FEATURES DESCRIPTIONS
Remote On/Off
The DCM 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 DCM series
power modules.
For negative 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 28).
Negative logic On/Off signal turns the module ON during
the logic low and turns the module OFF during the logic
high. When the negative On/Off function is not used, tie
the pin to GND (module will be On).
For positive logic module, the On/Off pin is pulled high
with an external pull-up 5kΩ resistor (see figure 29).
Positive logic On/Off signal turns the module ON during
logic high and turns the module OFF during logic low. If
the Positive On/Off function is not used, tie the pin to Vin.
(module will be On)
V in
Vo
Remote Sense
The DCM 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.
Distribution Losses
Vin
Vo
Distribution Losses
Sense
RL
GND
Distribution
Losses
Distribution
Losses
Figure 30:
Effective circuit configuration for remote sense
operation
Output Voltage Programming
The output voltage of the DCM can be programmed to
any voltage between 0.6Vdc and 3.3Vdc by connecting
one resistor (shown as Rtrim in Figure 31) between the
TRIM and GND pins of the module. Without this external
resistor, the output voltage of the module is 0.6 Vdc. To
calculate the value of the resistor Rtrim for a particular
output voltage Vo, please use the following equation:
I
O N /O F F
O n/O ff
Q1
GND
RL
Figure 28:
Negaitive remote On/Off implementation
V in
R pull-
up
I
O N /O FF
1.2
Rtrim
½
k
Vo
0.6
For example, to program the output voltage of the DCM
module to 1.8Vdc, Rtrim is calculated as follows:
Vo
O n/O ff
RL
1.2
Rtrim
½
k
½
1
K
1.8
0.6
Vo
Q1
GND
RLoad
Figure 29:
Positive remote On/Off implementation
GND
TRIM
Rtrim
Figure 31:
Circuit configuration for programming output voltage
using an external resistor
DS_ DCM04S0A0S12PFA_10022013
E-mail: DCDC@delta.com.tw
http://www.deltaww.com/dcdc
P8
DELTA [ DELTA ELECTRONICS, INC. ]
