EVALUATION KIT AVAILABLE MAX17498A/MAX17498B/MAX17498C AC-DC and DC-DC Peak Current-Mode Converters for Flyback/Boost Applications General Description Benefits and Features The MAX17498A/MAX17498B/MAX17498C devices are S Peak Current-Mode Converter current-mode fixed-frequency flyback/boost converters S Current-Mode Control Provides Excellent with a minimum number of external components. They Transient Response contain all the control circuitry required to design wide S Fixed Switching Frequency input voltage isolated and nonisolated power supplies. The MAX17498A has its rising/falling undervoltage lock- 250kHz: MAX17498A/MAX17498C out (UVLO) thresholds optimized for universal offline (85V 500kHz: MAX17498B AC to 265V AC) applications, while the MAX17498B/ S Flexible Error Amplifier to Regulate Both Positive MAX17498C support UVLO thresholds suitable to low- and Negative Outputs voltage DC-DC applications. S Programmable Soft-Start to Reduce Input Inrush The switching frequency of the MAX17498A/MAX17498C Current is 250kHz, while that of the MAX17498B is 500kHz. These frequencies allow the use of tiny magnetic and filter com- S Programmable Voltage or Current Soft-Start ponents, resulting in compact, cost-effective power sup- S Power-Good Signal (PGOOD) plies. An EN/UVLO input allows the user to start the power S Reduced Power Dissipation Under Fault supply precisely at the desired input voltage, while also functioning as an on/off pin. The OVI pin enables imple- Overcurrent Protection mentation of an input overvoltage-protection scheme that Thermal Shutdown with Hysteresis ensures that the converter shuts down when the DC input S Robust Protection Features voltage exceeds the desired maximum value. Programmable Current Limit The devices incorporate a flexible error amplifier and an Input Overvoltage Protection accurate reference voltage (REF) to enable the end user to regulate both positive and negative outputs. Programmable S Optimized Loop Performance current limit allows proper sizing and protection of the primary Programmable Slope Compensation switching FET. The devices support a maximum duty cycle greater than 92% and provide programmable slope com- S High Efficiency pensation to allow optimization of control loop performance. Low R , 175mI, 65V Rated Internal DSON The devices provide an open-drain PGOOD pin that serves n-Channel MOSFET as a power-good indicator and enters the high-impedance No Current-Sense Resistor state to indicate that the flyback/boost converter is in regu- S Optional Spread Spectrum lation. An SS pin allows programmable soft-start time for the flyback/boost converter. Hiccup-mode overcurrent pro- S Space-Saving, 16-Pin (3mm x 3mm) TQFN tection and thermal shutdown are provided to minimize Package dissipation under overcurrent and overtemperature fault conditions. The devices are available in a space-saving, Applications 16-pin (3mm x 3mm) TQFN package with 0.5mm lead spacing. Front-End AC-DC Power Supplies for Industrial Applications (Isolated and Nonisolated) Ordering Information and Typical Application Circuits Telecom Power Supplies appear at end of data sheet. Wide Input Range DC Input Flyback/Boost Industrial Power Supplies For related parts and recommended products to use with this part, refer to www.maximintegrated.com/MAX17498A.related. For pricing, delivery, and ordering information, please contact Maxim Direct at 19-6043 Rev 3 4/13 1-888-629-4642, or visit Maxim Integrateds website at www.maximintegrated.com.MAX17498A/MAX17498B/MAX17498C AC-DC and DC-DC Peak Current-Mode Converters for Flyback/Boost Applications ABSOLUTE MAXIMUM RATINGS IN to SGND ............................................................-0.3V to +40V PGND to SGND ....................................................-0.3V to +0.3V EN/UVLO to SGND .........................................-0.3V to IN + 0.3V Continuous Power Dissipation (Single-Layer Board) OVI to SGND .............................................. -0.3V to V + 0.3V TQFN (derate 20.8mW/C above +70C)..................1700mW CC V to SGND ..........................................................-0.3V to +6V Operating Temperature Range ........................ -40C to +125C CC SS, LIM, EA-, EA+, COMP, SLOPE, Storage Temperature Range ............................ -65C to +160C REF to SGND ........................................-0.3V to (V + 0.3V) Junction Temperature (continuous) ................................+150C CC LX to SGND ...........................................................-0.3V to +70V Lead Temperature (soldering, 10s) ................................+300C PGOOD to SGND ....................................................-0.3V to +6V Soldering Temperature (reflow) ......................................+260C Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional opera- tion 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, V = +2V, COMP = open, C = 1F, C = 1F, T = T = -40C to +125C, unless otherwise noted. Typical IN EN/UVLO IN VCC A J values are at T = +25C.) (Note 1) A PARAMETER CONDITIONS MIN TYP MAX UNITS INPUT SUPPLY (VIN) MAX17498A 4.5 29 IN Voltage Range (VIN) V MAX17498B/MAX17498C 4.5 36 IN Supply Startup Current Under IINSTARTUP, VIN < UVLO or EN/UVLO = SGND 22 36 A UVLO Switching, fSW = 250kHz (MAX17498A/MAX17498C) 1.8 3 IN Supply Current (IIN) mA Switching, fSW = 500kHz (MAX17498B) 2 3.25 MAX17498A 19 20.5 22 IN Boostrap UVLO Rising V Threshold MAX17498B/MAX17498C 3.85 4.15 4.4 IN Bootstrap UVLO Falling 3.65 3.95 4.25 V Threshold IN Clamp Voltage EN/UVLO = SGND, IIN = 1mA (MAX17498A) (Note 2) 31 33.5 36 V LINEAR REGULATOR (VCC) VCC Output Voltage Range 6V < VIN < 29V, 0mA < IVCC < 50mA 4.8 5 5.2 V VCC Dropout Voltage VIN = 4.5V, IVCC = 20mA 160 300 mV VCC Current Limit VCC = 0V, VIN = 6V 50 100 mA ENABLE (EN/UVLO) Rising 1.18 1.23 1.28 EN/UVLO Threshold V Falling 1.11 1.17 1.21 EN/UVLO Input Leakage Current 0V < VEN/UVLO < 1.5V, TA = +25NC -100 0 +100 nA Maxim Integrated 2