below 0.25V to disable the controller.

Undervoltage lockout shuts down the controller when

erence remain on during shutdown.

Current-Sense Comparator

The current-sense (CS) comparator and its associated

logic limit the peak current through the MOSFET.

Current is sensed at CS as a voltage across a sense

resistor between the source of the MOSFET and GND.

To reduce switching noise, connect CS to the external

MOSFET source through a 100

Ω resistor or an RC low-

_______________________________________________________________________________________

9

Current-Mode PWM Controllers with Integrated

Startup Circuit

NDRV

100

Ω

M1

CS

GND

FB

V+

MAX5019

MAX5020

SS_SHDN

Figure 3. Nonisolated Flyback Converter

NDRV

100

Ω

M1

FB

CS

GND

V+

MAX5019

MAX5020

SS_SHDN

Figure 4. Isolated Flyback Converter