ADVANCE INFORMATION All information in this data sheet is preliminary and subject to change. 897 MM AXLAA Regulated, 125mA-Output, Charge-Pump DC-DC Inverter Generali Description The MAX1673 charge-pump inverter provides a low- cost and compact means of generating a regulated negative output from a positive input at up to 125mA. Its equivalent output resistance is only 6Q. The MAX1673 comes in an 8-pin SO and requires only three small capacitors and two resistors to set its output volt- age. The input range is 2V to 5.5V. The regulated out- put can be set from (-1 x Vin) to OV in skip mode or from (-1 x Vin) to -1.5V in linear mode. The MAX1673 can be configured to regulate in one of two ways: in skip mode or in linear mode. In skip mode, the MAX1673 regulates by varying its switching fre- quency as a function of the load current. This patented on-demand switching gives the MAX1673 two advan- tages: very smail capacitors and very low quiescent supply current. For example, at heavy loads, it transfers energy from the input to the output by switching at up to 350kHz, requiring only small 2.2uF capacitors. At light loads, it switches more slowly, using only 45uA quiescent supply current. In linear mode, the MAX1673 switches at a constant 350kHz and regulates its output by controlling the cur- rent-path resistance. The output ripple's constant fre- quency allows it to be easily filtered for low-noise applications. The MAX1673 also features a 1pA logic-controlled shut- down. For a smalier device that delivers about 30mA and fits in a smaller package, refer to the MAX868. Applications Hard Disk Drives Analog Signal-Processing Applications Measurement Instruments Modems Camcorders Digital Cameras AAAXLMM Features # Regulated Negative Output Voitage (Up to -1 x Vin) @ 125mA Output Current (62 output impedance) 45yA Quiescent Supply Current (skip-mode regulation) @ 350kHz Fixed-Frequency, Low-Noise Output (linear mode) # 2V to 5.5V Input Range @ 1pA Logic-Controlied Shutdown Ordering Information PART TEMP.RANGE _ PIN-PACKAGE MAX1673C/D OCto+70C Dice" MAX1673ESA -40C to +85C gso *Dice are tested at TA = +25C, DC parameters only. Typical Operating Circuit INPUT 2vTO55V | + ~ VIN REGULATED ON ope P| SHON FB NEGATIVE OUTPUT MAAXIAN UP TO-1xVm MAX1673 UP TO 125mA GUT iF CAP+ + TH] ww. i LIN/SKIP__GND Maxim Integrated Products 4-233 For free samples & the latest literature: http//www.maxim-ic.com, or phone 1-800-998-8800. For small orders, phone 408-737-7600 ext. 3468. EZLOLXVINMA1673 Regulated, 125mA-Output Charge-Pump DC-DC Inverter ____Pin Configuration TOP VIEW uNsKiP [7 | a} vin caps [2 | AAAXLAA TT) ono EB MAX1673 4) cap- [3 | 6] FB sow [4 rs] our 8SO 4.234 PRAAXLAR