14
Advanced output module features
Remote voltage programming (External voltage control)
The output voltage of the module can be adjusted using an external voltage source connected between the COM and V
control
pins on the signals connector (J5) as shown below.
In this configuration the output voltage will follow the equation below,
V
o
= V
set
((1.8 - V
ctrl
) / 0.6), where V
set
is the manual preset voltage of the module.
The output voltage can be controlled from 0% to 300% of the preset voltage using this control method. However, care must
be taken to ensure the output voltage does not exceeed the OVP level, as this is considered a safety hazzard and will latch the
entire unit off. To determine the level of control voltage that will trigger OVP, insert Vovp into the equation above.
Example:
V
OVP
= 9.5 V, V
set
= 5 V;
V
ctrl
= 1.8-(V
OVP
*0.6/V
set
) = 0.66 V
Hence, V
ctrl
should never fall below 0.66 V, otherwise OVP may latch the entire unit off.
Alternatively, by manually adjusting the output voltage to less than 1/3
rd
of the OVP voltage ensures that OVP can never be
tripped by remote voltage control.
Care must be taken to esure the output voltage won’t be forced too far below the V
MIN
limit under maximum load operating
conditions. Fail doing so, can lead to the output module electrical overstress and consequent damage.
Also, remote adjustment of the output voltage using the V
control
pin does not affect the preset power good threshold. Hence,
remotely adjusting the output voltage below 0.9*V
set
will cause the power good signal to go low.
A
DVANCED
O
UTPUT
M
ODULE
F
EATURES
