MAX750A/MAX758A 19-0195 Rev 0 10/93 Adjustable, Step-Down, Current-Mode PWM Regulators General Description Features The MAX750A/MAX758A are adjustable-output, CMOS, Up to 750mA Load Currents step-down, DC-DC switching regulators. The 160kHz High-Frequency, Current-Mode PWM MAX758A accepts inputs from 4V to 16V and delivers 85% to 96% Efficiencies 750mA, while the MAX750A accepts inputs from 4V to 33H or 100H Pre-Selected Inductor Value, 11V and delivers 450mA. Typical efficiencies are 85% No Component Design Required to 90%. Typical quiescent current is 1.7mA, or only 6A in shutdown mode. The output does not exhibit 1.7mA Quiescent Supply Current any ripple at subharmonics of the switching frequency 6A Shutdown Supply Current over its specified range. Adjustable Output Voltage Pulse-width-modulation (PWM) current-mode control Overcurrent, Soft-Start, and Undervoltage provides precise output regulation and excellent tran- Lockout Protection sient responses. Output voltage accuracy is guaran- Cycle-by-Cycle Current Limiting teed to be 4.5% plus feedback-resistor tolerance over line, load, and temperature variations. Fixed-frequency 8-Pin DIP/SO Packages (MAX750A) switching and absence of subharmonic ripple allows Ordering Information easy filtering of output ripple and noise, as well as the use of small external components. These regulators PART TEMP. RANGE PIN-PACKAGE require only a single inductor value to work in most MAX750ACPA 0C to +70C 8 Plastic DIP applications, so no inductor design is necessary. MAX750ACSA 0C to +70C 8 SO MAX750AC/D 0C to +70C Dice* Applications MAX750AEPA -40C to +85C 8 Plastic DIP Cellular Phones & Radios MAX750AESA -40C to +85C 8 SO Portable Communications Equipment MAX750AMJA -55C to +125C 8 CERDIP** Portable Instruments Ordering Information continued on last page. Computer Peripherals * Contact factory for dice specifications. **Contact factory for availability and processing to MIL-STD-883. Pin Configurations Typical Operating Circuit INPUT TOP VIEW 4V TO 16V OUTPUT ADJ. SHDN 1 8 V+ FROM REF 2 7 LX V+ 33H VREF TO V+ MAX750A SS 3 LX 6 GND MAX758A CC 4 5 I.C. MAX750A DIP MAX758A ON/OFF SHDN CC 1 V+ SHDN 8 REF 2 LX 7 REF MAX750A SS 3 6 GND SS GND 4 CC 5 I.C. SO Pin Configurations continued on last page. Maxim Integrated Products 1 Call toll free 1-800-998-8800 for free samples or literature.Adjustable, Step-Down, Current-Mode PWM Regulators ABSOLUTE MAXIMUM RATINGS Pin Voltages Operating Temperature Ranges: V+ (MAX750A).........................................................+12V, -0.3V MAX75 AC .......................................................0C to +70C V+ (MAX758A).........................................................+18V, -0.3V MAX75 AE ....................................................-40C to +85C LX (MAX750A) ....................................(V+ - 12V) to (V+ + 0.3V) MAX75 AMJA..................................................-55C to +125C LX (MAX758A) ....................................(V+ - 21V) to (V+ + 0.3V) Junction Temperatures: SS, CC, SHDN.............................................-0.3V to (V+ + 0.3V) MAX75 AC /AE ......................................................+150C Peak Switch Current (I ).........................................................2A LX MAX75 AMJA ................................................................+175C Reference Current (I ) ...................................................2.5mA REF Storage Temperature Range .............................-65C to +160C Power Dissipation (T = +70C) A Lead Temperature (soldering, 10sec) .............................+300C 8-Pin Plastic DIP (derate 9.09mW/C above +70C) .....727mW 8-Pin SO (derate 5.88mW/C above +70C)..................471mW 16-Pin Wide SO (derate 9.52mW/C above +70C) ......762mW 8-Pin CERDIP (derate 8.00mW/C above +70C)..........640mW 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 (Circuit of Figure 3, V+ = 9V for the MAX750A, V+ = 12V for the MAX758A, V = 5V, R2 = 40.20k, R3 = 13.0k, I = 0mA, OUT LOAD T = T to T , unless otherwise noted.) A MIN MAX MAX750A MAX758A PARAMETER CONDITIONS UNITS MIN TYP MAX MIN TYP MAX V+ = 6.0V to 11.0V 0mA < I < 450mA for MAX750AC, LOAD 4.75 5.00 5.25 0mA < I < 450mA for MAX750AE, LOAD 0mA < ILOAD < 300mA for MAX750AM Output Voltage V+ = 6.0V to 16.0V V (Note 1) 0mA < I < 450mA for MAX758AC/AE, 4.75 5.00 5.25 LOAD 0mA < I < 350mA for MAX758AM LOAD V+ = 10.2V to 16.0V, 4.75 5.00 5.25 0mA < I < 750mA LOAD Input Voltage Range 4.0 11.0 4.0 16.0 V V+ = 4.0V to 11.0V 0.15 Line Regulation %/V V+ = 4.0V to 16.0V 0.15 I = 0mA to 450mA 0.0005 LOAD Load Regulation %/mA ILOAD = 0mA to 750mA 0.0005 V+ = 9.0V, I = 300mA 92 90 LOAD Efficiency % V+ = 12V, I = 750mA 87 LOAD Supply Current 1.7 3.0 1.7 3.0 mA Shutdown Supply SHDN = 0V 6.0 100.0 6.0 100.0 A Current (Note 2) VIH 2.0 2.0 Shutdown Input V Threshold V 0.25 0.25 IL Shutdown Input 1.0 1.0 A Leakage Current Short-Circuit Current 1.5 1.5 A 2 MAX750A/MAX758A