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LM3404 constant current LED driver component calculator

Add a 1kOhm resistor between CS pin and Rsns for input pin protection, at least during development.

Pull Ron to ground for low-power shutdown (with small FET such as 2N7000).

Input and output capacitors should be multilayer ceramic, at least X5R, but X7R preferred.

Design parameters
Input voltage V
Input voltage regulation (+-) %
LED forward voltage V
LED current A
LED current ripple A
Switching frequency kHz
Results
Ron kOhms
ton ns
L1 minimum inductance
(choose next common size up)
uH
L1 max current ripple mA
L1 peak current mA
Output capacitor Co capacitance uF
Rsns resistance Ohms
Input capacitor Cin capacitance
(Use 2x the value)
uF
D1 average current
(Use 2A Schottky diode for best efficiency)
mA
D1 average power dissipation mW
Bootstrap capacitor Cb nF
VCC capacitor Cf nF

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