REV. OCT 24, 2003
Page 9 of 12
HHS6
DC
DC Series Data Shee
48Vdc In
ut, 6
m
Hal
Brick Converte
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 (# 4) 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 actually 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).
Remote Sense
The HHS60 Series converters have the capability to
remotely sense both lines of the output. This feature
moves the effective output voltage regulation point
from the output of the unit to the point of connection
of the remote sense pins. This feature automatically
adjusts the real output voltage of the converter in
order to compensate for voltage drops in distribution
and maintain a regulated voltage at the point of load.
This is shown in Figures 16 & 17.
If the remote sense feature is not to be used, the
sense pins should be connected locally. The
+Sense (#8) pin should be connected to the +Vout
(#9) pin directly at the output of the converter and the
–Sense (#6) pin should be connected to the -Vout
(#5) pin directly at the output of the converter.
If sense pins are not connected to load, or the
respective output pins, the converter will not be
damaged, but may not meet the output voltage
regulation specifications.
Output Voltage Trim
The trim feature allows the user to adjust the output
voltage from the nominal value. This can be used to
compensate for distribution drops, perform margining
in production, or accommodate other requirements
when output voltage needs to be adjusted from the
nominal value. There are two trim options available
in the HHS60 Series.
Negative Trim (No P/N suffix)
All HHS60 negative-trim models trim up with a
resistor connected from the TRIM (#7) pin to the
(-) Sense (#6) pin and trim down with a resistor from
the TRIM pin to the (+) Sense (#8) pin as shown in
Figure 16.
Figure 16. HHS60 Series Negative Trim Schematic
The following equation determines the required
external resistor value to obtain an output voltage
change of ∆%.
Vo*(100-∆%)-122.5
Rtrim-dn = R1*(--------------------------- ) - R2 KΩ
Vo*∆%
122.5*R1
Rtrim-up = (------------- - R2) KΩ
Vo*∆%
Where R1 and R2 are constants from the table
below
Model
R1 (kΩ) R2 (kΩ)
HHS60ZA 0. 223 0.15
HHS60ZB 0.474 1
HHS60ZD 1.039 3.92
HHS60ZE 4.220 5.11
