Data Sheet
HW/HC004/005/006 Series DC-DC Power Module:
May 16, 2008
18-36Vdc & 36-75Vdc Input; 1.0V-5Vdc Output; 4A - 6A Output Current
only begin to operate once the input voltage is raised
Feature Description
above the undervoltage lockout turn-on threshold,
VUV/ON
Remote On/Off
.
Once operating, the module will continue to operate until
the input voltage is taken below the undervoltage turn-off
Two remote on/off options are available. Positive logic
turns the module on during a logic high voltage on the
ON/OFF pin, and off during a logic low. Negative logic
remote On/Off, device code suffix “1”, turns the module
off during a logic high and on during a logic low.
threshold, VUV/OFF
.
Over Voltage Protection
The output overvoltage protection consists of circuitry
that internally clamps the output voltage. If a more
accurate output overvoltage protection scheme is
required then this should be implemented externally via
use of the remote on/off pin.
To maintain compatibility with LW series power modules
the Remote On/Off pin is optional for the TH (through
hole) version. Standard TH modules have no On/Off pin
fitted. TH modules ordered with device code suffix “1”
are negative logic with the On/Off pin fitted.
Over Temperature Protection
To provide protection in a fault condition, the unit is
equipped with a thermal shutdown circuit. The unit will
shutdown if the overtemperature threshold of 125 oC is
exceeded at the thermal reference point Tref . Once the
unit goes into thermal shutdown it will then wait to cool
before attempting to restart.
VIN(+)
VO
Ion/off
ON/OFF
Von/off
Output Voltage Programming
COM
Trimming allows the output voltage set point to be
increased or decreased, this is accomplished by
connecting an external resistor between the TRIM pin
and either the VO(+) pin or the VO(-) pin (COM pin) .
VIN(-)
VIN(+)
VO(+)
VOTRIM
COM
Figure 64. Remote On/Off Implementation.
Rtrim-up
To turn the power module on and off, the user must
supply a switch (open collector or equivalent) to control
the voltage (Von/off) between the ON/OFF terminal and
the VIN(-) terminal. Logic low is 0V ≤ Von/off ≤ 1.2V. The
maximum Ion/off during a logic low is 1mA, the switch
should be maintain a logic low level whilst sinking this
current.
ON/OFF
LOAD
Rtrim-down
VIN(-)
During a logic high, the typical Von/off generated by the
module is 5.8V, and the maximum allowable leakage
current at Von/off = 5.8V is 10μA.
Figure 65. Circuit Configuration to Trim Output
Voltage.
If not using the remote on/off feature:
For positive logic, leave the ON/OFF pin open.
For negative logic, short the ON/OFF pin to VIN(-).
Overcurrent Protection
Connecting an external resistor (Rtrim-down) between the
TRIM pin and the COM pin decreases the output voltage
set point. To maintain set point accuracy, the trim
resistor tolerance should be ±0.1%.
To provide protection in a fault (output overload)
condition, the unit is equipped with internal
current-limiting circuitry and can endure current limiting
continuously. At the point of current-limit inception, the
unit enters hiccup mode. The unit operates normally
once the output current is brought back into its specified
range. The average output current during hiccup is 10%
IO, max
.
Input Undervoltage Lockout
At input voltages below the input undervoltage lockout
limit, the module operation is disabled. The module will
LINEAGE POWER
17
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
