Feature description, Remote on/off, Input undervoltage lockout – GE Industrial Solutions HW-HC004-005-006 Series User Manual

Page 17: Over voltage protection

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Data Sheet

October 4, 2013

HW/HC004/005/006 Series DC-DC Power Module:

18-36Vdc & 36-75Vdc Input; 1.0V-5Vdc Output; 4A - 6A Output Current

LINEAGE

POWER

17

Feature Description

Remote On/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.

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.

ON/OFF

V

IN

(+)

V

IN

(-)

I

on/off

V

on/off

V

O

COM

Figure 64. Remote On/Off Implementation.

To turn the power module on and off, the user must
supply a switch (open collector or equivalent) to control
the voltage (V

on/off

) between the ON/OFF terminal and

the V

IN

(-) terminal. Logic low is 0V

≤ V

on/off

≤ 1.2V. The

maximum I

on/off

during a logic low is 1mA, the switch

should be maintain a logic low level whilst sinking this
current.

During a logic high, the typical V

on/off

generated by the

module is 5.8V, and the maximum allowable leakage
current at V

on/off

= 5.8V is 10μA.

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 V

IN

(-).

Overcurrent Protection

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%
I

O, max

.

Input Undervoltage Lockout

At input voltages below the input undervoltage lockout
limit, the module operation is disabled. The module will

only begin to operate once the input voltage is raised
above the undervoltage lockout turn-on threshold,
V

UV/ON

.

Once operating, the module will continue to operate until
the input voltage is taken below the undervoltage turn-off
threshold, V

UV/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.

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

o

C is

exceeded at the thermal reference point T

ref

. Once the

unit goes into thermal shutdown it will then wait to cool
before attempting to restart.

Output Voltage Programming

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 V

O

(+) pin or the V

O

(-) pin (COM pin) .

V

O

(+)

V

O

TRIM

COM

R

trim-down

LOAD

V

IN

(+)

ON/OFF

V

IN

(-)

R

trim-up

Figure 65. Circuit Configuration to Trim Output
Voltage.

Connecting an external resistor (R

trim-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%.

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