FEATURES DESCRIPTIONS
FEATURES DESCRIPTIONS (CON.)
Remote On/Off
Output Voltage Programming
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.
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:
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).
10500
⎛
⎝
⎞
⎠
Rtrim :=
− 1000 ⋅Ω
Vo − 0.7525
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)
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:
10500
⎛
⎝
⎞
⎠
Vin
Vo
Rtrim :=
− 1000 ⋅Ω
2.5475
ION/OFF
RL
On/Off
Rtrim = 3.122 kΩ
GND
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:
Figure 22: Positive remote On/Off implementation
)
Vo
Vtrim := 0.7 − Vo − 0.7525 ⋅0.0667
Vin
⎣
⎦
Rpull-up
ION/OFF
RL
Vtrim is the external voltage in V
Vo is the desired output voltage
On/Off
GND
For example, to program the output voltage of a DNT
module to 3.3 Vdc, Vtrim is calculated as follows
Figure 23: Negative remote On/Off implementation
(
)
Vtrim := 0.7 − 2.5475⋅0.0667
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. ]
