EVALUATION KIT AVAILABLE Click here for production status of specific part numbers. MAX17498A/ AC-DC and DC-DC Peak Current-Mode Converters MAX17498B/ for Flyback/Boost Applications MAX17498C General Description Benefits and Features The MAX17498A/MAX17498B/MAX17498C devices are Peak Current-Mode Converter current-mode fixed-frequency flyback/boost converters Current-Mode Control Provides Excellent Transient with a minimum number of external components. They Response contain all the control circuitry required to design wide 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/ Flexible Error Amplifier to Regulate Both Positive and MAX17498C support UVLO thresholds suitable to low- Negative Outputs voltage DC-DC applications. Programmable Voltage or Current Soft-Start The switching frequency of the MAX17498A/MAX17498C Power-Good Signal (PGOOD) is 250kHz, while that of the MAX17498B is 500kHz. These frequencies allow the use of tiny magnetic and filter com- Reduced Power Dissipation Under Fault ponents, resulting in compact, cost-effective power sup- Overcurrent Protection plies. An EN/UVLO input allows the user to start the power Thermal Shutdown with Hysteresis supply precisely at the desired input voltage, while also Robust Protection Features functioning as an on/off pin. The OVI pin enables imple- Programmable Current Limit mentation of an input overvoltage-protection scheme that Input Overvoltage Protection ensures that the converter shuts down when the DC input voltage exceeds the desired maximum value. Optimized Loop Performance The devices incorporate a flexible error amplifier and Fixed Default Slope Compensation in Current an accurate reference voltage (REF) to enable the end Soft-Start user to regulate both positive and negative outputs. Fixed Default and Programmable Slope Compen- Programmable current limit allows proper sizing and pro- sation in Voltage Soft-Start tection of the primary switching FET. The devices support High Efficiency a maximum duty cycle greater than 92% and provide Low R , 175m, 65V Rated Internal n-Chan- DSON programmable slope compensation to allow optimization nel MOSFET of control loop performance. The devices provide an No Current-Sense Resistor open-drain PGOOD pin that serves as a power-good Optional Spread Spectrum indicator and enters the high-impedance state to indi- Space-Saving, 16-Pin (3mm x 3mm) TQFN Package cate that the flyback/boost converter is in regulation. An SS pin allows programmable soft-start time for the Applications flyback/boost converter. Hiccup-mode overcurrent pro- tection and thermal shutdown are provided to minimize Front-End AC-DC Power Supplies for Industrial dissipation under overcurrent and overtemperature fault Applications (Isolated and Nonisolated) conditions. The devices are available in a space-saving, Telecom Power Supplies 16-pin (3mm x 3mm) TQFN package with 0.5mm lead Wide Input Range DC Input Flyback/Boost Industrial spacing. Power Supplies Ordering Information and Typical Application Circuits appear at end of data sheet. 19-6043 Rev 4 10/20MAX17498A/ AC-DC and DC-DC Peak Current-Mode Converters for MAX17498B/ Flyback/Boost Applications MAX17498C 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 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. Package Information PACKAGE TYPE: 16 TQFN Package Code T1633+5 Outline Number 21-0136 Land Pattern Number 90-0032 For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a +, , or - in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. 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 (V ) IN MAX17498A 4.5 29 IN Voltage Range (V ) V IN MAX17498B/MAX17498C 4.5 36 IN Supply Startup Current Under I , V < UVLO or EN/UVLO = SGND 22 36 A INSTARTUP IN UVLO Switching, f = 250kHz (MAX17498A/MAX17498C) 1.8 3 SW IN Supply Current (I ) mA IN Switching, f = 500kHz (MAX17498B) 2 3.25 SW 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, I = 1mA (MAX17498A) (Note 2) 31 33.5 36 V IN Maxim Integrated 2 www.maximintegrated.com