FEATURES DESCRIPTIONS
Remote On/Off
The DNT series power modules have an On/Off pin for
remote On/Off operation. Both positive and negative
On/Off logic options are available in the DNT series
power modules.
For positive logic module, connect an open collector
(NPN) transistor or open drain (N channel) MOSFET
between the On/Off pin and the GND pin (see figure 22).
Positive logic On/Off signal turns the module ON during
the logic high and turns the module OFF during the logic
low. When the positive On/Off function is not used, leave
the pin floating or tie to Vin (module will be On).
For negative logic module, the On/Off pin is pulled high
with an external pull-up resistor (see figure 23) Negative
logic On/Off signal turns the module OFF during logic
high and turns the module ON during logic low. If the
negative On/Off function is not used, leave the pin
floating or tie to GND. (module will be On)
Vin
FEATURES DESCRIPTIONS (CON.)
Output Voltage Programming
The output voltage of the DNT can be programmed to any
voltage between 0.75Vdc and 5.5Vdc by connecting one
resistor (shown as Rtrim in Figure 25) between the TRIM
and GND pins of the module. Without this external
resistor, the output voltage of the module is 0.7525 Vdc.
To calculate the value of the resistor Rtrim for a particular
output voltage Vo, please use the following equation:
Rtrim
:=
⎜
⎛
10500
−
1000
⎞
⋅ Ω
⎝
Vo
−
0.7525
⎠
Rtrim is the external resistor in
Ω
Vo is the desired output voltage
For example, to program the output voltage of the DNT
module to 3.3Vdc, Rtrim is calculated as follows:
Rtrim
:=
⎜
Vo
I
ON/OFF
⎛
10500
−
1000
⎞
⋅ Ω
⎝
2.5475
⎠
On/Off
RL
Rtrim = 3.122 kΩ
DNT can also be programmed by applying a voltage
between the TRIM and GND pins (Figure 26). The
following equation can be used to determine the value of
Vtrim needed for a desired output voltage Vo:
Vtrim
:=
0.7
−
⎡
(
Vo
−
0.7525
)
⋅
0.0667
⎤
⎣
⎦
GND
Figure 22:
Positive remote On/Off implementation
Vin
Rpull-up
I
ON/OFF
Vo
On/Off
RL
Vtrim is the external voltage in V
Vo is the desired output voltage
For example, to program the output voltage of a DNT
module to 3.3 Vdc, Vtrim is calculated as follows
Vtrim
:=
0.7
−
(
2.5475
⋅
0.0667
)
GND
Figure 23:
Negative remote On/Off implementation
Over-Current Protection
To provide protection in an output over load fault
condition, the unit is equipped with internal over-current
protection. When the over-current protection is
triggered, the unit enters hiccup mode. The units
operate normally once the fault condition is removed.
DS_DNT12SMD03_06252007
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DELTA [ DELTA ELECTRONICS, INC. ]
