MAXREFDES1040: 59.4W, No-Opto Flyback DC-DC Converter Using MAX17690


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The MAX17690 is a peak current mode, fixed-frequency switching controller specifically designed for the isolated flyback topology operating in Discontinuous Conduction Mode (DCM). The device senses the isolated output voltage directly from the primary-side flyback waveform during the off-time of the primary switch. No auxiliary winding or optocoupler is required for output voltage regulation.

The MAX17690 is designed to operate over a wide supply range from 4.5V to 60V. The switching frequency is programmable from 50kHz to 250kHz. The MAX17690 provides an input overvoltage protection through the OVI pin. The 7V internal LDO output of the MAX17690 makes it suitable for switching both logic-level and standard MOSFETs used in flyback converters. With 2A/4A source/ sink currents, the MAX17690 is ideal for driving low RDS(ON) power MOSFETs with fast gate transition times. The MAX17690 provides an adjustable soft-start feature to limit the inrush current during startup.

The MAX17690 provides temperature compensation for the output diode forward-voltage drop. The MAX17690 has robust hiccup-protection and thermal protection schemes, and is available in a space-saving 3mm x 3mm 16-pin TQFN package with a temperature range from -40°C to +125°C.


  • No Optocoupler or Third Winding Required
  • 2A/4A Peak Source/Sink Gate Drive Currents
  • 50kHz to 250kHz Programmable Switching Frequency
  • Input EN/UVLO Feature
  • Input Overvoltage Protection
  • Programmable Soft-Start
  • Hiccup-Mode Short-Circuit Protection
  • Thermal Shutdown Protection
  • -40°C to +125°C Operating Temperature Range
  • Space-Saving, 3mm x 3mm, 16-Pin TQFN Package


Designed, Built, Tested

Board pictured here has been fully assembled and tested. Not available for sale.



Input Type Vin(Min) Vin(Max) Iout(Max) Single/Multiple Output Vout(V) Pout(W) Isolated/Non-Isolated Topology
DC 18 60 1.1 - 54 59.4 Isolated Flyback


Input Type DC
Vin(Min) 18
Vin(Max) 60
Iout(Max) 1.1
Single/Multiple Output -
Vout(V) 54
Pout(W) 59.4
Isolated/Non-Isolated Isolated
Topology Flyback

Maxim Devices (1)

Part Number Name Product Family Order Design kits and evaluation modules
MAX17690 60V, No-Opto Isolated Flyback Controller Isolated Power Buy Now Design Kits

Maxim Devices (1)

Part Number Product Family
Isolated Power
60V, No-Opto Isolated Flyback Controller

Design Files (4)

Title Type Size Date
maxrefdes1040-pcb PDF 2MB 2019-07-09
maxrefdes1040-schematic PDF 21KB 2019-07-09
TTS MAXREFDES Test Results Template_Rev 0_0318 PDF 196KB 2019-07-09
maxrefdes1040-bom PDF 216KB 2019-07-09
Date Type


(PDF, 2MB)



(PDF, 21KB)


TTS MAXREFDES Test Results Template_Rev 0_0318

(PDF, 196KB)



(PDF, 216KB)

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