MAX8540, MAX8541 Synchronizable, High-Frequency Current- And Voltage-Mode PWM Controllers For Isolated Supplies

The MAX8540 MAX8541 pulse-width-modulated (PWM) controllers for forward/flyback isolated DC-to-DC converters provide maximum flexibility to power-supply designers and reduce external component count. These controllers allow common PC board layout for current-mode MAX8540 and voltage-mode MAX8541 designs.
Both controllers feature adjustable switching frequency and external synchronization from 200kHz to 1MHz. Active-high and active-low enable, undervoltage protection (UVP), and overvoltage protection (OVP) reduce external component count.
Maximum duty cycle is adjustable, and the feed-forward function scales the maximum duty cycle with input voltage to limit the maximum volt-seconds applied to the transformer primary. The MAX8540 allows the user to select the value of slope compensation to further optimize magnetics design. The MAX8541 features user-adjustable ramp magnitude for the PWM Comparator
A cycle-by-cycle current-limit function controls the peak primary current during overload and short circuit. Both controllers CAN be set to latch off or to hiccup when a short circuit is detected. The number of current-limited cycles to initiate the hiccup mode and number of cycles skipped are user selectable to allow startup with high-capacitance loads and protect the converter against sustained short circuits.
The MAX8540 MAX8541 feature 9 internal Gate drivers for low-power applications and are compatible with external Gate drivers for high-power applications. Both devices are available in the space-saving 16-pin QSOP package.
The MAX8541 EV kit evaluates the MAX8540 and the MAX8541 to speed designs. Design examples are also available in application notes: 50W Voltage-Mode Forward Converter Design with the MAX8541 and 50W Current-Mode Forward Converter Design with the MAX8540.
By Maxim Integrated Products