EVALUATION KIT AVAILABLE MAX1640/MAX1641 Adjustable-Output, Switch-Mode Current Sources with Synchronous Rectifier General Description Features The MAX1640/MAX1641 CMOS, adjustable-output, 95% Efficiency switch-mode current sources operate from a +5.5V to +5.5V to +26V Input Supply Range +26V input, and are ideal for microprocessor-controlled battery chargers. Charging current, maximum output 2V to 24V Adjustable-Output Voltage Range voltage, and pulse-trickle charge are programmed with 100% Maximum Duty Cycle (Low Dropout) external resistors. Programming the off-time modifies the switching frequency, suppressing undesirable har- Up to 500kHz PWM Operation monics in noise-sensitive circuits. The MAX1640s high- Optional Synchronous Rectifier side current sensing allows the load to connect directly to ground, eliminating ground-potential errors. The 16-Pin QSOP Package MAX1641 incorporates a low-side current sense. Current-Sense Accuracy: 2% (MAX1641) The MAX1640/MAX1641 step-down pulse-width-modu- 5.3% (MAX1640) lation (PWM) controllers use an external P-channel MOSFET switch and an optional, external N-channel MOSFET synchronous rectifier for increased efficiency. An internal low-dropout linear regulator provides power Ordering Information for the internal reference and circuitry as well as the gate drive for the N-channel synchronous rectifier. PART TEMP RANGE PIN-PACKAGE The MAX1640/MAX1641 are available in space-saving, MAX1640C/D 0C to +70C Dice* 16-pin narrow QSOP packages. MAX1640EEE+ -40C to +85C 16 QSOP MAX1641C/D 0C to +70C Dice* Applications MAX1641EEE+ -40C to +85C 16 QSOP Battery-Powered Equipment *Dice are specified at T = +25C, DC parameters only. A Laptop, Notebook, and Palmtop Computers +Denotes a lead(Pb)-free/RoHS-compliant package. Handy Terminals Portable Consumer Products Typical Operating Circuit Cordless Phones Cellular Phones V = +5.5V TO +26V Functional Diagrams IN PCS Phones IN LDOH Backup Battery Charger D0 PDRV P D1 Pin Configuration TOFF NDRV R TOFF TOP VIEW REF PGND + LDOL 1 16 IN CS+ TOFF 2 15 LDOH SET D1 3 14 PDRV OUT CS- D0 4 MAX1640 13 NDRV MAX1641 CC 5 12 PGND MAX1640 REF 6 11 CS+ TERM CC SET 7 10 CS- GND LDOL TERM 8 9 GND Pin Configurations appear at end of data sheet. Functional Diagrams continued at end of data sheet. QSOP UCSP is a trademark of Maxim Integrated Products, Inc. For pricing, delivery, and ordering information, please contact Maxim Direct 19-1245 Rev 2 5/09 at 1-888-629-4642, or visit Maxims website at www.maxim integrated.com. AVAILABLEMAX1640/MAX1641 Adjustable-Output, Switch-Mode Current Source with Synchronous Rectifier ABSOLUTE MAXIMUM RATINGS IN to GND...............................................................-0.3V to +28V Continuous Power Dissipation (T = +70C) A LDOH to IN...............................................................+0.3V to -6V QSOP (derate 9.6mW/C above +70C)..................... 772mW LDOL to GND ...........................................................-0.3V to +6V Package Junction-to-Ambient Thermal Resistance ( ) JA PDRV to GND .............................. (V - 0.3V) to (V + 0.3V) (Note 1) ..................................................................103.7C/W LDOH IN NDRV to GND .........................................-0.3V to (V + 0.3V) Package Junction-to-Case Thermal Resistance ) LDOL JC TOFF, REF, SET, TERM, CC to GND ......-0.3V to (V + 0.3V) (Note1) ....................................................................... 37C/W LDOL D0, D1 to GND .........................................................-0.3V to +6V Operating Temperature Range CS+, CS- to GND ...................................................-0.3V to +28V MAX164 EEE...................................................-40C to +85C PGND to GND.....................................................................0.3V Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10sec) ............................ +300C Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four- layer board. For detailed information on package thermal comsiderations, refer to www.maxim-ic.com/thermal-tutorial. Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ELECTRICAL CHARACTERISTICS (V = +12V, V = 6V, Circuit of Figure 1, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) IN OUT A A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS Input Voltage Range V 5.5 26 V IN Linear-Regulator Output V-V-V - IN IN IN V V = 5.5V to 26V, I = 0 to 20mA V LDOH IN LOAD Voltage, V Referenced 5.5 5.0 4.5 IN Linear-Regulator Output V V = 5.5V to 26V, I = 0 to 20mA 4.5 5.0 5.5 V LDOL IN LOAD Voltage, Ground Referenced MAX1640 142 150 158 Full-Scale Current-Sense mV Threshold MAX1641 147 150 153 MAX1640 36 42 48 Quarter-Scale Current-Sense mV Threshold MAX1641 34 37.5 41 Current-Sense Line Regulation V = V + 0.5V to 26V 0.03 %/V IN OUT MAX1640 0.1 0.4 Output Current Compliance V = 2V to 24V %/V OUT MAX1641 0.1 D0 or D1 = high 24 mA Quiescent V Supply Current IN D0 = D1 = low (off mode) 500 A Output Current in Off Mode D0 = D1 = low 1 A V Undervoltage Lockout 4.05 4.20 4.35 V LDOL Reference Voltage V 1.96 2.00 2.04 V REF Reference Load Regulation I = 0 to 50A 410 mV REF V Input Current 1 A SET FET Drive Output Resistance PFET and NFET drive 12 Off-Time Range 110 s Off-Time Accuracy R = 62k 1.7 2.2 2.7 s TOFF Pulse-Trickle Mode Duty-Cycle D0 = low, D1 = high, R = 100k 27 33 40 ms TOFF Period Pulse-Trickle Mode Duty Cycle D0 = low, D1 = high, R = 100k 12.5 % TOFF (Note 2) 2 Maxim Integrated