Q48SP12017NRFA Datasheet, PDF (9/13 Pages) Delta Electronics, Inc. – Delphi Series Q48SP, 216W Quarter Brick Family DC/DC Power Modules: 48V in, 12V/18A out

FEATURES DESCRIPTIONS (CON.)
Output Voltage Adjustment (TRIM)
To increase or decrease the output voltage set point,
connect an external resistor between the TRIM pin
and either the SENSE(+) or SENSE(-). The TRIM pin
should be left open if this feature is not used.
Figure 17: Circuit configuration for trim-up (increase output
voltage)
If the external resistor is connected between the TRIM
and SENSE (+) pins, the output voltage set point
increases (Fig. 17). The external resistor value
required to obtain a percentage of output voltage
change △% is defined as:
Rtrim _ up = ((5.11^{×Vo(100 + ∆)} − ⁵¹¹ −10.22)(KΩ)
1.225∆
∆
Vnom − Vadj
∆=(
) ×100
Vnom
Vo=Nominal voltage
Ex. When trim up to 13.2V from 12V
Rtrim − up = ^{5.11×12(100 +10)} − ⁵¹¹ −10.22
1.225 ×10
10
⇒ ^{= 489.3KΩ}
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
1 2 3 4 5 6 7 8 9 10
Trim-Up percentage
Figure 18: Trim UP resistor selection
Figure 19: Circuit configuration for trim-down (decrease
output voltage)
If the external resistor is connected between the TRIM
and SENSE (-) the output voltage set point decreases
(Fig. 19). The external resistor value required to obtain
a percentage output voltage change △% is defined
as:
Rtrim_down(∆) = (511 −10.22)kΩ
∆
Ex. When trim down to 9.6V from 12V
Rtrim − down = ⁵¹¹ −10.22KΩ = 15.33KΩ
20
550
500
450
400
350
300
250
200
150
100
50
0
1
10
100
Trim-Down percentage
Figure 20: Trim DOWN resistor selection
The output voltage can be increased by both the remote
sense and the trim, however the maximum allowed
increase is the larger of either the remote sense spec or
the trim spec, not the sum of both.
When using remote sense and trim, the output voltage
of the module is usually increased, which increases the
power output of the module with the same output
current.
Care should be taken to ensure that the maximum
output power of the module remains at or below the
maximum rated power.
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DS_Q48SP12017_01162007