MAX17550
21Pages

60V, 25mA, Ultra-Small, High-Efficiency, Synchronous Step-Down DC-DC Converter with 22µA No-Load Supply Current General Description The MAX17550 uses peak-current-mode control. The device can be operated in pulse-width modulation (PWM) or pulse-frequency modulation (PFM) modes. ●● Reduces Number of DC-DC Regulators to Stock • Wide 4V to 60V Input • Adjustable 0.8V to 0.9 x VIN Output • 100kHz to 2.2MHz Adjustable Switching Frequency with External Synchronization The MAX17550 high-efficiency, high-voltage, synchronous step-down DC-DC converter with integrated MOSFETs operates over a 4V to 60V input. The converter can deliver up to 25mA and generates output voltages from 0.8V up to 0.9 x VIN. The feedback (FB) voltage is accurate to within ±1.75% over -40°C to +125°C. ●● Reduces External Components and Total Cost • No Schottky–Synchronous • Internal Compensation for Any Output Voltage • Built-In Soft-Start • All-Ceramic Capacitors, Compact Layout The device is available in a 10-pin (3mm x 2mm) TDFN and 10-pin (3mm x 3mm) μMAX® packages. Simulation models are available. ●● Reduces Power Dissipation • 22µA Quiescent Current • Peak Efficiency > 90% • PFM Enables Enhanced Light-Load Efficiency • 1.2µA Shutdown Current Industrial sensors and Process control High-Voltage LDO Replacement Battery-Powered Equipment HVAC and Building Control ●● Operates Reliable in Adverse Environments • Peak Current-Limit Protection • Built-In Output-Voltage Monitoring RESET • Programmable EN/UVLO Threshold • Monotonic Startup Into Prebiased Load • Overtemperature Protection • High Industrial -40°C to +125°C Ambient Operating Temperature Range / -40°C to +150°C Junction Temperature Range Ordering Information appears at end of data sheet. µMAX is a registered trademark of Maxim Integrated Products, Inc. Typical Application Circuits—High-Efficiency 5V, 25mA Regulator VIN 6V TO 60V CIN 1µF SS VOUT MODE FB RT/SYNC R3 191kΩ SWITCHING FREQUENCY = 220kHz L1 COILCRAFT LPS5030-105M CO

60V, 25mA, Ultra-Small, High-Efficiency Synchronous Step-Down DC-DC Converter with 22^A No-Load Supply CurrentAbsolute Maximum Ratings (Note 1) Continuous Power Dissipation (Ta = +70°C) 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. Note 1: Junction...

60V, 25mA, Ultra-Small, High-Efficiency Synchronous Step-Down DC-DC Converter with 22^A No-Load Supply Current Electrical Characteristics (V|N = 24V, VGND = 0V, VOUT = 3.3V, VFB = 0.85V, Ven/UVlo = 1.5V, RT/SYNC = 191kD, LX = SS = MODE = RESET = unconnected; Ta = -40°C to +125°C, unless otherwise noted. Typical values are at Ta = +25°C. All voltages are referenced to GND, unless otherwise noted.) (Note 2)

60V, 25mA, Ultra-Small, High-Efficiency Synchronous Step-Down DC-DC Converter with 22^A No-Load Supply Current Electrical Characteristics (continued) (V|N = 24V, VGND = 0V, Vqut = 3.3V, VFB = 0.85V, Ven/UVlo = 1.5V, RT/SYNC = 191kD, LX = SS = MODE = RESET = unconnected; Ta = -40°C to +125°C, unless otherwise noted. Typical values are at Ta = +25°C. All voltages are referenced to GND, unless otherwise noted.) (Note 2)

60V, 25mA, Ultra-Small, High-Efficiency Synchronous Step-Down DC-DC Converter with 22^A No-Load Supply Current Electrical Characteristics (continued) (V|N = 24V, VGND = 0V, Vqut = 3.3V, VFB = 0.85V, Ven/UVlo = 1.5V, RT/SYNC = 191kD, LX = SS = MODE = RESET = unconnected; Ta = -40°C to +125°C, unless otherwise noted. Typical values are at Ta = +25°C. All voltages are referenced to GND, unless otherwise noted.) (Note 2) Note 2: Limits are 100% tested at Ta = +25°C. Limits over the operating temperature range and relevant supply voltage range are guaranteed by design and characterization. Note...

60V, 25mA, Ultra-Small, High-Efficiency Synchronous Step-Down DC-DC Converter with 22µA No-Load Supply Current Typical Operating Characteristics (VIN = 24V, VGND = 0V, VOUT = 3.3V, VEN/UVLO = 1.5V, RT/SYNC = 191kΩ, CIN = 1μF, TA = +25°C unless otherwise noted) EFFICIENCY vs. LOAD CURRENT EFFICIENCY vs. LOAD CURRENT FIGURE 6 APPLICATION CIRCUIT, PWM MODE, VOUT = 5V, FSW = 220kHz (RRT=191k) EFFICIENCY vs. LOAD CURRENT EFFICIENCY vs. LOAD CURRENT FIGURE 9 APPLICATION CIRCUIT, PFM MODE, VOUT = 3.3V FSW = 600kHz (RRT = 69.8k) 1 VIN = 24V FIGURE 9 APPLICATION CIRCUIT, PWM MODE, VIN = 12V VOUT =...

Synchronous Step-Down DC-DC Converter with 22^A No-Load Supply Current Typical Operating Characteristics (continued) (Vin = 24V, Vgnd = 0V, Vqut = 3.3V, Ven/uvlo = 1.5V, RT/SYNC = 191kO, C|n = 1pF, Ta = +25°C unless otherwise noted) OUTPUT VOLTAGE vs. LOAD CURRENT OUTPUT VOLTAGE vs. LOAD CURRENT toc12 OUTPUT VOLTAGE OUTPUT VOLTAGE vs LOAD CURRENT OUTPUT VOLTAGE

Synchronous Step-Down DC-DC Converter with 22^A No-Load Supply Current Typical Operating Characteristics (continued) (V|n = 24V, Vgnd = 0V, Vqut = 3.3V, Ven/uvlo = 1.5V, RT/SYNC = 191kQ, C|n = 1mF, Ta = +25°C unless otherwise noted) RESETTHRESHOLD (%) SWITCH CURRENT LIMIT (A) SHUTDOWN CURRENT (|jA) SWITCH CURRENT LIMIT VS. TEMPERATURE EN/UVLO THRESHOLD VOLTAGE VS. TEMPERATURE SWITCHING FREQUENCY VS. TEMPERATURE LOAD TRANSIENT RESPONSE PFM MODE (LOAD CURRENT STEPPED FROM 5mA to17.5mA)

60V, 25mA, Ultra-Small, High-Efficiency Synchronous Step-Down DC-DC Converter with 22µA No-Load Supply Current Typical Operating Characteristics (continued) (VIN = 24V, VGND = 0V, VOUT = 3.3V, VEN/UVLO = 1.5V, RT/SYNC = 191kΩ, CIN = 1μF, TA = +25°C unless otherwise noted) LOAD TRANSIENT RESPONSE PFM OR PWM MODE (LOAD CURRENT STEPPED FROM 12.5mA TO 25mA) LOAD TRANSIENT RESPONSE PFM OR PWM MODE (LOAD CURRENT STEPPED FROM 12.5mA TO 25mA) 10mA/div FIGURE 7 APPLICATION CIRCUIT VOUT = 3.3V FIGURE 6 APPLICATION CIRCUIT VOUT = 5V FIGURE 6 APPLICATION CIRCUIT VOUT = 5V LOAD TRANSIENT RESPONSE PWM...