MAX1910/MAX1912 19-2290 Rev 2 3/04 1.5x/2x High-Efficiency White LED Charge Pumps General Description Features The MAX1910/MAX1912 power LEDs with a regulated High-Efficiency 1.5x/2x Charge Pumps output voltage or current (up to 120mA) from an unreg- Low Input Ripple with 750kHz Operation ulated input supply (2.7V to 5.3V). These are complete DC-DC converters requiring only four small ceramic 200mV Current-Sense Threshold Reduces capacitors and no inductors. Input ripple is minimized Power Loss by a unique regulation scheme that maintains a fixed Current- or Voltage-Regulated Charge Pump 750kHz switching frequency over a wide load range. Also included are logic-level shutdown and soft-start to Up to 120mA Output Current reduce input current surges at startup. No Inductors Required The MAX1910 has two automatically selected operating modes: 1.5x and 2x. 1.5x mode improves efficiency at Small Ceramic Capacitors higher input voltages, while 2x mode maintains regula- Regulated 5% LED Current tion at lower input voltages. The MAX1912 operates only in 1.5x mode. Load Disconnected in Shutdown The MAX1910 and the MAX1912 are available in a 1A Shutdown Current space-saving 10-pin MAX package. Small 10-Pin MAX Package Applications Ordering Information White LED Backlighting PART TEMP RANGE PIN-PACKAGE Cellular Phones MAX1910EUB -40C to +85C 10 MAX PDAs MAX1912EUB -40C to +85C 10 MAX Digital Still Cameras MP3 Players Backup-Battery Boost Converters Typical Operating Circuit Pin Configuration TOP VIEW V IN IN2 SHDN GND 1 10 SET IN1 OUT IN1 2 9 C1- C1+ MAX1910 C2- 3 8 IN2 C1 MAX1912 C IN C C1- OUT MAX1910 C1+ 4 7 C2+ MAX1912 OUT 5 6 SHDN C2+ SET C2 C2- MAX GND Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim s website at www.maxim-ic.com. EVALUATION KIT AVAILABLE1.5x/2x High-Efficiency White LED Charge Pumps ABSOLUTE MAXIMUM RATINGS Continuous Power Dissipation (T = +70C) IN1, IN2, OUT, SHDN, SET to GND -0.3V to +6V A 10-Pin MAX (derate 5.6 mW/C above +70C) ..........444mW C1-, C2-, to GND..................................................-0.3V, V + 1V IN C1+, C2+ to GND..........-0.3V, greater of V + 1V or V + 1V Operating Temperature Range ...........................-40C to +85C OUT IN OUT Short-Circuit to GND..........................................Continuous Storage Temperature Range .............................-65C to +150C Lead Temperature (soldering, 10s) ................................ +300C 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 = 3.6V, GND = 0, SHDN = SET = IN, C = 2.2F, C1 = C2 = 0.47F, C = 2.2F, T = 0C to +85C. Typical values are at IN IN OUT A T = +25C, unless otherwise noted.) A PARAMETER CONDITIONS MIN TYP MAX UNITS Input Voltage Operating Range 2.7 5.3 V Undervoltage Lockout Threshold Both rising and falling edges 2.2 2.5 V Undervoltage Lockout Hysteresis 35 mV SET Regulation Point 0.19 0.2 0.21 V MAX1910 Current Regulation Output current change for 2.7V < V < 5V 0.5 %/V OUT MAX1912 Current Regulation Output current change for 3V < V < 5V 0.5 %/V OUT MAX1910 V = 2.7V 80 IN Maximum Output Current mA MAX1912 V = 3.6V 120 IN No Load Input Current V =3.6V 1.5 2.5 mA IN Supply Current in Shutdown V = 5.3V, V = 0, SHDN = 0 0.1 10 A IN OUT Output Leakage Current in Shutdown V = 3.6V, SHDN = 0 0.1 10 A IN Switching Frequency V = 3.6V 625 750 875 kHz IN Switching Frequency Temperature f = 750kHz 250 ppm/C Coefficient SET Input Current 1 100 nA SHDN Input Current SHDN = 0 or 5.5V 1 A SHDN Input Voltage Low 2.7V < V < 5.3V 0.4 V IN SHDN Input Voltage High 2.7V < V < 5.3V 1.6 V IN Thermal-Shutdown Threshold Rising temperature, 15C hysteresis typical 160 C ELECTRICAL CHARACTERISTICS (V = 3.6V, GND = 0, SHDN = SET = IN, C = 2.2F, C1 = C2 = 0.47F, C = 2.2F, T = -40C to +85C, unless otherwise IN IN OUT A noted.) (Note 1) PARAMETER CONDITIONS MIN MAX UNITS Input Voltage Operating Range 2.7 5.3 V Undervoltage Lockout Threshold Both rising and falling edges 2.2 2.5 V MAX1910 V = 2.7V 80 IN Maximum Output Current mA MAX1910 V = 3.6V 120 IN Supply Current in Shutdown V = 5.3V, V = 0, SHDN = 0 10 A IN OUT 2 MAX1910/MAX1912