ADP1109AR-5

a FEATURES Operates at Supply Voltages 2 V to 12 V Fixed 3.3 V, 5 V, 12 V and Adjustable Output Minimum External Components Required Ground Current: 320 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 ADP1109 FUNCTIONAL BLOCK DIAGRAMS VIN SENSE R2 250k COMPARATOR 1.25V REFERENCE + A1 120kHz OSCILLATOR DRIVER ADP1109-3.3: R1 = 152k ADP1109-5: R1 = 83k ADP1109-12: R1 = 29k SW Q1 R1 GND SHUTDOWN Fixed Output VIN FB ADP1109 COMPARATOR 1.25V REFERENCE + A1 120kHz OSCILLATOR DRIVER Q1 SW GENERAL DESCRIPTION The ADP1109 is a versatile step-up switching regulator. The device requires only minimal external components to operate as a complete switching regulator. The ADP1109-5 can deliver 100 mA at 5 V from a 3 V input and the ADP1109-12 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. VIN 5V GND SHUTDOWN Adjustable Output TYPICAL APPLICATION L1 33 H D1 VIN SW SENSE + C1 22 F 16V ADP1109-12 GND VOUT 12V 60mA SHUTDOWN SHUTDOWN/PROGRAM 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., 1998 ADP1109–SPECIFICATIONS (0 C ≤ T ≤ +70 C, V A IN = 3 V unless otherwise noted) Symbol IQ VIN 2 1.20 1.25 8 VOUT 3.13 4.75 11.45 3.30 5.00 12.00 16 20 40 fOSC DC tON VCESAT 0.4 0.4 0.4 1 VIH VIL 2.0 0.8 10 20 0.8 0.8 0.8 10 V V V µA V V µA µA 100 90 40 3.1 3.0 120 50 4.2 Min Typ 450 Max 590 9 1.30 14 3.46 5.25 12.55 40 50 110 140 155 70 5.9 6.5 Units µA V V mV V V V mV mV mV kHz kHz % µs µs Parameter QUIESCENT CURRENT INPUT VOLTAGE COMPARATOR TRIP POINT VOLTAGE COMPARATOR HYSTERESIS OUTPUT VOLTAGE ADP1109-3.3 ADP1109-5 ADP1109-12 OUTPUT VOLTAGE RIPPLE Conditions Switch Off ADP1109 2 V ≤ VIN ≤ 3 V 3 V ≤ VIN ≤ 5 V 3 V ≤ VIN ≤ 12 V ADP1109-3.3 ADP1109-5 ADP1109-12 TA = +25°C Full Load TA = +25°C ISW = 500 mA VIN = 3 V VIN = 3 V VIN = 5 V VSW = 12 V, TA = +25°C OSCILLATOR FREQUENCY DUTY CYCLE SWITCH-ON TIME SWITCH SATURATION VOLTAGE ADP1109-3.3 ADP1109-5 ADP1109-12 SWITCH LEAKAGE CURRENT SHUTDOWN PIN HIGH SHUTDOWN PIN LOW SHUTDOWN PIN INPUT CURRENT SHUTDOWN PIN INPUT CURRENT VSHUTDOWN = 2 V VSHUTDOWN = 0.8 V IIH IIL NOTES All limits at temperature extremes are guaranteed via correlation using standard quality control methods. Specifications subject to change without notice. L1 = CTX15-1 L1 15 H VIN = 2V 1N5818 +5V 300mA at 3V INPUT 50mA at 2V INPUT VIN = 2V L1 = CTX15-1 L1 15 H 1N5818 +12V 40mA at 3V INPUT 10mA at 2V INPUT + 10 F 20V VIN = 2V L1 = CTX15-1 L1 15 H 1N5818 +5V 300mA at 3V INPUT 50mA at 2V INPUT + 22 F 16V SW VIN SENSE SW VIN SENSE SW VIN SENSE ADP1109-12 SHUTDOWN GND SHUTDOWN ADP1109-5 GND + 22 F 16V ADP1109-12 GND Figure 1. 2 V to 5 V Converter Figure 2. 2 V to 12 V Converter Figure 3. 2 V to 5 V Converter With Shutdown – 2– REV. 0 ADP1109 ABSOLUTE MAXIMUM RATINGS* PIN CONFIGURATIONS 8-Lead Plastic DIP (N-8) 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. VIN 1 NC 2 8 FB(SENSE)* SHUTDOWN TOP VIEW SW 3 (Not to Scale) 6 NC 7 ADP1109A GND 4 5 NC ORDERING GUIDE NC = NO CONNECT *FIXED VERSIONS Model ADP1109AN ADP1109AR ADP1109AN-3.3 ADP1109AR-3.3 ADP1109AN-5 ADP1109AR-5 ADP1109AN-12 ADP1109AR-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 8-Lead SOIC (SO-8) VIN 1 8 FB(SENSE)* NC 2 ADP1109A 7 SHUTDOWN TOP VIEW SW 3 (Not to Scale) 6 NC GND 4 5 NC NC = NO CONNECT *FIXED VERSIONS PIN FUNCTION DESCRIPTIONS Pin 1 2, 5, 6 3 4 7 8 Mnemonic VIN NC SW GND SHUTDOWN FB(SENSE) Function Input Supply Voltage. No Connection. Collector Node of Power Transistor. Ground. 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 ADP1109-3.3, ADP1109-5 and ADP1109-12, this pin is connected through the internal resistor that sets the output voltage. 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 ADP1109 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– ADP1109 –Typical Performance Characteristics 123.5 OSCILLATOR FREQUENCY – kHz 123.0 122.5 122.0 121.5 121.0 120.5 120.0 119.5 119.0 118.5 2 4 6 8 10 12 14 16 INPUT VOLTAGE – V 18 20 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 SWITCH CURRENT – A 1 0 2 4 6 8 10 12 14 16 INPUT VOLTAGE – V 18 20 VCESAT – V A QUIESCENT CURRENT – DUTY CYCLE – % 1.0 0.8 500 400 1.2 600 0.6 0.4 300 200 0.2 100 Figure 4. Oscillator Frequency vs. Input Voltage Figure 5. Switch Saturation Voltage vs. Switch Current Figure 6. Quiescent Current vs. Input Voltage 150 OSCILLATOR FREQUENCY – kHz 4.5 4.4 58 56 54 52 50 48 46 44 42 –40 0 25 70 TEMPERATURE – C 85 140 130 SWITCH-ON TIME – s 0 25 70 TEMPERATURE – C 85 4.3 4.2 4.1 4.0 3.9 3.8 3.7 –40 120 110 100 90 –40 0 25 70 TEMPERATURE – C 85 Figure 7. Oscillator Frequency vs. Temperature Figure 8. Switch-On Time vs. Temperature Figure 9. Duty Cycle vs. Temperature 0.39 0.38 QUIESCENT CURRENT – 0 25 70 TEMPERATURE – C 85 0.37 VCE(SAT) – V 0.36 0.35 0.34 0.33 0.32 0.31 –40 A 600 500 400 300 200 100 0 –40 0 25 70 TEMPERATURE – C 85 Figure 10. Switch Saturation Voltage vs. Temperature Figure 11. Quiescent Current vs. Temperature –4– REV. 0 ADP1109 APPLICATION INFORMATION THEORY OF OPERATION The ADP1109 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 450 µA. A functional block diagram of the ADP1109 is shown on page 1. 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 ADP1109 quiescent current is only 450 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 ADP1109’s quiescent current will remain 450 µA. The output voltage of the ADP1109 is set with two external resistors. Three fixed-voltage models are also available: the ADP1109-3.3 (+3.3 V), ADP1109-5 (+5 V) and ADP1109-12 (+12 V). The fixed-voltage models are identical to the ADP1109, except that laser-trimmed voltage-setting resistors are included on the chip. On the fixed-voltage models of the ADP1109, simply connect the SENSE pin (Pin 8) directly to the output voltage. COMPONENT SELECTION General Notes on Inductor Selection The ADP1109 is designed for applications where the input voltage is fairly stable, such as generating +12 V from a +5 V logic supply. The ADP1109 does not have an internal switch current limiting circuit, so the inductor may saturate if the input voltage is too high. The ADP1111 or ADP3000 should be 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 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 stored in the inductor only while the ADP1109 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) When the ADP1109 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 ADP1109, 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 ADP1109 applications, an inductor of 10 µH to 47 µH, with a saturation current rating of 300 mA to 1 A and dc resistance