Q48T20050-NBB0 POWER ONE, Q48T20050-NBB0 Datasheet - Page 7

• Manufacturer Part Number: Q48T20050-NBB0
• Manufacturer: POWER ONE
• Type: Step Downr

Specifications of Q48T20050-NBB0

• Number Of Outputs: 1
• Output Current: 20A
• Input Voltage: 48V
• Output Voltage: 5V
• Screening Level: Industrial
• Product Length (mm): 36.83mm
• Product Height (mm): 6.52mm
• Product Depth (mm): 58.42mm
• Mounting Style: Through Hole
• Pin Count: 8
• Package / Case: Quarter-Brick
• Lead Free Status / Rohs Status: Not Compliant

When using remote sense, the output voltage at the con-
verter can be increased by as much as 10% above the
nominal rating in order to maintain the required voltage
across the load. Therefore, the designer must, if necessary,
decrease the maximum current (originally obtained from the
derating curves) by the same percentage to ensure the con-
verter’s actual output power remains at or below the maxi-
mum allowable output power.
Output Voltage Adjust /TRIM (Pin 6)
The converter’s output voltage can be adjusted up 10% or
down 20% relative to the rated output voltage by the addition
of an externally connected resistor.
The TRIM pin should be left open if trimming is not being
used. To minimize noise pickup, a 0.1 µF capacitor is con-
nected internally between the TRIM and SENSE(-) pins.
To increase the output voltage, refer to Fig. 4. A trim resistor,
R
SENSE(+) (Pin 7), with a value of:
where,
When trimming up, care must be taken not to exceed the
converter‘s maximum allowable output power. See previous
section for a complete discussion of this requirement.
To decrease the output voltage (Fig. 5), a trim resistor,
R
SENSE(-) (Pin 5), with a value of:
where,
NOV 07, 2003 revised to NOV 20, 2006
R
R
R
V
Δ
V
T-INCR
T-DECR
T
T
T
O
O
−
−
=
−INCR
INCR
−NOM
−REQ
DECR
(V
, should be connected between the TRIM (Pin 6) and
=
=
, should be connected between the TRIM (Pin 6) and
O
=
=
=
5.11(100
-
511
REQ
Required value of trim-up resistor k Ω ]
Nominal value of output voltage [V]
Desired (trimmed) output voltage [V].
Δ
V
O
−
−
-
NOM
V
10.22
O
-
+
NOM
1.225Δ
Δ)V
)
[k Ω ]
O
X
−
NOM
100
−
626
[%]
Q48T20050 and Q48S20050 DC-DC Converter Data Sheet
−
10.22
[k Ω ]
Page 7 of 15
36-75 VDC Input; 5.0 VDC @ 20A Output
and Δ is as defined above.
Note: The above equations for calculation of trim resistor
values match those typically used in conventional industry-
standard quarter bricks.
Trimming/sensing beyond 110% of the rated output voltage
is not an acceptable design practice, as this condition could
cause unwanted triggering of the output over-voltage protec-
tion (OVP) circuit. The designer should ensure that the dif-
ference between the voltages across the converter’s output
pins and its sense pins does not exceed 0.50 V, or:
This equation is applicable for any condition of output sens-
ing and/or output trim.
R
[V
T
OUT
−DECR
Vin
Vin
(
+
Fig. 5: Configuration for decreasing output voltage.
)
Fig. 4: Configuration for increasing output voltage.
=
−
Required value of trim-down resistor [k Ω ]
V
OUT
(
−
Vin (+)
ON/OFF
Vin (+)
ON/OFF
)]
Vin (-)
Vin (-)
−
[V
SENSE
(Top View)
(Top View)
Q
Converter
Q
Converter
TM
TM
(
Family
Family
+
)
−
V
SENSE
SENSE (+)
SENSE (+)
SENSE (-)
SENSE (-)
www.power-one.com
Vout (+)
Vout (+)
Vout (-)
Vout (-)
(
TRIM
TRIM
−
)]
≤
0.50
R
R
T-INCR
T-DECR
[V]
Rload
Rload