CANDD NCX10S24050 Isolated 10w single output dc/dc converter Datasheet

NCX10S SERIES
Isolated 10W Single Output DC/DC Converters
Nominal
Input Voltage
Output Voltage
Output Current
Power Consumption
at 0% Load
Power Consumption
at Shutdown
Efficiency (MIN)
Isolation
Capacitance
SELECTION GUIDE1
V
24
24
48
48
24
24
48
48
V
3.4
5.1
3.4
5.1
3.4
5.1
3.4
5.1
A
3.1
2.0
3.1
2.0
3.1
2.0
3.1
2.0
mW
270
280
500
510
270
280
500
510
mW
26
25
44
45
26
25
44
45
%
78
82
79
82
78
82
79
82
pF
23
26
29
32
23
26
29
32
Order Code
NCX10S24033
NCX10S24050
NCX10S48033
FEATURES
NCX10S48050
■ High Efficiency to 82%
NCX10S24033Y
■ 500V Input to Output Isolation
■ Industry Standard Pinout
■ UL 60950 Recognition Pending
■ Non Latching Current Limit
■ Constant 400kHz Frequency
■ Versatile Control Options
■ Continuous Rating to 10W @85°C
■ Operation to Zero Load
■ Protected Against Load Faults
■ Internal Over Temperature Protection
■ Uses No Electrolytic Capacitors
DESCRIPTION
The NCX10S series of DC/DC Converters
combines ease of application with versatility
and is available in two pin patterns based on
popular industry standards. High efficiency
enables full rating to be achieved in a small
package without heatsinking, and a high
surge capability will provide for start-up and
transient loads, whilst being thermally
protected against sustained overload. The
NCX10S series is currently undergoing
testing by Underwriters Laboratory (UL) to UL
60950 for functional insulation.
NCX10S24050Y
NCX10S48033Y
NCX10S48050Y
INPUT CHARACTERISTICS1
Parameter
Conditions
Voltage Range
Continuous operation, 24V input types
Continuous operation, 48V input types
MIN
NOM
MAX
Units
18
36
24
48
36
75
V
OUTPUT CHARACTERISTICS1
Parameter
Conditions
MIN
TYP
Voltage Set Point Error 50% load
Substrate temperature –40 to 110°C
Overall
Load 0% - 100%
Voltage Error
Input specified range
Temperature Coefficient
of Output Voltage
(slope)
Deviation of
Temperature MIN - MAX
Output Voltage
Current Limit
Continuous short circuit causes no damage
NCX10S24033
Overload
95% of nominal NCX10S24050
Output Current
output voltage
NCX10S48033
NCX10S48050
Line Regulation
Operating voltage range, 50% load
Load Regulation
0% - 100% rated load2
Ripple
rms
MAX
Units
1.0
%
2.5
%
250
ppm°C
1.0
%
153
170
148
164
% of
rated
Output
Current
0.1
0.5
1.0
%
%
%
TYP
MAX
Units
-0.3
0
1.5
2.6
5.0
6.1
10
ms
360
400
440
kHz
CONTROL CHARACTERISTICS
Parameter
Conditions
Voltage Trimming
Range
Remote Switch Input
(voltage relative
to input negative)
At rated load,
Trim control at either output
Not operating
Operating, open circuit voltage
VIN MIN to MAX
Time from application of valid input
voltage to output being in specification
Start Delay
Switching Frequency
MIN
±10
%
V
ABSOLUTE MAXIMUM RATINGS
Input voltage, 24V input types
Input voltage, 48V input types
Output Voltage
Output trim control
Shutdown control
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–0.3V to 40V
–0.3V to 80V
–0.3V to regulated voltage
–1V to +30V relative to output return
–0.3V to 6V relative to input return
1 Specifications typical at TA=25°C, nominal input voltage and rated output current unless otherwise specified.
2 A minimum load of 10% of rating is recommended for typical applications, see application notes.
NCX10S SERIES
Isolated 10W Single Output DC/DC Converters
ISOLATION CHARACTERISTICS
Parameter
Conditions
Isolation Voltage
Resistance
Flash tested for 1 second
VISO=500VDC
MIN
TYP
MAX
1000
1
Units
VDC
GΩ
ENVIRONMENTAL CHARACTERISTICS
Parameter
Conditions
MIN
Substrate Temp.
Full load
Storage
Absolute MAX internal temperature
Thermal Protection Operates at substrate temperature
TYP
MAX
Units
125
125
°C
°C
°C
–40
–40
150
THERMAL PERFORMANCE
NCX10S24050
NCX10S48033
11
11
10
10
10
9
8
7
6
5
4
-40
Still Air
100lfm
200lfm
300lfm
400lfm
10
60
Ambient Temperature (°C)
110
Ambient Power (W)
11
Ambient Power (W)
Ambient Power (W)
NCX10S24033
9
8
7
6
Still Air
100lfm
200lfm
300lfm
5
4
-40
10
60
Ambient Temperature (°C)
9
8
Still Air
100lfm
200lfm
7
6
5
4
-40
110
10
60
Ambient Temperature (°C)
110
NCX10S48050
11
Ambient Power (W)
10
UL 60950 RECOGNITION (Maximum permissable load in still air)
9
8
7
6
Still Air
100lfm
5
4
-40
10
60
Ambient Temperature (°C)
Part Number
-40°C
25°C
70°C
75°C
80°C
85°C
90°C
Units
NCX10S24033
NCX10S24050
NCX10S48033
NCX10S48050
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
10.0
9.0
10.0
9.5
10.0
7.9
8.9
8.4
10.0
6.5
7.2
7.1
9.6
5.0
5.2
5.5
8.0
W
110
APPLICATION NOTES
In a typical application, the NCX10S series
of DC/DC converters require nothing more
than a dc supply of correct polarity and
voltage to generate its specified output. These
notes are intended to offer help in the use of
other facilities offered by these converters,
and to provide assistance in achieving their
full potential.
VOLTAGE TRIMMING
The trimming (adjust) input on the secondary
side allows output voltage adjustment within
the capability of the power circuit.
When open circuit, the trimming pin ADJ
operates at near half the output voltage. A
basic trimming arrangement consists of a
potentiometer of 10kΩ to 100kΩ connected
across the output, with its wiper connected to
the ADJ pin (see figure 1). Dependent on
model, the output will be reduced by about
15% when the wiper is at the positive output,
or increased by about 24% when at the
negative rail. Regulation will be maintained to
at least 10% adjustment either way.
If finer adjustment is required, a resistor may
be included between the wiper and the pin.
For example, 62kΩ will restrict a 3.3V model
to ±5% adjustment range. The corresponding
values for the 5V model is 56kΩ.
+VIN
+VOUT
DC
ADJ
100KΩ
–VIN
Figure 1: Voltage Trimming
DC
0V
NCX10S SERIES
Isolated 10W Single Output DC/DC Converters
APPLICATION NOTES
OTHER TRIMMING FUNCTIONS
The voltage applied to the trim pin need not
be from a potentiometer. The trim facility may
be driven electronically to provide
“margining”, remote sense, active load
sharing, current control or remote
programming (There is a minimum output
voltage below which control is not possible).
SHUTDOWN & UNDER VOLTAGE TRIM
When the shutdown pin (Pin 11) is shorted to
the negative input, the converter will stop. Its
current consumption will then be less than
1mA at nominal supply voltage. The
shutdown/UV adjust pin serves the dual
function of shutting the converter down into a
low power state, and allowing adjustment of
the under voltage start threshold.
To shut the unit down this pin should be taken
to below 1.5V, using either an isolating
diode (figure 2) with the anode connected to
the shutdown pin or using an open collector
pulldown (figure 3).
The UV threshold can be controlled either via
a resistor connected between the pin and 0V,
or by connecting a series 1MΩ resistor to a
voltage of between 0V and 2.5V.
in figures 4 & 5. Note that voltage should not
be applied directly to the pin without a series
resistor or diode.
If the shutdown pin is to be connected to a
long wire, it is recommended that a capacitor
decouples the pin to the supply common in
order to avoid the risk of injecting noise into
the converter circuit. A series resistor may
also be helpful. Values of 10nF and 1kΩ may
be used.
Many converters may be switched together
simply by linking the primary control pins via
a schottky signal diode anode to the control
pin. The primary common pins must also be
linked, see figure 6.
FILTERING
The module includes a basic level of filtering,
sufficient for many applications. Where lower
noise levels are desired, filters can easily be
added to achieve any required noise
performance.
A DC/DC converter generates noise in two
principle forms: that which is radiated from
its body and that conducted on its external
connections. There are three separate modes
of conducted noise: input differential, output
differential and input-output.
This last appears as common mode at the
input and the output, and cannot therefore be
removed by filtering at the input or output
alone. The first level of filtering is to connect
a capacitor between input and output returns,
The variation of startup voltage with either
parallel resistor or applied voltage is shown
SD
DC
Less than 0.8V
for Shutdown
If no filtering is required, the inductance of
long supply wiring could also cause a
problem, requiring an input decoupling
capacitor for stability. An electrolytic will
perform well in these situations.
See figure 7 for a recommended
configuration to reduce all three conducted
modes.
The component values and ratings will
depend on the converter rating and voltage,
and the required noise performance. The
input-output filtering is performed by the
common-mode choke on the primary. This
could be placed on the output, but would
then degrade the regulation and produce less
15
2.0
1.5
1.0
17
–VIN
Figure 2: Shutdown with Isolating Diode
Input ripple is a voltage developed across the
internal input decoupling capacitor. It is
therefore measured with a defined supply
source impedance. Although simple series
inductance will provide filtering, on its own it
can degrade the stability. A shunt capacitor is
therefore recommended across the converter
input terminals, so that it is fed from a low
impedance.
2.5
Applied Voltage (V)
e.g. BAT42
DC
to reduce this form of noise. It typically
contains high harmonics of the switching
frequency, which tend to appear as spikes on
surrounding circuits. The voltage rating of this
capacitor must match the required isolation
voltage. (Due to the great variety in isolation
voltage and required noise performance, this
capacitor has not been included within the
converter.)
Shutdown Resistor (MΩ)
SET VOLTAGE
The output voltage is set to 100mV above
nominal, to offset resistive losses and thus
assist with worst case error calculations. This
allowance can be altered with a single fixed
resistor, connected from the trimming pin to
one of the output pins.
17.5
18 18.5 19
Startup Voltage (V)
19.5
10K 0.25W
Greater than 1.5V
for Shutdown
DC
–VIN
Figure 3: Shutdown with Open Collector
Pulldown
7
5
3
17.5
18 18.5 19
Startup Voltage (V)
19.5
20
15
Shutdown Resistor (MΩ)
DC
9
Figure 4: NCX10S24XXX Startup Voltage Vs Startup Pin Resistor/Voltage
Applied Voltage (V)
e.g. BC546
11
1
17
20
2.5
SD
13
2.0
1.5
1.0
32.5 33
33.5 34 34.5 35 35.5
Startup Voltage (V)
36
13
11
9
7
5
3
1
32
33
34
35
Startup Voltage (V)
Figure 5: NCX10S48XXX Startup Voltage Vs Startup Pin Resistor/Voltage
36
NCX10S SERIES
Isolated 10W Single Output DC/DC Converters
APPLICATION NOTES
benefit for a given size, cost, and power loss.
Radiated noise is present in magnetic and
electrostatic forms. Thanks to the small size of
these units, neither form of noise will be
radiated “efficiently”, so will not normally
cause a problem. Any question of this kind
usually better repays attention to conducted
signals.
Optional Open
Collector Transistor
In applications where large transient load
swings are expected, for example 10-60% or
25-75%, the fitting of an external electrolytic
output capacitor is recommended to reduce
voltage over/under shoot. 200µF capacitance
will typically reduce a peak excursion to
350mV settling to within 1% VNOM in 1.2ms.
Additional externally fitted capacitance will
further reduce over/under shoot.
DC
DC
SD
SD
Less than
0.8V for
Shutdown
DC
DC
–VIN
–VIN
PROTECTION
The “absolute maximum” ratings in the
specification define conditions which may
degrade life but will not result in immediate
damage. This section of the application notes
deals with those unavoidable or accidental
occasions when the ratings are exceeded.
The unit will protect itself against a wide
range of abnormal conditions. In others,
where failure is inevitable, the consequent
hazards have been minimised.
If the supply polarity is reversed, the unit is
unable to protect itself. The simple
preventative measure of a series diode would
add unacceptable power loss for the basic
product, but it may be appropriate in some
applications to fit this diode externally.
With no polarity protection, tracks and
components will safely fail to high
impedance, disconnecting the power. A large
fault current will occur in this process.
FUSING
Figure 6: Shutdown with Isolating Diode
100µH
Part Number
Recommended Fuses1
NCX10S24XX
NCX10S48XX
1.6A
1.0A
10µH
DC
2.2µF
1mH
10µH
2.2µF
DC
100µH
10µF, 250Vac Y Rated
Figure 7: Recommended Configuration to Reduce Noise
1 Anti surge T-type fuses are recommended
10µF, 250Vac Y Rated
NCX10S SERIES
Isolated 10W Single Output DC/DC Converters
MECHANICAL DIMENSIONS
18 Pin SMD Package Style
1.75 (44.56)
1.58 (40.03)
18
17
16
15
14
13
12
11
10
1.12 ±0.016
(28.4 ±0.4)
0.82
(20.75)
Detail A
REFERENCE PLANE
0.197
(0.50)
1
2
3
4
5
6
7
8
0.20 (5.0)
0.049±0.008
(1.24±0.2)
x18 Pins
9
0.10±0.004
(2.59±0.1)
±5.00°
0.008(0.2) M
P
S
0.008(0.2) M
0.31
(7.75)
MAX
P
S
0.09±0.001 (2.27±0.25)
S
0.315±0.004
(8.00±0.10)
18 Pins
0.01 (2.51) MAX
DETAIL A
0.010±0.002
(0.25±0.05)
0.004(0.1)
S
Recommended Footprint Details
Pin Connections
0.94
(24.0)
1.17
(29.6)
PIN NCX10SXXXXX NCX10SXXXXXY
1
+VOUT
+VOUT
2
–VOUT
–VOUT
3-7
NC
NC
8
VADJ
VADJ
9-10
NC
NC
11
SD
SD
12-16
NC
NC
17
–VIN
+VIN
18
+VIN
–VIN
Package Weight: 8.3g
0.20 (5.00)
0.14 (3.60)
All pins on a 0.1(2.54) pitch and within
±0.01(0.25) of true position.
1.57 (40.0)
Unless otherwise stated all dimensions in
inches(mm) ±0.01(0.25).
C&D Technologies (NCL) Limited reserve the right to alter or improve the
specification, internal design or manufacturing process at any time, without
notice. Please check with your supplier or visit our web site to ensure that
you have the current and complete specification for your product before use.
© C&D Technologies (NCL) Limited 2003
NDC NCX10S.1
No part of this publication may be copied, transmitted or stored in a
retrieval system or reproduced in any way including, but not limited to,
photography, photocopy, magnetic or other recording means, without prior
written permission from C&D Technologies (NCL) Limited.
Instructions for use are available from www.cdpoweronline.com
C&D Technologies (NCL) Ltd
Tanners Drive, Blakelands North
Milton Keynes MK14 5BU, England
Tel: +44 (0)1908 615232
Fax: +44 (0)1908 617545
email: [email protected]
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C&D Technologies Inc.
3400 E Britannia Drive, Tucson,
Arizona 85706, USA
Tel: +1 (800) 547-2537
Fax: +1 (520) 741-4598
email: [email protected]
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