ADP1109AAR

a FEATURES Operates at Supply Voltages 2 V to 9 V Fixed 3.3 V, 5 V, 12 V and Adjustable Output Minimum External Components Required Ground Current: 460 A Oscillator Frequency: 120 kHz Logic Shutdown 8-Lead DIP and SO-8 Packages APPLICATIONS Cellular Telephones Single-Cell to 5 V Converters Laptop and Palmtop Computers Pagers Cameras Battery Backup Supplies Portable Instruments Laser Diode Drivers Hand-Held Inventory Computers Micropower Low Cost Fixed 3.3 V, 5 V, 12 V and Adjustable DC-to-DC Converter ADP1109A FUNCTIONAL BLOCK DIAGRAM VIN SENSE R2 250k COMPARATOR 1.25V REFERENCE A1 120kHz OSCILLATOR DRIVER Q1 ADP1109A-3.3: R1 = 152k ADP1109A-5: R1 = 83k ADP1109A-12: R1 = 29k SW R1 GND SHUTDOWN PGND VIN FB ADP1109A COMPARATOR SW 120kHz OSCILLATOR DRIVER GENERAL DESCRIPTION 1.25V REFERENCE A1 Q1 The ADP1109A is a versatile step-up switching regulator. The device requires only minimal external components to operate as a complete switching regulator. The ADP1109A-5 can deliver 100 mA at 5 V from a 3 V input and the ADP1109A-12 can deliver 60 mA at 12 V from a 5 V input. The device also features a logic controlled shutdown capability that, when a logic low is applied, will shut down the oscillator. The 120 kHz operating frequency allows for the use of small surface mount components. The gated oscillator capability eliminates the need for frequency compensation. GND SHUTDOWN PGND TYPICAL APPLICATION L1 33 H D1 3 VIN 5V 1 VIN SW SENSE 8 ADP1109A-12 7 VOUT 12V 60mA SHUTDOWN PGND GND 4 5 + SHUTDOWN/PROGRAM C1 22 F 16V Flash Memory VPP Generator R EV. 0 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 which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 1997 ADP1109A–SPECIFICATIONS (0 C ≤ T ≤ 70 C, V A IN = 3 V unless otherwise noted) VS IQ VIN 2 1.20 1.25 8 VOUT 3.13 4.75 11.45 3.30 5.00 12.00 15 25 60 fOSC 95 57 3.8 120 67 5.6 0.4 0.4 0.4 1 VIH VIL 2.0 0.8 10 20 Min Typ 460 Max 580 9 1.30 12.5 3.47 5.25 12.55 35 50 120 155 77 7.4 0.8 0.8 0.8 10 Units µA V V mV V V V mV mV mV kHz % µs V V V µA V V µA µA Parameter QUIESCENT CURRENT INPUT VOLTAGE COMPARATOR TRIP POINT VOLTAGE COMPARATOR HYSTERESIS OUTPUT VOLTAGE ADP1109A-3.3 ADP1109A-5 ADP1109A-12 OUTPUT VOLTAGE RIPPLE Conditions Switch Off ADP1109A 2 V ≤ VIN ≤ 3 V 2 V ≤ VIN ≤ 5 V 2 V ≤ VIN ≤ 9 V ADP1109A-3.3 ADP1109A-5 ADP1109A-12 OSCILLATOR FREQUENCY DUTY CYCLE SWITCH-ON TIME SWITCH SATURATION VOLTAGE ADP1109A-3.3 ADP1109A-5 ADP1109A-12 SWITCH LEAKAGE CURRENT SHUTDOWN PIN HIGH SHUTDOWN PIN LOW SHUTDOWN PIN INPUT CURRENT SHUTDOWN PIN INPUT CURRENT VSHUTDOWN = 4 V VSHUTDOWN = 0 V ISW = 500 mA VIN = 3 V VIN = 3 V VIN = 3 V VSW = 9 V, TA = +25°C Full Load DC tON VCESAT IIH IIL NOTES All limits at temperature extremes are guaranteed via correlation using standard quality control methods. Specifications subject to change without notice. ABSOLUTE MAXIMUM RATINGS* Supply Voltage, VOUT . . . . . . . . . . . . . . . . . . . . –0.4 V to 20 V SW Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . –0.4 V to 50 V Shutdown Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . 6.0 V Switch Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.2 A Maximum Power Dissipation . . . . . . . . . . . . . . . . . . 300 mW Operating Temperature Range . . . . . . . . . . . . 0°C to +70°C Storage Temperature Range . . . . . . . . . . . . –65°C to +150°C Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . +300°C *This is a stress rating only; operation beyond these limits can cause the device to be permanently damaged. – 2– REV. 0 ADP1109A PIN FUNCTION DESCRIPTIONS PIN CONFIGURATIONS 8-Lead Plastic DIP (N-8) VIN 1 NC 2 8 Pin Mnemonic 1 2 3 4 5 6 7 8 VIN NC SW PGND GND NC SHUTDOWN FB(SENSE) Function Input Supply Voltage. No Connection. Collector Node of Power Transistor. Power Ground. Ground. No Connection. When logic low is applied to this pin, oscillator is shut down. On the ADP1109A (Adjustable), this pin goes directly to the comparator input. On the ADP1109A-3.3, ADP1109A-5 and ADP1109A-12, this pin is connected through the internal resistor that sets the output voltage. ORDERING GUIDE FB(SENSE)* SHUTDOWN TOP VIEW SW 3 (Not to Scale) 6 NC PGND 4 5 ADP1109A 7 GND *FIXED VERSIONS NC = NO CONNECT 8-Lead SOIC (SO-8) VIN 1 NC 2 SW 3 PGND 4 8 FB(SENSE)* SHUTDOWN NC GND ADP1109A TOP VIEW (Not to Scale) 7 6 5 Model ADP1109AAN ADP1109AAR ADP1109AAN-3.3 ADP1109AAR-3.3 ADP1109AAN-5 ADP1109AAR-5 ADP1109AAN-12 ADP1109AAR-12 Output Voltage ADJ ADJ 3.3 V 3.3 V 5V 5V 12 V 12 V Package Description Plastic DIP Small Outline IC Plastic DIP Small Outline IC Plastic DIP Small Outline IC Plastic DIP Small Outline IC Package Options N-8 SO-8 N-8 SO-8 N-8 SO-8 N-8 SO-8 *FIXED VERSIONS NC = NO CONNECT CAUTION 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 the ADP1109A 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. WARNING! ESD SENSITIVE DEVICE REV. 0 –3– ADP1109A 2k 20 H* VIN 3.3V 22 F + 3 1 MBRS130T3 12V 60mA VIN 5V + 10 H* 22 F MBRS130T3 2N4403 3 VIN SW SENSE 8 1 VIN SW SENSE 8 ADP1109A-12 7 ADP1109A-12 7 SHUTDOWN GND PGND 5 4 + SHUTDOWN GND PGND 5 4 VOUT 12V 110mA + + 33 F** 25V SHUTDOWN 47 F** 20V 1F SHUTDOWN *COILTRONICS CTX20-1 SUMIDA CD54-220LC **AVX TPS SERIES *COILTRONICS CTX33-2 SUMIDA CD54-330LC **AVX TPS SERIES Figure 1. 3.3 V Powered Flash Memory VPP Generator Figure 4. 5 V to 12 V Converter With Shutdown to 0 V at Output L1 33 H* MBRS130T3 10 H* VIN 2V 22 F + 3 1 MBRS130T3 12V 35mA 3 VIN SW SENSE 8 ADP1109A-12 7 VIN 3V 1 VIN SW FB 8 R2 250k R1 40.3k + ADP1109A 7 VOUT 9V SHUTDOWN GND PGND 5 4 SHUTDOWN GND GND 5 4 + 33 F** 25V SHUTDOWN SHUTDOWN *COILTRONICS CTX10-1 SUMIDA CD54-100LC **AVX TPS SERIES C1 22 F** 16V *COILTRONICS CTX33-2 SUMIDA CD54-330LC **AVX TPS SERIES Figure 2. 2 V Powered Flash Memory VPP Generator Figure 5. 3 V to 9 V Converter 10 H* VIN 2V 22 F + 3 1 MBRS130T3 5V 110mA VIN SW SENSE 8 ADP1109A-5 7 SHUTDOWN GND PGND 5 4 + 33 F** 10V SHUTDOWN *COILTRONICS CTX10-1 SUMIDA CD54-100LC **AVX TPS SERIES Figure 3. 2 V to 5 V Converter –4– REV. 0 ADP1109A 170 OSCILLATOR FREQUENCY – kHz 68 1.4 1.2 SATURATION VOLTAGE – V 150 DUTY CYCLE – % 65 1.0 0.8 0.6 0.4 0.2 130 VIN = 5V VIN = 3V 62 110 59 90 VIN = 2V 70 50 –40 56 0 25 70 TEMPERATURE – C 85 53 –40 0 25 70 TEMPERATURE – C 85 0.0 0.1 0.2 0.4 0.6 0.8 ISWITCH CURRENT – A 1 1.2 Figure 6. Oscillator Frequency vs. Temperature Figure 7. Duty Cycle vs. Temperature Figure 8. Saturation Voltage vs. ISWITCH Current in Step-Up Mode 0.60 0.55 0.50 0.45 VCE(SAT) – V 6.0 VCE(SAT) @ VIN = 3V AND ISW = 0.65A SWITCH-ON TIME – sec 600 550 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 –40 0 25 70 TEMPERATURE – C 85 QUIESCENT CURRENT – A 500 450 400 350 300 250 –40 0.40 0.35 0.30 0.25 0.20 0.15 0.10 –40 0 25 70 TEMPERATURE – C 85 0 25 70 TEMPERATURE – C 85 Figure 9. Switch Saturation Voltage vs. Temperature Figure 10. Switch-On Time vs. Temperature Figure 11. Quiescent Current vs. Temperature 12.20 12.15 12.10 OUTPUT VOLTAGE – V QUIESCENT CURRENT – A 600 500 12.05 12.00 11.95 11.90 11.85 11.80 11.75 11.70 –40 0 25 70 TEMPERATURE – C 85 400 300 200 2 4 6 8 10 12 14 16 INPUT VOLTAGE – Volts 18 20 Figure 12. 12 V Output Voltage vs. Temperature Figure 13. Quiescent Current vs. Input Voltage REV. 0 –5– ADP1109A APPLICATION INFORMATION THEORY OF OPERATION considered for battery powered and similar applications where the input voltage varies. To minimize Electro-Magnetic Interference (EMI), a toroid or pot core type inductor is recommended. Rod core inductors are a lower-cost alternative if EMI is not a problem. Calculating the Inductor Value The ADP1109A is a flexible, low power switch-mode power supply (SMPS) controller for step-up dc/dc converter applications. This device uses a gated-oscillator technique to provide very high performance with low quiescent current. For example, more than 2 W of output power can be generated from a +5 V source, while quiescent current is only 360 µA. A functional block diagram of the ADP1109A is shown on the front page. The internal 1.25 V reference is connected to one input of the comparator, while the other input is externally connected (via the FB pin) to a feedback network connected to the regulated output. When the voltage at the FB pin falls below 1.25 V, the 120 kHz oscillator turns on. 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 1.25 V, the oscillator is shut off. While the oscillator is off, the ADP1109A quiescent current is only 460 µA. The comparator includes a small amount of hysteresis, which ensures loop stability without requiring external components for frequency compensation. A shutdown feature permits the oscillator to be shut off. Holding SHUTDOWN low will disable the oscillator, and the ADP1109A’s quiescent current will remain 460 µA. The output voltage of the ADP1109A is set with two external resistors. Three fixed-voltage models are also available: the ADP1109A-3.3 (+3.3 V), ADP1109A-5 (+5 V) and ADP1109A-12 (+12 V). The fixed-voltage models are identical to the ADP1109A, except that laser-trimmed voltage-setting resistors are included on the chip. On the fixed-voltage models of the ADP1109A, simply connect the SENSE pin (Pin 8) directly to the output voltage. COMPONENT SELECTION General Notes on Inductor Selection Selecting the proper inductor value is a simple two step process: 1. Define the operating parameters: minimum input voltage, maximum input voltage, output voltage and output current. 2. Calculate the inductor value, using the equations in the following section. Inductor Selection In a step-up, or boost, converter (Figure 1), the inductor must store enough power to make up the difference between the input voltage and the output voltage. The inductor power is calculated from the equation: P L = VOUT + V D − VIN ( MIN ) × IOUT ( )( ) (1) where VD is the diode forward voltage ( 0.5 V for a 1N5818 Schottky). Energy is only stored in the inductor while the ADP1109A switch is ON, so the energy stored in the inductor on each switching cycle must be must be equal to or greater than: PL f OSC (2) in order for the ADP1109A to regulate the output voltage. When the internal power switch turns ON, current flow in the inductor increases at the rate of: IL t = When the ADP1109A internal power switch turns on, current begins to flow in the inductor. Energy is stored in the inductor core while the switch is on, and this stored energy is then transferred to the load when the switch turns off. To specify an inductor for the ADP1109A, the proper values of inductance, saturation current and dc resistance must be determined. This process is not difficult, and specific equations are provided in this data sheet. In general terms, however, the inductance value must be low enough to store the required amount of energy (when both input voltage and switch ON time are at a minimum) but high enough that the inductor will not saturate when both VIN and switch ON time are at their maximum values. The inductor must also store enough energy to supply the load, without saturating. Finally, the dc resistance of the inductor should be low, so that excessive power will not be wasted by heating the windings. For most ADP1109A applications, an inductor of 10 µH to 47 µH, with a saturation current rating of 300 mA to 1 A and dc resistance