Datasheet

DS_DCT12S0A0S03NFA_11142013
12
FEATURES DESCRIPTIONS (CON.)
Remote Sense
The DCT provide Vo remote sensing to achieve proper
regulation at the load points and reduce effects of
distribution losses on output line. In the event of an open
remote sense line, the module shall maintain local sense
regulation through an internal resistor. The module shall
correct for a total of 0.5V of loss. The remote sense line
impedance shall be < 10.
Vo
Sense
Vin
GND
RL
Distribution Losses
Distribution Losses
Distribution
Losses
Distribution
Losses
Figure 34: Effective circuit configuration for remote sense
operation
Output Voltage Programming
The output voltage of the DCT can be programmed to any
voltage between 0.59Vdc and 5.0Vdc by connecting one
resistor (shown as Rtrim in Figure 35) between the TRIM
and GND pins of the module. Without this external
resistor, the output voltage of the module is 0.59 Vdc. To
calculate the value of the resistor Rtrim for a particular
output voltage Vo, please use the following equation:








 K
Vo
Rtrim
591.0
91.5
Rtrim is the external resistor in kΩ
Vo is the desired output voltage.
For example, to program the output voltage of the DCT
module to 5.0Vdc, Rtrim is calculated as follows:








 KKRtrim 34.1
591.00.5
91.5
Vo
TRIM
GND
RLoad
Rtrim
Figure 35: Circuit configuration for programming output voltage
using an external resistor
Table 1 provides Rtrim values required for some common
output voltages, By using a 0.5% tolerance trim resistor, set
point tolerance of ±1.5% can be achieved as specified in
the electrical specification.
Table 1
Vo(V) Rtrim(KΩ)
0.590 Open
0.600 656.700
1.000 14.450
1.200 9.704
1.500 6.502
1.800 4.888
2.500 3.096
3.300 2.182
5.000 1.340
Certain restrictions apply on the output voltage set point
depending on the input voltage. These are shown in the
Output Voltage vs. Input Voltage Set Point Area plot in
Figure 36. The Upper Limit curve shows that for output
voltages of 0.9V and lower, the input voltage must be lower
than the maximum of 14V. The Lower Limit curve shows
that for output voltages of 3.8V and higher, the input voltage
needs to be larger than the minimum of 4.5V.
Figure 36: Output Voltage vs. Input Voltage Set Point Area plot
showing limits where the output voltage can be set for different
input voltages.