HBC25ZH-NT Datasheet, PDF (4/7 Pages) Power-One – HBC DC-DC Series Data Sheet 300-Watt Half-Brick Converters

HBC DC-DC Series Data Sheet
300-Watt Half-Brick Converters
Efficiency Curves
95
90
85
80
75
0
36V
48V
75V
20 40 60 80 100
LOAD %
Figure 1. HBC25ZH Efficiency vs. Output Load
Typical Application
Figure 2 shows the recommended connections for the
HBC Series converter.
Fuse
C1
HBC25ZH
+Vi
O n/O ff
+Vo
+Sense
Trim
C2 C3
-Sense
-Vi
-Vo
Figure 2. Typical Application of HBC Series
The HBC Series converters do not require any external
components for proper operation. However, if the
distribution of the input voltage to the converter contains
significant inductance, the capacitor C1 may be
required to enhance performance of the converter. A
minimum of a 68µF electrolytic capacitor with the
ESR<0.7Ω is recommended for the HBC Series.
Refer to the “Inrush Current Control Application Note”
on www.power-one.com for suggestions on how to limit
the magnitude of the inrush current.
For output decoupling we recommend using a
10µF low ESR tantalum capacitor
(AVX TPSC106M025R0500 is used in our test
setup) and a 1µF ceramic capacitor. Note, that
the capacitors do not substitute the filtering
required by the load.
Shutdown Feature Description
The ON/OFF pin in the HBC Series converters
functions as a normal soft shutdown. It is
referenced to the –Vin pin (see Figure 2). With
the positive logic, when the ON/OFF pin is pulled
low, the output is turned off and the unit goes into
a very low input power mode.
With negative logic, when the ON/OFF pin is
pulled low, the unit is turned on.
An open collector switch is recommended to
control the voltage between the ON/OFF pin and
the -Vin pin of the converter. The ON/OFF pin is
pulled up internally, so no external voltage source
is required. The user should avoid connecting a
resistor between the ON/OFF pin and the +Vin
pin.
When the ON/OFF pin is used to achieve remote
control, the user must take care to ensure that the
pin reference for the control is really the -Vin pin.
The control signal must not be referenced ahead
of EMI filtering, or remotely from the unit.
Optically coupling the information and locating the
optical coupler directly at the module will solve
any of these problems.
Note:
If the ON/OFF pin is not used, it can be left floating (positive
logic), or connected to the -Vin pin (negative logic).
OUTPUT VOLTAGE TRIM
Industry Standard Positive Trim (suffix –T)
The -T option units trim up with a resistor from the
Trim (#7) pin to the +Sense (#8) pin and trim
down with a resistor from the Trim (#7) pin to the
–Sense (#6) pin as shown in Figure 3.
REV. DEC 15, 2003
www.power-one.com
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