Texas Instruments LM3423 Evaluation Board LM3423BBLSCSEV/NOPB LM3423BBLSCSEV/NOPB Datenbogen
Produktcode
LM3423BBLSCSEV/NOPB
V
RD-MAX
= V
IN-MAX
DSON
2
RMS
T
T
R
I
P
x
=
-
I
RMS
T
=
-
D
x
I
LED
D
c
D
I
T-
I
LED
RMS
x
=
I
T-MAX
= x I
LED
1 - D
MAX
D
MAX
I
T-MAX
= D
MAX
x I
LED
O
MAX
IN
MAX
T
V
V
V
+
=
-
-
O
V
=
MAX
T
V
-
MAX
IN
MAX
T
V
V
-
-
=
1-D
MAX
D
MAX
I
CIN-RMS
= I
LED
x
12
I
CIN-RMS
=
'
i
L-PP
SNVS574E – JULY 2008 – REVISED MAY 2013
Boost
(73)
Buck-boost
(74)
9. NFET
The NFET voltage rating should be at least 15% higher than the maximum NFET drain-to-source voltage (V
T-
MAX
):
Buck
(75)
Boost
(76)
Buck-boost
(77)
The current rating should be at least 10% higher than the maximum average NFET current (I
T-MAX
):
Buck
(78)
Boost and Buck-boost
(79)
Approximate the nominal RMS transistor current (I
T-RMS
) :
Buck
(80)
Boost and Buck-boost
(81)
Given an NFET with on-resistance (R
DS-ON
), solve for the nominal power dissipation (P
T
):
(82)
10. DIODE
The Schottky diode voltage rating should be at least 15% higher than the maximum blocking voltage (V
RD-MAX
):
Buck
(83)
36
Copyright © 2008–2013, Texas Instruments Incorporated
Product Folder Links: