SQ48T10050-NBC0 POWER ONE, SQ48T10050-NBC0 Datasheet - Page 3
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SQ48T10050-NBC0
Manufacturer Part Number
SQ48T10050-NBC0
Description
Manufacturer
POWER ONE
Type
Step Downr
Datasheet
1.SQ48T10050-NBC0.pdf
(64 pages)
Specifications of SQ48T10050-NBC0
Output Power
50W
Output Current
10A
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
Number Of Outputs
1
Package / Case
1/8-Brick
Lead Free Status / RoHS Status
Not Compliant
Operations
Input and Output Impedance
These power converters have been designed to be
stable with no external capacitors when used in low
inductance input and output circuits.
In many applications, the inductance associated with
the distribution from the power source to the input of
the converter can affect the stability of the converter.
The addition of a 33 µF electrolytic capacitor with an
ESR < 1 Ω across the input helps to ensure stability
of the converter. In many applications, the user has
to use decoupling capacitance at the load. The
power converter will exhibit stable operation with
external load capacitance up to 1000 µF on 12 V,
2,200 µF on 8.0 V, 10,000 µF on 5.0 – 6.0 V, and
15,000 µF on 3.3 – 1.0 V outputs.
Additionally, see the EMC section of this data sheet
for discussion of other external components which
may be required for control of conducted emissions.
ON/OFF (Pin 2)
The ON/OFF pin is used to turn the power converter
on or off remotely via a system signal. There are two
remote control options available, positive logic and
negative logic, with both referenced to Vin(-). A
typical connection is shown in Fig. A.
The positive logic version turns on when the ON/OFF
pin is at a logic high and turns off when at a logic low.
The converter is on when the ON/OFF pin is left
open. See Electrical Specifications for logic high/low
definitions.
The negative logic version turns on when the pin is at
a logic low and turns off when the pin is at a logic
high. The ON/OFF pin can be hardwired directly to
Vin(-) to enable automatic power up of the converter
without the need of an external control signal.
The ON/OFF pin is internally pulled up to 5V through
a resistor. A properly debounced mechanical switch,
open collector transistor, or FET can be used to drive
the input of the ON/OFF pin. The device must be
capable of sinking up to 0.2 mA at a low level voltage
SEP 14, 2005 revised to NOV 06, 2006
Vin
CONTROL
Fig. A: Circuit configuration for ON/OFF function.
INPUT
ON/OFF
Vin (+)
Vin (-)
Semi
Converter
(Top View)
Q
TM
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SENSE (+)
SENSE (-)
Vout (+)
Vout (-)
TRIM
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Page 3 of 64
36-75 VDC Input; 1.0-12 VDC Output
of ≤ 0.8 V. An external voltage source (±20 V
maximum) may be connected directly to the ON/OFF
input, in which case it must be capable of sourcing or
sinking up to 1 mA depending on the signal polarity.
See the Startup Information section for system timing
waveforms associated with use of the ON/OFF pin.
Remote Sense (Pins 5 and 7)
The
compensates for voltage drops occurring between the
output pins of the converter and the load. The
SENSE(-) (Pin 5) and SENSE(+) (Pin 7) pins should
be connected at the load or at the point where
regulation is required (see Fig. B).
If remote sensing is not utilized, the SENSE(-) pin must be
connected to the Vout(-) pin (Pin 4), and the SENSE(+) pin
must be connected to the Vout(+) pin (Pin 8) to ensure the
converter will regulate at the specified output voltage. If these
connections are not made, the converter will deliver an output
voltage that is slightly higher than the specified data sheet
value.
Because the sense leads carry minimal current, large
traces on the end-user board are not required.
However, sense traces should be run side by side and
located close to a ground plane to minimize system
noise and ensure optimum performance.
When
converter’s output overvoltage protection (OVP)
senses the voltage across Vout(+) and Vout(-), and
not across the sense lines, so the resistance (and
resulting voltage drop) between the output pins of the
converter and the load should be minimized to
prevent unwanted triggering of the OVP.
When utilizing the remote sense feature, care must be
taken not to exceed the maximum allowable output
power capability of the converter, which is equal to the
product of the nominal output voltage and the
allowable output current for the given conditions.
When using remote sense, the output voltage at the
converter can be increased by as much as 10%
above the nominal rating in order to maintain the
required voltage across the load. Therefore, the
Vin
remote
SQ48 DC-DC Series Data Sheet
using
Fig. B: Remote sense circuit configuration.
ON/OFF
Vin (+)
Vin (-)
sense
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Semi
CAUTION
remote
Converter
(Top View)
feature
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SENSE (+)
sense
SENSE (-)
Vout (+)
Vout (-)
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