RC5041
PRODUCT SPECIFICATION
Design Considerations and
Component Selection
MOSFET Selection
This application requires N-channel Logic Level Enhance-
ment Mode Field Effect Transistors. Desired characteristics
are as follows:
• Low Static Drain-Source On-Resistance,
R
DS(on)
< 20 mΩ (lower is better)
•
•
•
•
Low gate drive voltage, V
GS
< 4V
Power package with low thermal resistance
Drain current rating of 20A minimum
Drain-Source voltage > 15V.
The on-resistance (R
DS(ON)
) is the primary parameter for
MOSFET selection. The on-resistance determines the power
dissipation of the MOSFET and therefore significantly
affects the efficiency of the DC-DC Converter. Table 3
provides a list of suitable MOSFETs for this application.
Table 3. MOSFET Selection Table
Preliminary Information
R
DS,ON
(mΩ)
Manufacturer & Model #
Megamos
MiP30N03A
Fuji
2SK1388
Int. Rectifier
IRL3803
Int. Rectifier
IRL2203
Int. Rectifier
IRL3103
NS
NDP706A
NEC
2SK2941
NEC
2SK2984
NEC
µPA1703
Int. Rectifier
IRF7413A
Int. Rectifier
IRF7413
Int. Rectifier
IRL3103A
Conditions
1
V
GS
= 4.5V,
I
D
= 6A
V
GS
= 4V,
I
D
= 20A
V
GS
= 4.5V,
I
D
= 59A
V
GS
= 4.5V,
I
D
= 50A
V
GS
= 4.5V,
I
D
= 28A
V
GS
= 5.0V,
I
D
= 40A
V
GS
= 4.0V,
I
D
= 18A
V
GS
= 4.0V,
I
D
= 20A
V
GS
= 4.0V,
I
D
= 5A
V
GS
= 4.5V,
I
D
= 3.3A
V
GS
= 4.5V,
I
D
= 3.7A
V
GS
= 4.5V,
I
D
= 28A
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
T
J
= 25°C
T
J
= 125°C
8.2
—
16
—
13
20
22
—
10.5
—
12
—
—
—
—
—
—
—
Typ.
16
—
25
37
6.1
Max.
25
38
37
56
9
14
10
16
19
29
15
24
33
50
15
23
17
26
20
30
18
27
19
29
D
2
PAK
SO-8
SO-8
SO-8
TO-220
TO-220
TO-220
TO-220
TO-220
TO-220
TO-220
Package
TO-220
Thermal
Resistance
Φ
JA
= 62
Φ
JA
= 75
Φ
JA
= 62
Φ
JA
= 62
Φ
JA
= 62
Φ
JA
= 62
Φ
JA
= 83
Φ
JA
= 83
Φ
JA
= 125
Φ
JA
= 125
Φ
JA
= 125
Φ
JA
= 40
Note:
1. R
DS(ON
) values at T
J
=125°C for most devices were extrapolated from the typical operating curves supplied by the
manufacturers and are approximations only. Only National Semiconductor offers maximum values at T
J
= 125°C.
8
RAYTHEON [ RAYTHEON COMPANY ]
