INNOLINE
R-5xxxPA_DA
Series
DC/DC-Converter
Output Current vs Input Voltage
How to calculating the max output current
The internal power dissipation(PD)follows the equation:
PD = Io × Vo × (1-η)
Io = PD / Vo × (1-η)
90
85
80
Where
PD = Internal power dissipation
Io = Output current
Vo = Output voltage
η = Efficiency
60
40
20
Example: R-545.0P , at Vin = 18Vdc , Vo = 5Vdc ,η=93% (see table 1)
(a) When Ta = 60°C , PD = 1.4 Watt (see fig-1)
Io = 1.4(W) / 5(V) × (1-0.93) = 4(A)
(b) When Ta = 85°C , PD = 1 Watt (see fig-1)
Io = 1(W) / 5(V) × (1-0.93) = 2.857(A)
0
0.5
1
1.4
Internal Power Dissipation (W)
(c) At Vin = 12Vdc efficiency = 94% (see table 1)
When Ta = 85°C , PD = 1 Watt (see fig-1)
Io = 1(W) / 5(V) × (1-0.94) =3.33(A)
Characteristics
R-53xx / R-54xx
R-52xx / R-55xx
Output Voltage Line Regulation VS Vout
Output Voltage Line Regulation VS Vout
1
1
0.5
0.5
0
0
1.8
1.2
Output Voltage (V)
3.3
5.0
2.3
1.8
1.2
Output Voltage (V)
3.3
5.0
2.3
R-53xx / R-54xx
R-52xx / R-55xx
Intput Voltage Load Regulation VS Vin
Intput Voltage Load Regulation VS Vin
2.0
2.0
1.2V
1.8V
2.5V
3.3V
5.0V
1.5
1.0
0.5
1.5
1.0
0.5
1.2V
1.8V
2.5V
3.3V
5.0V
0
0
5
15
20
5
15
20
10
10
Input Voltage (V)
Input Voltage (V)
24-August-2005
www.recom-international.com
131
RECOM [ RECOM INTERNATIONAL POWER ]
