FEB 17, 2006 revised to JUL 25, 2006 Page 6 of 10 www.power-one.com\
HLS Series DC-DC Converter Data Sheet
48 VDC Input, 30 & 40 Amp Half-Bricks
Typical Application
Figure 6 shows the recommended connections for
the HLS Series converter.
Figure 6. Typical Application of HLS Series
The HLS 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 47 μF electrolytic
capacitor with the ESR<0.7Ω is recommended for
the HLS 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 one
10μF tantalum and one 1 μF ceramic capacitors
connected directly across the output pins of the
converter. Note, that the capacitors do not substitute
the filtering required by the load.
Shutdown Feature Description
The ON/OFF pin in the HLS Series converters
functions as a normal soft shutdown. It is referenced
to the –Vin pin (see Figure 6). With 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 insure 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
The trim feature allows the user to adjust the output
voltage from the nominal value. This can be used to
compensate distribution drops, perform margining in
production, or accommodate other requirements
when output voltage needs to be adjusted from the
nominal. There are two trim options available in the
HLS Series.
Negative-Trim (No P/N suffix)
All HLS negative-trim models trim up with a resistor
connected from the TRIM pin to the (-) Sense pin
and trim down with a resistor from the TRIM pin to
the (+) Sense pin as shown in Figure 7.
Figure 7. HLS Series Negative Trim Schematic
