BQ2001-9R Power-One, BQ2001-9R Datasheet - Page 15

• Manufacturer Part Number: BQ2001-9R
• Description: BQ Series 97W Sinlge Ouput 5.1V DC/DC Converter
• Manufacturer: Power-One

Thermal Considerations and Protection
If a converter is located upright in free flowing, quasi-stationary
air (convection cooling) at the indicated maximum ambient
temperature T
is operated at its nominal input voltage and output power, the
temperature T
temperature (see Mechanical Data) will approach the indicated
value T
relationship between T
conditions of operation and integration into a system. The
thermal conditions are influenced by input voltage, output
current, airflow and temperature of surrounding components
and surfaces. T
indicative value only.
BCD20011-G Rev AD, 22-Dec-09
Current distribution in overload is dependent upon the type of
overload. A short-circuit in one output will cause the full current
flow into that output, whereas a resistive overload results in
more even distribution and in a reduced output voltage.
Efficiency
Fig. 16
Efficiency versus input voltage and output current (per
output). Typical values of EQ2320 at V
Hold-up Time
The Q Series converters provide virtually no hold-up time. If
hold-up time is required, use external output capacitors or
decoupling diodes together with input capacitors of adequate
size.
Formula for additional external input capacitor:
where as:
C
Caution: The installer must ensure that under all operating
conditions T
Temperature specifications.
Note: Sufficient forced cooling or an additional heat sink improves
the reliability or allows T
C
P
η
t
V
V
η [%]
80
85
75
90
i ext
h
o
i min
t i
i ext
= –––––––––––––––
1
C max
= external input capacitance [mF]
= output power [W]
= efficiency [%]
= hold-up time [ms]
= minimum input voltage [V]
= threshold level [V]
η • (V
2 • P
C
A max
C
o
ti
remains within the limits stated in the table
after the warm-up phase. However, the
• t
2
measured at the Measuring point of case
A max
– V
h
(see table Temperature specifications), and
2
• 100
i min
A
®
is therefore, contrary to T
to be higher than T
A
2
)
and T
3
C
depends heavily on the
o nom
A max
4
.
05115a
, as long as T
C max
5
V
V
V
I
o
i max
i nom
i min
C max
[A]
, an
Page 15 of 26
Fig. 17a
Output power derating versus T
A temperature sensor generates an internal inhibit signal,
which disables the outputs, if the case temperature exceeds
T
temperature drops below this limit. This feature is not fitted to
48Q models.
Output Power at Reduced Temperature
Operating BQ – GQ models with output current beyond I
requires a reduction of the ambient temperature T
forced cooling, in order to keep T
exceeded, the unit runs into its thermal protection and switches
off (e.g. T
Fig. 17b shows the operation of 48Q models beyond T
with forced cooling.
Fig. 17b
Output power derating versus T
C max
is not exceeded. In rack systems without proper thermal
management, the converters must not be packed too densely! In
such cases the use of a 5 or 6TE front panel is recommended.
Important: Short-term operation within the shaded area (e.g.
start-up current, peak current) is possible without additional
measures, provided the case temperature remains below T
0.45
0.4
. The outputs are automatically re-enabled if the
o max
o nom
o nom
o nom
o nom
A
66 – 132 Watt DC-DC Converter
> 50 °C and P
–10
o
A min
o
50
30
convection
convection
cooling
cooling
40
60
o
> P
Q Series Data Sheet
o nom
50
70
A
A
05116a
for BQ – GQ models
for 48Q models
C
). See fig. 17a.
below 85 °C. If T
60
80
cooling
05110b
forced
www.power-one.com
70
90
cooling
forced
100 °C
80 °C
A
C max
to 50 °C or
C max
A
= 50 °C
C max
C max
A
A
o nom
.
is