MAX5068 19-3176 Rev 1 7/04 High-Frequency, Current-Mode PWM Controller with Accurate Programmable Oscillator General Description Features Current-Mode Control with 47A (typ) Startup The MAX5068 is a high-frequency, current-mode, Current pulse-width modulation (PWM) controller that integrates all the building blocks necessary for implementing AC- Resistor-Programmable 4.5% Accurate DC or DC-DC fixed-frequency power supplies. Isolated Switching Frequency: 25kHz to 1.25MHz (MAX5068A/B) or nonisolated power supplies are easily constructed 12.5kHz to 625kHz (MAX5068C/D/E/F) using either primary- or secondary-side regulation. Current-mode control with leading-edge blanking sim- Rectified 85V to 265V or 36V to 72V AC AC DC DC plifies control-loop design, and a programmable inter- Input (MAX5068A/C/D) nal slope-compensation circuit stabilizes the current Input Directly Driven from 10.8V to 24V loop when operating at duty cycles above 50%. The (MAX5068B/E/F) MAX5068A/B limit the maximum duty cycle to 50% for Frequency Synchronization Input use in single-ended forward converters. The (MAX5068A/B/C/E) MAX5068C/D/E/F allow duty cycles up to 75%. The Programmable Dead Time and Slope MAX5068 features an accurate externally programma- Compensation ble oscillator that simplifies system design. Programmable Startup Voltage (UVLO) An input undervoltage lockout (UVLO) programs the Programmable UVLO Hysteresis input-supply startup voltage and ensures proper opera- (MAX5068A/B/D/F) tion during brownout conditions. Integrating Fault Protection (Hiccup) A single external resistor programs the output switching -40C to +125C Automotive Temperature Range frequency from 12.5kHz to 1.25MHz. The MAX5068A/ B/C/E provide a SYNC input for synchronization to an 16-Pin Thermally Enhanced TSSOP-EP Package external clock. The maximum FET-driver duty cycle is Ordering Information 50% for the MAX5068A/B and 75% for the MAX5068C/ D/E/F. Programmable hiccup current limit provides PART TEMP RANGE PIN-PACKAGE additional protection under severe faults. MAX5068AAUE -40C to +125C 16 TSSOP-EP* The MAX5068 is specified over the -40C to +125C MAX5068BAUE -40C to +125C 16 TSSOP-EP* automotive temperature range and is available in a MAX5068CAUE -40C to +125C 16 TSSOP-EP* 16-pin thermally enhanced TSSOP-EP package. Refer to the MAX5069 data sheet for dual FET-driver applications. MAX5068DAUE -40C to +125C 16 TSSOP-EP* Warning: The MAX5068 is designed to work with high MAX5068EAUE -40C to +125C 16 TSSOP-EP* voltages. Exercise caution. MAX5068FAUE -40C to +125C 16 TSSOP-EP* *EP = Exposed pad. Applications Pin Configurations Universal-Input AC Power Supplies TOP VIEW Isolated Telecom Power Supplies RT 1 16 REG5 Networking System Power Supplies SYNC 2 15 IN Server Power Supplies HYST 3 14 V CC MAX5068A/B Industrial Power Conversion 4 DT 13 NDRV UVLO/EN 5 12 AGND FB 6 11 PGND COMP 7 10 AGND FLTINT 8 9 CS TSSOP-EP Pin Configurations continued at end of data sheet. Selector Guide appears 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-Frequency, Current-Mode PWM Controller with Accurate Programmable Oscillator ABSOLUTE MAXIMUM RATINGS IN to PGND ............................................................-0.3V to +30V AGND to PGND.....................................................-0.3V to +0.3V IN to AGND.............................................................-0.3V to +30V Continuous Power Dissipation V to PGND..........................................................-0.3V to +13V 16-Pin TSSOP-EP (derate 21.3mW/C above +70C)...1702mW CC V to AGND..........................................................-0.3V to +13V Operating Temperature Range..........................-40C to +125C CC FB, COMP, CS, HYST, SYNC, REG5 to AGND ........-0.3V to +6V Maximum Junction Temperature .....................................+150C UVLO/EN, RT, DT, SCOMP, FLTINT to AGND .........-0.3V to +6V Storage Temperature Range .............................-60C to +150C NDRV to PGND...........................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C CC 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 = +12V for the MAX5068B/E/F V = +23.6V for the MAX5068A/C/D at startup, then reduces to +12V C = C = 0.1F IN IN IN REG5 C = 1F R = 100k NDRV = floating T = T to T , unless otherwise noted. Typical values are at T = +25C.) (Note 1) VCC RT A MIN MAX A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS UNDERVOLTAGE LOCKOUT/STARTUP Bootstrap UVLO Wake-Up Level V V rising, MAX5068A/C/D only 19.68 21.6 23.60 V SUVR IN Bootstrap UVLO Shutdown Level V V falling, MAX5068A/C/D only 9.05 9.74 10.43 V SUVF IN UVLO/EN Wake-Up Threshold V V rising 1.205 1.230 1.255 V ULR2 UVLO/EN UVLO/EN Shutdown Threshold V V falling 1.18 V ULF2 UVLO/EN MAX5068A/B/D/F only, sinking 50mA, HYST FET On-Resistance R 10 D S ( ON) H V = 0V UVLO/EN HYST FET Leakage Current I V = 2V, V = 5V 3 nA LEAK H UVLO/EN HYST IN Supply Current In I V = +19V, V < V 47 90 A START IN UVLO/EN ULF2 Undervoltage Lockout IN Range V 10.8 24.0 V IN INTERNAL SUPPLIES (V and REG5) CC V Regulator Set Point V V = + 10.8V to +24 V, V sourci ng 1A to 25mA 7.0 10.5 V CC CCSP IN C C REG5 Output Voltage V I = 0 to 1mA 4.85 5.00 5.15 V REG5 REG5 REG5 Short-Circuit Current Limit I 18 mA REG5 SC f = 1.25MHz 5 SW IN Supply Current After Startup I V = +24V mA IN IN f = 100kHz 2.5 SW Shutdown Supply Current I 90 A IN SD GATE DRIVER (NDRV) Z NDRV sinking 100mA 2 4 OUT(LOW) Driver Output Impedance Z NDRV sourcing 25mA 3 6 OUT(HIGH) Sinking 1000 Driver Peak Output Current I mA NDRV Sourcing 650 PWM COMPARATOR Comparator Offset Voltage V V - V 1.30 1.60 2.00 V OS PWM COMP CS Comparator Propagation Delay t V = 0.1V 40 ns PD PWM CS Minimum On-Time t Includes t 110 ns ON(MIN) CS BLANK CURRENT-LIMIT COMPARATOR Current-Limit Trip Threshold V 298 314 330 mV CS 2 MAX5068