25-40W, DUAL OUTPUT DC/DC CONVERTERS
BPB Models
Temperature Derating and Electrical Performance Curves
D48 Models (40 Watts)
40
35
30
25
20
15
Natural Convection Cooling
10
150 Linear Feet Per Minute
300 Linear Feet Per Minute
5
0
–25 0 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Ambient Temperature (°C)
Figure 5a. Temperature Derating Without Heat Sink
40
35
30
25
20
15
Natural Convection Cooling
150 Linear Feet Per Minute
10
300 Linear Feet Per Minute
5
0
–25 0 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90
Ambient Temperature (°C)
Figure 5b. Temperature Derating With Heat Sink
Output Power
BPB Model, dual-output DC/DC converters incorporate a design tradeoff
between total available output power and input voltage range. The total
available power is a function of both the nominal input voltage and the
"width" of the input voltage range. For a given nominal input (24V or 48V),
narrower ranges (2:1 vs. 4:1) have more available power. For a given "width"
of input range (2:1 or 4:1), higher nominal inputs (48V vs. 24V) have more
available power. Each device, as indicated by its part-number suffix (Q12, Q48,
D24 or D48) has a total output power limitation of 25, 30, 35 or 40 Watts,
respectively. Observing these power limitations is the user's responsibility.
As indicated by its Part Number Structure, each ±5V, ±12V or ±15V BPB
device is capable of sourcing up to ±4, ±1.65 or ±1.3 Amps, respectively.
Users have the flexibility of loading either output up to these limits; however
you must be extremely careful not to exceed the total output power rating of
any given device. If, for example, a ±5V device with a 30W power rating
(BPB-5/4-Q48) is sourcing 4A from its +5V output (representing 20W of
+Output power), that device can only supply an additional 10W (2 Amps)
from its –Output.
As a consequence of this "power-allocation" flexibility, the definition of "full
load," as the condition under which performance specifications are tested and
listed, is ambiguous. The following table lists the positive and negative output
currents that DATEL uses to define each device’s "full load."
Model Number
BPB-5/4-Q12
BPB-5/4-Q48
BPB-5/4-D24
BPB-5/4-D48
BPB-12/1.65-Q12
BPB-12/1.65-Q48
BPB-12/1.65-D24
BPB-12/1.65-D48
BPB-15/1.3-Q12
BPB-15/1.3-Q48
BPB-15/1.3-D24
BPB-15/1.3-D48
Voltage
Range
10-36V
18-72V
18-36V
36-72V
10-36V
18-72V
18-36V
36-72V
10-36V
18-72V
18-36V
36-72V
Output
Power
25 Watts
30 Watts
35 Watts
40 Watts
25 Watts
30 Watts
35 Watts
40 Watts
25 Watts
30 Watts
35 Watts
40 Watts
Definition of "Full Load" for Specification Purposes
±5V Currents
±12V Currents
±15V Currents
±2.5A (25W)
±3A (30W)
±3.5A (35W)
±4A (40W)
–
–
–
–
–
–
–
–
–
–
–
–
±1.04A (24.96W)
±1.25A (30W)
±1.46A (35W)
±1.67A (40.1W)
–
–
–
–
–
–
–
–
–
–
–
–
±833mA (24.99W)
±1A (30W)
±1.17A (35.1W)
±1.33A (39.9W)
Table 1. Output Currents Comprising "Full Load"
5