LT3761 without PWM

Dear Sir, please answer

I'd like to use LT3761  without dimming. I need 16 LEDs with 3 V voltage drop at 1A current, then total voltage 16x3=48V.

I have 10-30V power supply. I use LTSpice circuit with  LT3761 , please, see attachs.


1) Can I remove M2 transistor and connect cathode of the LED to GND? I "removed" M2, but R4 the current is still "pulsed".  Because the M1 transistor is also controlled by pulses with the same frequency as M2. Only, there is a high-frequency "filling"  in M1. Why then do we need M2?

2) Diode D4 (LED) marked as "N=17". Is it mean that 17 LEDs installed in series? But how are these 17 LEDs obtained? On the diagram, after all, single LED. If I understand right, it indicated somewhere in the "program code" of these "17  LEDs" ?  How can I set "N=1" i.e a single LED ?

3) C2 parameters indicate 2.2 microfarads, but C2 marked as "2.2 x 4". And what is the real value?

4)  Can I remove V2 power supply? It used for simulation only?

5) Please, see did I draw correctly the circuit without dimming ?

initial circuit:


waveform for circuit without M2 transistor:

The circuit  without M2  transistor:

Circuit without dimming:



Vladimir Naumenkov

LT3761_TA02A_DC1772A (1).asc

LT3761_without M2-.asc

LT3761_without dimming.asc

I edited questions
[edited by: naumenkov123 at 6:03 PM (GMT 0) on 28 Apr 2020]
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