MAX608 19-0438 Rev 0 9/95 5V or Adjustable, Low-Voltage, Step-Up DC-DC Controller General Description Features The MAX608 low-voltage step-up controller operates 1.8V to 16.5V Input Range from a 1.8V to 16.5V input voltage range. Pulse-fre- 85% Efficiency for 30mA to 1.5A Load Currents quency-modulation (PFM) control provides high effi- ciency at heavy loads, while using only 85A (typical) Up to 10W Output Power when operating with no load. In addition, a logic-con- 110A Max Supply Current trolled shutdown mode reduces supply current to 2A typical. The output voltage is factory-set at 5V or can be 5A Max Shutdown Current adjusted from 3V to 16.5V with an external resistor Preset 5V or Adjustable Output (3V to 16.5V) divider. The MAX608 is ideal for two- and three-cell battery- Current-Limited PFM Control Scheme powered systems. An operating frequency of up to Up to 300kHz Switching Frequency 300kHz allows use with small surface-mount compo- nents. Evaluation Kit Available The MAX608 operates in bootstrapped mode only (with the chip supply, OUT, connected to the DC-DC output). For a 12V output without external resistors, or for nonbootstrapped applications (chip supply connect- ed to input voltage), refer to the pin-compatible MAX1771. The MAX608 is available in 8-pin DIP and SO packages. Applications Ordering Information High-Efficiency DC-DC Converters PART TEMP. RANGE PIN-PACKAGE Battery-Powered Applications MAX608C/D 0C to +70C Dice* Positive LCD-Bias Generators MAX608EPA -40C to +85C 8 Plastic DIP MAX608ESA -40C to +85C 8 SO Portable Communicators * Contact factory for dice specifications. Typical Operating Circuit Pin Configuration INPUT TOP VIEW 1.8V TO V OUT OUTPUT 5V EXT 1 8 CS MAX608 ON/OFF N SHDN EXT OUT 2 7 GND MAX608 REF FB 3 6 AGND CS SHDN 4 5 REF FB AGND GND OUT DIP/SO Maxim Integrated Products 1 Call toll free 1-800-998-8800 for free samples or literature. EVALUATION KIT MANUAL FOLLOWS DATA SHEET5V or Adjustable, Low-Voltage, Step-Up DC-DC Controller ABSOLUTE MAXIMUM RATINGS Supply Voltage Operating Temperature Range ...........................-40C to +85C OUT to GND.............................................................-0.3V, 17V Junction Temperature......................................................+150C EXT, CS, REF, SHDN, FB to GND ...............-0.3V, (VOUT + 0.3V) Storage Temperature Range .............................-65C to +160C GND to AGND.............................................................0.1V, -0.1V Lead Temperature (soldering, 10sec) .............................+300C Continuous Power Dissipation (TA = +70C) Plastic DIP (derate 9.09mW/C above +70C) ............727mW SO (derate 5.88mW/C above +70C).........................471mW 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 = 5V, I = 0mA, T = -40C to +85C where indicated. T = -25C to +85C for all other limits. Typical values are at OUT LOAD A A T = +25C.) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS TA = -25C to +85C 1.8 16.5 Input Voltage Range V (Note 2) T = -40C to +85C (Note 1) 1.9 16.5 A Minimum Start-Up Voltage No load 1.6 1.8 V T = -25C to +85C 85 110 V = 16.5V, A OUT m A SHDN 0.4V T = -40C to +85C (Note 1) 120 A Supply Current T = -25C to +85C 25 A V = 10V, OUT mA SHDN 1.6V T = -40C to +85C (Note 1) 10 A V = 2.0V to 5.0V, IN T = -25C to +85C 4.825 5.0 5.175 A Output Voltage (Note 3) over full load range, V T = -40C to +85C (Note 1) 4.800 5.0 5.200 circuit of Figure 2a A Output Voltage Line V = 2.7V to 4.0V, V = 5V, I = 500mA, IN OUT LOAD 7 mV/V Regulation (Note 4) circuit of Figure 2a Output Voltage Load V = 2V, V = 5V, I = 0mA to 500mA, IN OUT LOAD 60 mV/A Regulation (Note 4) circuit of Figure 2a m s Maximum Switch On-Time tON(max) 12 16 20 Minimum Switch Off-Time t (min) 1.8 2.3 2.8 m s OFF V = 4V, V = 5V, I = 500mA, IN OUT LOAD Efficiency 87 % circuit of Figure 2a T = -25C to +85C 1.4625 1.5 1.5375 A I 0m A Reference Voltage V REF = V REF TA = -40C to +85C (Note 1) 1.4475 1.5525 REF Load Regulation 0A I 100A -4 10 mV REF m V/V REF Line Regulation 3V V 16.5V 40 100 OUT T = -25C to +85C 1.4625 1.5 1.5375 A FB Trip Point Voltage V V FB (Note 5) TA = -40C to +85C (Note 1) 1.4475 1.5525 T = -25C to +85C -4 20 A FB Input Current I nA FB TA = -40C to +85C (Note 1) 40 SHDN Input High Voltage V V = 1.8V to 16.5V 1.6 V IH OUT SHDN Input Low Voltage VIL V = 1.8V to 16.5V 0.4 V OUT SHDN Input Current I V = 16.5V, SHDN = 0V or 16.5V 1 m A IN OUT 2 MAX608