Data Sheet
EQD020 Series Single Output: Eighth Brick Power Modules:
19-60Vdc Input; 3.3Vdc Output; 66W
November 9, 2006
Feature Descriptions (continued)
Pre-Bias Immunity
Output Voltage Programming
The modules are able to start into a pre-biased output
with a monotonic rise of the output voltage. During
shutdown an internal feature implemented in the
module ensures there will be no reverse current.
The output voltage is adjustable +10% to -10% of
3.3V. A resistor placed between the Trim pin and
Sense (+) increases the output voltage and a resistor
placed between the Trim pin and Sense (-) decreases
the output voltage. Figure 21 shows the circuit
configuration using an external resistor. The trim
resistor should be positioned close to the module. If
the trim pin is not used then the pin shall be left open.
The following equations determine the required
external resistor value to obtain a percentage output
voltage change of Δ%.
To decrease output voltage set point:
510
⎛
⎜
⎞
⎠
Rtrim − down
=
−10.2 KΩ
⎟
Δ%
⎝
Where,
V
o, nom −Vdesired
Δ% =
×100
Vo, nom
Vdesired = Desired output voltage set point (V).
To increase the output voltage set point
5.1*Vo, nom
*
100+ Δ%
)
510
⎛
⎜
⎞
Rtrim − up
=
−
−10.2 KΩ
⎟
1.225*Δ%
Δ%
⎝
⎠
Although the output voltage can be increased by both
the remote sense and by the trim, the maximum
increase for the output voltage is not the sum of both.
The maximum absolute increase in output voltage,
due to simultaneous remote sense and trim
increases, shall not exceed the larger of the specified
individual remote sense or trim maximum limits shown
in the Features Specifications table.
VO(+)
VIN(+)
SENSE (+)
Rtrim-up
ON/OFF
LOAD
TRIM
Rtrim-down
SENSE (-)
VO(-)
VIN(-)
Figure 21. Circuit Configuration to program output
voltage using an external resistor.
Tyco Electronics Power Systems
10
LINEAGEPOWER [ LINEAGE POWER CORPORATION ]
