ADP1073 Datasheet | Analog Devices

a Features Operates at Supply Voltages from 1.0 V to 30 V Ground Current 100 ␮A Works in Step-Up or Step-Down Mode Very Few External ponents Required Low Battery Detector On-Chip User-Adjustable Current Limit Internal 1 A Power Switch Fixed and Adjustable Output Voltage Versions 8-Lead DIP or SO-8 Package APPLICATIONS Single-Cell to 5 V Converters Laptop and Palmtop puters Pagers Cameras Battery Backup Supplies Cellular Telephones Portable Instruments 4 m A- 20 m A Loop Powered Instruments Hand-Held Inventory puters Micropower DC- DC Converter Adjustable and Fixed 3.3 V, 5 V, 12 V ADP1073 FUNCTIONAL BLOCK DIAGRAMS A2 VIN GAIN BLOCK/ ERROR AMP 212m V REFERENCE ILIM SW1 A1 OSCILLATOR DRIVER SW2 AO PARATOR GND FB ADP1073-3.3 ADP1073-5 ADP1073-12 VIN A2 GAIN BLOCK/ ERROR AMP 212m V REFERENCE A1 OSCILLATOR DRIVER SW2 AO ILIM SW1 GENERAL DESCRIPTION The ADP1073 is part of a family of step-up/step-down switching regulators that operates from an input supply voltage of as little as 1.0 V. This extremely low input voltage allows the ADP1073 to be used in applications requiring use of a single cell battery as the primary power source. The ADP1073 can be configured to operate in either step-up or step-down mode but for input voltages greater than 3 V, the ADP1173 is remended. An auxiliary gain amplifier can serve as a low battery detector or linear regulator. Quiescent current on the ADP1073-5 is only 100 µA unloaded, making it ideal for systems where long battery life is required. The ADP1073 can deliver 40 m A at 5 V from an input voltage range as low as 1.25 V, or 10 m A at 5 V from a 1.0 V input. Current limiting is available by adding an external resistor. R1 PARATOR R2 904k⍀ ADP1073-3.3: R1 = 62.1k⍀ ADP1073-5: R1 = 40k⍀ ADP1073-12: R1 = 16.3k⍀ SENSE ADP1073-3.3, 5, 12 REV. 0 Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its...