General DescriptionThe MAX17497A/MAX17497B include both a current mode fixed-frequency flyback converter and a synchronous step-down regulator. They contain all the control circuitry required to design wide input-voltage nonisolated power supplies to supply multiple output rails for smart meters, industrial control, and other similar applications. The MAX17497A has its rising/falling undervoltage lockout (UVLO) thresholds optimized for universal offline (85V AC to 265V AC) applications, while the MAX17497B supports undervoltage lockout (UVLO) thresholds suitable to low-voltage DC-DC applications. Both devices also include a 3.3V fixed-output synchronous step-down regulator that delivers up to 600mA load current.

Benefits and Features♦ Reduced Component Count and Board Space
◇ Flyback/Boost with Integrated Internally
Compensated Step-Down Regulator
◇ No Current-Sense Resistor
◇ Space-Saving 16-Pin (3mm x 3mm) TQFN
Package
♦ Minimal Radio Interference
◇ 250kHz Switching in Offline Version
Minimizes Interference with Radio Receivers
in Smart Meter Applications
♦ Reduced Inrush Current
◇ Programmable Flyback/Boost Soft-Start
◇ Internal Digital Soft-Start for Step-Down
Regulator
♦ Reduced Power Dissipation Under Fault
◇ Hiccup Mode Overcurrent Protection
◇ Thermal Shutdown with Hysteresis
♦ Robust Protection Features
◇ Flyback/Boost Programmable Current Limit
◇ Input Overvoltage Protection
♦ Optimized Loop Performance
◇ Programmable Slope Compensation for
Flyback/Boost Maximizes Obtainable Phase
Margin
♦ High Efficiency
◇ Low RDSON, 150mI, 65V-Rated Internal
nMOSFET
◇ 3.3V Step-Down Regulator Efficiency Greater
Than 90%
♦ Optional Spread Spectrum

Applications AC-DC Power Supplies for Smart Meter Applications
Universal-Input Offline AC-DC Power Supplies
Wide-Range DC Input Flyback/Boost Industrial Power Supplies

Manufacturer	Maxim Integrated
Product Category	AC DC Converters, Offline Switchers
Series	MAX17497A
Type	Fixed Frequency Flyback Converter
Packaging	Alternate Packaging
Mounting-Style	SMD/SMT
Operating-Temperature-Range	- 40 C to + 125 C
Package-Case	16-WFQFN Exposed Pad
Operating-Temperature	-40°C ~ 125°C (TJ)
Mounting-Type	Surface Mount
Supplier-Device-Package	16-TQFN (3x3)
Watt	-
Number-of-Outputs	2 Output
Output-Isolation	Isolated
Internal-Switch-s	No
Voltage-Breakdown	-
Topology	Flyback
Voltage-Start-Up	-
Voltage-Supply-Vcc-Vdd	4.5 V ~ 29 V
Duty-Cycle	94.50%
Frequency-Switching	250kHz
Fault-Protection	Current Limiting, Over Voltage
Control-Features	EN, Soft Start
Isolation	Isolated
Maximum Operating Temperature	+ 125 C
Output-Voltage	3.3 V 5 V
Operating-Supply-Current	2.75 mA
Output-Current	600 mA
Switching-Frequency	250 kHz
Part-#-Aliases	MAX17497A
Package-Case	TQFN-16
Duty-Cycle-Max	97 %
Input-Supply-Voltage-Min	4.5 V
Input-Supply-Voltage-Max	29 V