Ω pullup resistor to

enable the latch-off feature. In this mode, once the

SKTON time has elapsed, the IC is latched off. The cir-

cuit remains off until EN is toggled, or the input power is

toggled.

Soft-Start Capacitor Selection

During startup, the capacitor at soft-start is charged

using a 5µA current source. Once the voltage at soft-

start reaches the threshold voltage (2V typ), the IC

switches normally. Use a low-ESR ceramic capacitor

placed as close as possible to the IC at soft-start. The

value is determined as follows:

is in µF.

Applications Information

Refer to the following application notes for the

MAX8540/MAX8541 application circuits and applica-

tions information: 50W Current-Mode Forward

Converter Design with the MAX8540 and 50W Voltage-

Mode Forward Converter Design with the MAX8541.

C

t

SS

SS

=

530

Synchronizable, High-Frequency Current- and

Voltage-Mode PWM Controllers for Isolated Supplies

12

______________________________________________________________________________________

TOP VIEW

16

15

14

13

12

11

10

9

1

2

3

4

5

6

7

8

REF

DRV

GND

SKTON

CS

SKTOFF

ILIM

OPTO

MAX8541EEE

QSOP

OV

UV

MAXDTY

FREQ/SYNC

SS

EN

PRAMP

Pin Configurations (continued)

Chip Information

TRANSISTOR COUNT: 2704

PROCESS: BiCMOS