The MAX5019/MAX5020 integrate all the building blocks necessary for implementing DC-DC fixed-frequency power supplies. Either primary- or secondaryside regulation may be used to implement isolated or nonisolated power supplies. These devices are currentmode controllers with an integrated high-voltage startup circuit suitable for telecom/industrial voltage range power supplies. Current-mode control with leadingedge blanking simplifies control-loop design and internal ramp compensation circuitry stabilizes the current loop when operating at duty cycles above 50% (MAX5019). The MAX5019 allows 85% operating duty cycle and can be used to implement flyback converters whereas the MAX5020 limits the operating duty cycle to less than 50% and can be used in single-ended forward converters. A high-voltage startup circuit allows these devices to draw power directly from the 18V to 110V input supply during startup. The switching frequency is internally trimmed to 275kHz ±10%, thus reducing magnetics and filter component costs.
The MAX5019/MAX5020 are available in 8-pin SO packages.
V+ to GND.....................-0.3V to +120V
VDD to GND..................... -0.3V to +40V
VCC to GND.................... -0.3V to +12.5V
FB, NDRV, SS_SHDN, CS to GND ....... -0.3V to VCC + 0.3V
VDD and VCC Current ....................20mA
NDRV Current Continuous....................25mA
NDRV Current for Less than 1µs.................±1A
Continuous Power Dissipation (TA = +70°C)
8-Pin SO (derate 5.88mW/°C above +70°C) ...... 471mW
Operating Temperature Range..........-40°C to +85°C
Storage Temperature Range.......... -65°C to +150°C
Lead Temperature (soldering, 10s) ............ +300°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.
Required Field 
