MAX5052/MAX5053 19-2590 Rev 1 11/03 Current-Mode PWM Controllers with an Error Amplifier for Isolated/Nonisolated Power Supplies General Description Features The MAX5052/MAX5053 current-mode PWM controllers Available in a Tiny 8-Pin MAX Package contain all the control circuitry required for the design of Current-Mode Control wide-input-voltage isolated and nonisolated power 50W Output Power supplies. The MAX5052 is well suited for universal input (rectified 85VAC to 265VAC) or telecom (-36VDC to Universal Offline Input Voltage Range -72VDC) power supplies. The MAX5053 is well suited for Rectified 85VAC to 265VAC (MAX5052) low-input-voltage (10.8VDC to 24VDC) power supplies. V Directly Driven from 10.8V to 24V Input IN The MAX5052/MAX5053 contain an internal error ampli- (MAX5053) fier that regulates the tertiary winding output voltage. Digital Soft-Start This implements a primary-side regulated, isolated Programmable Input Startup Voltage power supply, eliminating the need for an optocoupler. An input undervoltage lockout (UVLO) is provided for Internal Bootstrap UVLO with Large Hysteresis programming the input-supply start voltage and to (MAX5052) ensure proper operation during brownout conditions. Internal Error Amplifier with 1% Accurate The input-supply start voltage is externally programma- Reference ble with a voltage-divider. To shutdown the device, the Thermal Shutdown UVLO pin is pulled low. Internal digital soft-start reduces output voltage overshoot. The internal thermal 45A (typ) Startup Supply Current shutdown circuit protects the device in the event the 1.4mA (typ) Operating Supply Current junction temperature exceeds +130C. Fixed Switching Frequency of 262kHz 12% The MAX5052 has an internal bootstrap UVLO with 50% Maximum Duty-Cycle Limit large hysteresis that requires a minimum voltage of (MAX5052A/MAX5053A) 23.6V for startup. The MAX5053 does not have the internal bootstrap UVLO and can be biased directly 75% Maximum Duty-Cycle Limit from a minimum voltage of 10.8V. (MAX5052B/MAX5053B) The 262kHz switching frequency is internally trimmed to 60ns Cycle-by-Cycle Current-Limit Response Time 12% accuracy this allows the optimization of the magnetic and filter components resulting in compact, Ordering Information cost-effective power supplies. The MAX5052A/ PART TEMP RANGE PIN-PACKAGE MAX5053A are offered with a 50% maximum duty-cycle limit. The MAX5052B/MAX5053B are offered with a 75% MAX5052AEUA -40C to +85C 8 MAX maximum duty-cycle limit. These devices are available MAX5052BEUA -40C to +85C 8 MAX in 8-pin MAX packages and operate over the -40C to MAX5053AEUA -40C to +85C 8 MAX +85C temperature range. MAX5053BEUA -40C to +85C 8 MAX Warning: The MAX5052/MAX5053 are designed to work with high voltages. Exercise caution. Applications Universal Input AC Industrial Power Pin Configuration Power Supplies Conversion Isolated Telecom Power Isolated Keep-Alive TOP VIEW Supplies Circuits Networking Systems 12V Boost Regulators UVLO/EN 1 8 V IN Computer Systems/ 12V SEPIC Regulators FB 2 7 V CC Servers MAX5052 COMP 3 6 NDRV MAX5053 CS 4 5 GND Functional Diagram/Typical Operating Circuit/Selector MAX Guide appear 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. EVALUATION KIT AVAILABLECurrent-Mode PWM Controllers with an Error Amplifier for Isolated/Nonisolated Power Supplies ABSOLUTE MAXIMUM RATINGS V to GND .............................................................-0.3V to +30V Operating Temperature Range ...........................-40C to +85C IN V to GND............................................................-0.3V to +13V Storage Temperature Range ............................-65C to +150C CC FB, COMP, UVLO, CS to GND .................................-0.3V to +6V Junction Temperature......................................................+150C NDRV to GND.............................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C CC Continuous Power Dissipation (T = +70C) A 8-Pin MAX (derate 4.5mW/C above +70C) ..............362mW 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 MAX5052, V must first be brought up to 23.6V for startup), 10nF bypass capacitors at V and V , C = 0, IN IN IN CC NDRV V = +1.4V, V = +1.0V, V = floating, V = 0V, typical values are measured at T = +25C, T = -40C to + 85C, unless UVLO FB COMP CS A A otherwise noted.) (Note 1) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS UNDERVOLTAGE LOCKOUT/STARTUP Bootstrap UVLO Wake-Up Level V V rising (MAX5052 only) 19.68 21.6 23.60 V SUVR IN Bootstrap UVLO Shutdown Level V V falling (MAX5052 only) 9.05 9.74 10.43 V SUVF IN UVLO/EN Wake-Up Threshold V UVLO/EN rising 1.188 1.28 1.371 V ULR2 UVLO/EN Shutdown Threshold V UVLO/EN falling 1.168 1.23 1.291 V ULF2 UVLO/EN Input Current I T = +125C 25 nA UVLO J UVLO/EN Hysteresis 50 mV V Supply Current In V = +19V, for MAX5052 only when in IN IN I 45 90 A START Undervoltage Lockout bootstrap UVLO V Range V 10.8 24 V IN IN t UVLO/EN steps up from +1.1V to +1.4V 12 EXTR UVLO/EN Propagation Delay s t UVLO/EN steps down from +1.4V to +1.1V 1.8 EXTF t V steps up from +9V to +24V 5 Bootstrap UVLO Propagation BUVR IN s Delay t V steps down from +24V to +9V 1 BUVF IN INTERNAL SUPPLY V = +10.8V to +24V, sinking 1A to 20mA IN V Regulator Set Point V 7 10.5 V CC CCSP from V CC V Supply Current After Startup I V = +24V 1.4 2.5 mA IN IN IN Shutdown Supply Current UVLO/EN = low 90 A GATE DRIVER R Measured at NDRV sinking, 100mA 2 4 ON(LOW) Driver Output Impedance R Measured at NDRV sourcing, 20mA 4 12 ON(HIGH) Driver Peak Sink Current 1A Driver Peak Source Current 0.65 A PWM COMPARATOR Comparator Offset Voltage VO V - V 1.15 1.38 1.70 V PWM COMP CS CS Input Bias Current I V = 0V -2 +2 A CS CS Comparator Propagation Delay t V = +0.1V 60 ns PWM CS Minimum On-Time t 150 ns ON(MIN) 2 MAX5052/MAX5053