Texas Instruments LM3448 -120VAC, 6W Isolated Flyback LED Driver Eval Board LM3448-120VFLBK/NOPB LM3448-120VFLBK/NOPB 데이터 시트
제품 코드
LM3448-120VFLBK/NOPB
Design Calculations
14
Design Calculations
The following is a step-by-step procedure with calculations for a 120V, 6.5W flyback design.
14.1 Specifications
f
L
= 60Hz
f
SW(MIN)
=72kHz
V
IN(NOM)
= 120VAC
V
IN(MIN)
= 85VAC
V
IN(MAX)
= 135VAC
I
LED
= 245mA
Δ
v
OUT
= 1V
Δ
v
IN-PK
= 35V
SW FET V
DS(MAX)
= 600V
SW FET R
DS-ON
= 3.5
Ω
V
f(D4)
= 0.8V
V
RING
= 50V
P
OUT(MAX)
= 6.5W
V
OUT
= 26.5V
V
OVP
= 47V
V
AUX
= 13V
η
= 85%
n = 4
A
L
= 80nH/turns
2
A
e
= 19.49mm
2
V
CC
= 12V
V
Z(D6)
= 5.1V
V
BE(Q4)
= 0.7V
V
Z(D7)
=12V
R8=49.9k
Ω
V
GS(Q1)
=0.7V
14.2 Preliminary Calculations
Nominal peak input voltage:
(43)
Maximum peak input voltage:
(44)
Minimum peak input voltage:
(45)
27
SNOA554C – October 2011 – Revised May 2013
AN-2090 LM3448 -120VAC, 6W Isolated Flyback LED Driver
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