mA Step-Up Converter Rev. A | Page 13 of 16 00122-031 VIN 2V TO 3.2V ADP3000 VIN 5V C1 + 47µF 16V 240Ω 1 2 ILIM 3 VIN SW1 SENSE 8 ADP3000-5V SW2 4 GND L1 15µH 5 + D1 1N5817 VOUT –5V 100mA TE 00122-032 L1 = SUMIDA CR54-150 C1 = AVX TPS D476 M016R0150 C2 = AVX TPS D107 M010R0100 TYPICAL EFFICIENCY = 60% C2 100µF 10V 2.5V TO 4.2V 100kΩ LE Figure 33. 5 V to −5 V/100 mA Inverter (SUMIDA – CDRH62) 120Ω 330kΩ 6.8µH 2N2907 100µF + 10V AVX-TPS ILIM SET 1MΩ 1N5817 VIN 100kΩ SW1 33nF ADP3000 A0 FB 10kΩ IN1 348kΩ 1% 90kΩ + IN2 100µF 10V AVX-TPS ADP3302AR1 SD SW2 GND 200kΩ 1% 90kΩ Figure 34. 1 Cell Li-Ion to 3 V/200 mA Converter with Shut-Down at VIN ≤ 2.5 V @ VIN ≤ 2.5V SHDN IQ = 500µA IO = 50mA + 50mA 75 IO = 100mA + 100mA 65 2.6 3.0 3.4 3.8 4.2 Figure 35. Typical Efficiency of the Circuit of Figure 34 Rev. A | Page 14 of 16 VIN (V) 00122-034 O % EFFICIENCY 80 70 VO2 1µF 6V (MLC) 1µF 6V (MLC) 3V 100mA 3V 100mA 00122-033 B SO GND VO1 ADP3000 OUTLINE DIMENSIONS 0.375 (9.53) 0.365 (9.27) 0.355 (9.02) 8 5 1 4 0.295 (7.49) 0.285 (7.24) 0.275 (6.98) 0.325 (8.26) 0.310 (7.87) 0.300 (7.62) 0.100 (2.54) BSC 0.015 (0.38) MIN 0.150 (3.81) 0.130 (3.30) 0.110 (2.79) 0.022 (0.56) 0.018 (0.46) 0.014 (0.36) SEATING PLANE 0.060 (1.52) 0.050 (1.27) 0.045 (1.14) 0.015 (0.38) 0.010 (0.25) 0.008 (0.20) TE 0.180 (4.57) MAX 0.150 (3.81) 0.135 (3.43) 0.120 (3.05) COMPLIANT TO JEDEC STANDARDS MO-095AA CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN LE Figure 36. 8-Lead Plastic Dual In-Line Package [PDIP] (N-8) Dimensions shown in inches and (millimeters) 5.00 (0.1968) 4.80 (0.1890) 5 4 6.20 (0.2440) 5.80 (0.2284) B SO 8 4.00 (0.1574) 3.80 (0.1497) 1 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) 1.75 (0.0688) 1.35 (0.0532) 0.51 (0.0201) COPLANARITY SEATING 0.31 (0.0122) 0.10 PLANE 0.50 (0.0196) × 45° 0.25 (0.0099) 8° 0.25 (0.0098) 0° 1.27 (0.0500) 0.40 (0.0157) 0.17 (0.0067) O COMPLIANT TO JEDEC STANDARDS MS-012AA CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN Figure 37. 8-Lead Standard Small Outline Package [SOIC] Narrow Body (R-8) Dimensions shown in millimeters and (inches) Rev. A | Page 15 of 16 ADP3000 5.10 5.00 4.90 14 8 4.50 4.40 4.30 6.40 BSC 1 7 PIN 1 0.65 BSC 1.05 1.00 0.80 1.20 MAX 0.30 0.19 SEATING COPLANARITY PLANE 0.10 0.75 0.60 0.45 8° 0° TE 0.15 0.05 0.20 0.09 COMPLIANT TO JEDEC STANDARDS MO-153AB-1 ORDERING GUIDE Output Voltage Adjustable 3.3 V 5V 12 V Adjustable Adjustable 3.3 V 3.3 V 5V 5V 12 V 12 V Adjustable Adjustable Temperature Range –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C –40°C to +85°C O B SO Model ADP3000AN ADP3000AN-3.3 ADP3000AN-5 ADP3000AN-12 ADP3000AR ADP3000AR-REEL ADP3000AR-3.3 ADP3000AR-3.3-REEL ADP3000AR-5 ADP3000AR-5-REEL ADP3000AR-12 ADP3000AR-12-REEL ADP3000ARU ADP3000ARU-REEL LE Figure 38. 14-Lead Thin Shrink Small Outline Package [TSSOP] (RU-14) Dimensions shown in millimeters © 2004 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. C00122–0–9/04(A) Rev. A | Page 16 of 16 Package Description 8-lead plastic DIP 8-lead plastic DIP 8-lead plastic DIP 8-lead plastic DIP 8-lead SOIC 8-lead SOIC 8-lead SOIC 8-lead SOIC 8-lead SOIC 8-lead SOIC 8-lead SOIC 8-lead SOIC 14-lead TSSOP 14-lead TSSOP Package Option N-8 N-8 N-8 N-8 R-8 R-8 R-8 R-8 R-8 R-8 R-8 R-8 RU-14 RU-14