MAX5070/MAX5071 19-3283 Rev 3 10/06 High-Performance, Single-Ended, Current-Mode PWM Controllers General Description Features The MAX5070/MAX5071 BiCMOS, high-performance, Pin-for-Pin Replacement for UC2842 (MAX5070A) current-mode PWM controllers have all the features and UC2844 (MAX5070B) required for wide input voltage range isolated/nonisolated 2A Drive Source and 1A Sink Capability power supplies. These controllers are used for low- and high-power universal input voltage and telecom power Up to 1MHz Switching Frequency Operation supplies. Bidirectional Synchronization The MAX5070/MAX5071 contain a fast comparator with (MAX5071A/MAX5071B) only 60ns typical delay from current sense to the output Advanced Output Drive for Secondary-Side for overcurrent protection. The MAX5070A/MAX5070B Synchronous Rectification (MAX5071C) have an integrated error amplifier with the output at COMP. Soft-start is achieved by controlling the COMP Fast 60ns Cycle-by-Cycle Current Limit voltage rise using external components. Trimmed Oscillator Capacitor Discharge Current The frequency is adjustable from 20kHz to 1MHz with Sets Maximum Duty Cycle Accurately an external resistor and capacitor. The timing capacitor discharge current is trimmed allowing for programma- Accurate 5% Start and Stop Voltage with 6V ble dead time and maximum duty cycle for a given fre- Hysteresis quency. The available saw-toothed waveform at R C T T Low 32A Startup Current can be used for slope compensation when needed. 5V Regulator Output (VREF) with 20mA Capability The MAX5071A/MAX5071B include a bidirectional syn- chronization circuit allowing for multiple controllers to Overtemperature Shutdown run at the same frequency to avoid beat frequencies. Ordering Information Synchronization is accomplished by simply connecting the SYNC pins of all devices together. When synchro- PART TEMP RANGE PIN-PACKAGE nizing with other devices, the MAX5071A/MAX5071B MAX5070AASA -40C to +125C 8 SO with the highest frequency synchronizes the other devices. Alternatively, the MAX5071A/MAX5071B can MAX5070AAUA -40C to +125C 8 MAX be synchronized to an external clock with an open- MAX5070BASA -40C to +125C 8 SO drain output stage running at a higher frequency. MAX5070BAUA -40C to +125C 8 MAX The MAX5071C provides a clock output pulse Specify lead-free by adding the + symbol at the end of the part (ADV CLK) that leads the driver output (OUT) by number when ordering. 110ns. The advanced clock signal is used to drive the Ordering Information continued at end of data sheet. secondary-side synchronous rectifiers. Selector Guide appears at end of data sheet. The MAX5070/MAX5071 are available in 8-pin MAX and SO packages and operate over the automotive tem- Pin Configurations perature range of -40C to +125C. Applications TOP VIEW Universal Input AC/DC Power Supplies Isolated Telecom Power Supplies COMP 1 8 VREF Isolated Power-Supply Modules FB 2 7 V CC Networking Systems MAX5070A MAX5070B CS 3 6 OUT Computer Systems/Servers Industrial Power Conversion R /C 4 5 GND T T Isolated Keep-Alive Circuits MAX/SO MAX is a registered trademark of Maxim Integrated Products, Inc. Pin Configurations continued at end of data sheet. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com.High-Performance, Single-Ended, Current-Mode PWM Controllers ABSOLUTE MAXIMUM RATINGS V (Low-Impedance Source) to GND..................-0.3V to +30V Continuous Power Dissipation (T = +70C) CC A V (I < 30mA).....................................................Self Limiting 8-Pin MAX (derate 4.5mW/C above +70C) .............362mW CC CC OUT to GND ...............................................-0.3V to (V + 0.3V) 8-Pin SO (derate 5.9mW/C above +70C)...............470.6mW CC OUT Current.............................................................1A for 10s Operating Temperature Range (Automotive) ....-40C to +125C FB, SYNC, COMP, CS, R /C , VREF to GND...........-0.3V to +6V Maximum Junction Temperature .....................................+150C T T COMP Sink Current (MAX5070)..........................................10mA 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 = +15V, R = 10k, C = 3.3nF, V = OPEN, C = 0.1F, COMP = OPEN, V = 2V, CS = GND, T = -40C to +85C, CC T T VREF VREF FB A unless otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS REFERENCE Output Voltage V T = +25C, I = 1mA 4.950 5.000 5.050 V VREF A VREF Line Regulation V 12V < V < 25V, I = 1mA 0.4 4 mV LINE CC VREF Load Regulation V 1mA < I < 20mA 6 25 mV LOAD VREF Total Output Variation V 1mA < I < 20mA, 12V < V < 25V 4.9 5.1 V REFT VREF CC Reference Output-Noise Voltage V 10Hz < f < 10kHz, T = +25C 50 V NOISE A Reference Output Short Circuit I V = 0V -30 -100 -180 mA S SC VREF OSCILLATOR Initial Accuracy T = +25C 51 54 57 kHz A Voltage Stability 12V < V < 25V 0.2 0.5 % CC Temp Stability -40C < T < +85C 0.5 % A R /C Voltage Ramp ()V 1.7 V T T P-P RAMP R /C Voltage Ramp Valley V 1.1 V T T RAMP VALLEY Discharge Current I V = 2V, T = +25C 7.9 8.3 8.7 mA DIS RT/CT A Frequency Range f 20 1000 kHz OSC ERROR AMPLIFIER (MAX5070A/MAX5070B) FB Input Voltage V FB shorted to COMP 2.465 2.5 2.535 V FB FB Input Bias Current I -0.01 -0.1 A B(FB) Open-Loop Voltage Gain A 2V V 4V 100 dB VOL COMP Unity-Gain Bandwidth f 1 MHz GBW Power-Supply Rejection Ratio PSRR 12V V 25V (Note 2) 60 80 dB CC COMP Sink Current I V = 2.7V, V = 1.1V 2 6 mA SINK FB COMP COMP Source Current I V = 2.3V, V = 5V -0.5 -1.2 -1.8 mA SOURCE FB COMP COMP Output High Voltage V V = 2.3V, R = 15k to GND 5 5.8 V COMPH FB COMP COMP Output Low Voltage V V = 2.7V, R = 15k to VREF 0.1 0.5 V COMPL FB COMP CURRENT-SENSE AMPLIFIER Gain A (Notes 3, 4) 2.85 3 3.26 V/V CS MAX5070A/B (Note 3) 0.95 1 1.05 Maximum Current-Sense Signal V V CS MAX V = 5V, MAX5071 0.95 1 1.05 COMP 2 MAX5070/MAX5071