LT8301 datasheet(18/24 Pages) AD

Part #	LT8301

Description	42VIN Micropower No-Opto Isolated Flyback Converter with 65V/1.2A Switch

PDF	24 Pages

Scroll/Zoom	100%

Manufacturer	AD [Analog Devices]

Direct Link	http://www.analog.com

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18 / 24 page

LT8301

Rev. B

For more information www.analog.com

APPLICATIONS INFORMATION

Step 7: Select the EN/UVLO Resistors.

Determine the amount of hysteresis required and calcu-

late R1 resistor value:

VIN(HYS) = 2.5µA • R1

Example:

Choose 2V of hysteresis,

R1 = 806k

Determine the UVLO thresholds and calculate R2 resistor

value:

VIN(UVLO+) =

1.242V •(R1

+R2)

+2.5µA •R1

Example:

Set VIN UVLO rising threshold to 7.5V,

R2 = 232k

VIN(UVLO+) = 7.5V

VIN(UVLO–) = 5.5V

Step 8: Ensure minimum load.

The theoretical minimum load can be approximately esti-

mated as:

ILOAD(MIN) =

40µH•(360mA)2 •10.6kHz

2•5V

= 5.5mA

Remember to check the minimum load requirement in

real application. The minimum load occurs at the point

where the output voltage begins to climb up as the con-

verter delivers more energy than what is consumed at

the output. The real minimum load for this application is

about 6mA. In this example, a 820Ω resistor is selected

as the minimum load.

LT8301 Datasheet(PDF) 18 Page - Analog Devices