MAX649/MAX651/MAX652 19-0225 Rev 3 9/97 5V/3.3V/3V or Adjustable, High-Efficiency, Low I , Step-Down DC-DC Controllers Q General Description Features The MAX649/MAX651/MAX652 BiCMOS, step-down DC- More than 90% Efficiency (10mA to 1.5A Loads) DC switching controllers provide high efficiency over More than 12.5W Output Power three decades of load current. A unique, current-limited 100A Max Quiescent Supply Current pulse-frequency-modulated (PFM) control scheme gives these devices the benefits of pulse-width-modulation 5A Max Shutdown Supply Current (PWM) converters (high efficiency at heavy loads), while Less than 1.0V Dropout Voltage using only 100A of supply current (vs. 2mA to 10mA for 16.5V Max Input Voltage PWM converters). The result is high efficiency over loads ranging from 10mA to more than 2.5A. 5V (MAX649), 3.3V (MAX651), 3V (MAX652), or Adjustable Output Voltage These devices use miniature external components. Their high switching frequency (up to 300kHz) allows Current-Limited Control Scheme for less than 9mm diameter surface-mount inductors. Up to 300kHz Switching Frequency The MAX649/MAX651/MAX652 have dropout voltages less than 1V and accept input voltages up to 16.5V. Output voltages are preset at 5V (MAX649), 3.3V (MAX651), and 3V (MAX652). These controllers can Ordering Information also be adjusted to any voltage from 1.5V to the input voltage by using two resistors. PART TEMP. RANGE PIN-PACKAGE These step-down controllers drive external P-channel MAX649CPA 0C to +70C 8 Plastic DIP MOSFETs at loads greater than 10W. If less power is MAX649CSA 0C to +70C 8 SO required, use the MAX639/MAX640/MAX653 step-down MAX649C/D 0C to +70C Dice* converters with on-chip FETs, which allow up to a 225mA load current. MAX649EPA -40C to +85C 8 Plastic DIP MAX649ESA -40C to +85C 8 SO Applications MAX649MJA -55C to +125C 8 CERDIP** 5V-to-3.3V Green PC Applications Ordering Information continued at end of data sheet. * Dice are tested at T = +25C. High-Efficiency Step-Down Regulation A **Contact factory for availability and processing to MIL-STD-883. Minimum-Component DC-DC Converters Battery-Powered Applications Typical Operating Circuit Pin Configuration INPUT TOP VIEW 4V TO 16.5V V+ OUT 1 8 GND FB MAX651 2 7 EXT ON/OFF SHDN CS MAX649 SHDN 3 6 CS MAX651 EXT P MAX652 REF 4 OUTPUT 5 V+ 3.3V DIP/SO OUT REF FB GND Maxim Integrated Products 1 For free samples & the latest literature: 5V/3.3V/3V or Adjustable, High-Efficiency, Low I , Step-Down DC-DC Controllers Q ABSOLUTE MAXIMUM RATINGS Supply Voltage, V+ to GND.......................................-0.3V, +17V Operating Temperature Ranges REF, SHDN, FB, CS, EXT, OUT .......................-0.3V, (V+ + 0.3V) MAX649C A, MAX65 C A ..................................0C to +70C Continuous Power Dissipation (T = +70C) MAX649E A, MAX65 E A ................................-40C to +85C A Plastic DIP (derate 9.09mW/C above +70C) .............727mW MAX649MJA, MAX65 MJA ............................-55C to +125C SO (derate 5.88mW/C above +70C)..........................471mW Storage Temperature Range .............................-65C to +160C CERDIP (derate 8.00mW/C above +70C)..................640mW Lead Temperature (soldering, 10sec) .............................+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+ = 5V, T = T to T , unless otherwise noted. Typical values are at T = +25C.) A MIN MAX A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS V+ Input Voltage Range V+ 4.0 16.5 V V+ = 16.5V, SHDN 0.4V (operating, switch off) 80 100 Supply Current I V+ = 16.5V, SHDN 1.6V (shutdown) 4 A Q V+ = 10V, SHDN 1.6V (shutdown) 25 MAX649C, MAX65 C 1.470 1.5 1.530 FB Trip Point MAX649E, MAX65 E 1.4625 1.5 1.5375 V MAX649M, MAX65 M 1.455 1.5 1.545 MAX649C, MAX65 C 50 FB Input Current I MAX649E, MAX65 E 70 nA FB MAX649M, MAX65 M 90 MAX649, V+ = 6V to 16.5V 4.80 5.0 5.20 Circuit of Output Voltage V MAX651, V+ = 4V to 16.5V 3.17 3.3 3.43 V OUT Figure 1 MAX652, V+ = 4V to 16.5V 2.88 3.0 3.12 MAX649C, MAX65 C, IREF = 0 1.470 1.5 1.530 Reference Voltage V MAX649E, MAX65 E, I = 0 1.4625 1.5 1.5375 V REF REF MAX649M, MAX65 M, I = 0 1.455 1.5 1.545 REF MAX649C/E, MAX65 C/E 410 0 I 100A, REF REF Load Regulation mV sourcing only MAX649M, MAX65 M 415 REF Line Regulation 4V V+ 16.5V 40 100 V/V MAX649, 6V V+ 16V, 2.6 ILOAD = 1A Output Voltage Circuit of MAX651, 4.5V V+ 16V, 1.7 mV/V Line Regulation Figure 1 I = 1A LOAD MAX652, 4V V+ 16V, 1.9 ILOAD = 1A 2 MAX649/MAX651/MAX652