NCX10S48050Y - C&D Technologies, Inc.

NCX10S SERIES

Isolated 10W Single Output DC/DC Converters

www.cdpoweronline.com

SELECTION GUIDE1

FEATURES

■High Efficiency to 82%

■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.

Order Code V V A mW mW % pF

NCX10S24033 24 3.4 3.1 270 26 78 23

NCX10S24050 24 5.1 2.0 280 25 82 26

NCX10S48033 48 3.4 3.1 500 44 79 29

NCX10S48050 48 5.1 2.0 510 45 82 32

NCX10S24033Y 24 3.4 3.1 270 26 78 23

NCX10S24050Y 24 5.1 2.0 280 25 82 26

NCX10S48033Y 48 3.4 3.1 500 44 79 29

NCX10S48050Y 48 5.1 2.0 510 45 82 32

Parameter Conditions MIN NOM MAX Units

Voltage Range Continuous operation, 24V input types 18 24 36 V

Continuous operation, 48V input types 36 48 75

Nominal

Input Voltage

Output Voltage

Output Current

Power Consumption

at 0% Load

Power Consumption

at Shutdown

Efficiency (MIN)

Isolation

Capacitance

Parameter Conditions MIN TYP MAX Units

Voltage Set Point Error 50% load 1.0 %

Overall Substrate temperature –40 to 110°C

Voltage Error Load 0% - 100% 2.5 %

Input specified range

Temperature Coefficient

of Output Voltage 250 ppm°C

(slope)

Deviation of

Output Voltage

Temperature MIN - MAX

1.0 %

Current Limit Continuous short circuit causes no damage

NCX10S24033 153 % of

Overload 95% of nominal NCX10S24050 170 rated

Output Current output voltage NCX10S48033 148 Output

NCX10S48050 164 Current

Line Regulation Operating voltage range, 50% load 0.1 %

Load Regulation 0% - 100% rated load20.5 %

Ripple rms 1.0 %

Input voltage, 24V input types –0.3V to 40V

Input voltage, 48V input types –0.3V to 80V

Output Voltage –0.3V to regulated voltage

Output trim control –1V to +30V relative to output return

Shutdown control –0.3V to 6V relative to input return

INPUT CHARACTERISTICS1

OUTPUT CHARACTERISTICS1

Parameter Conditions MIN TYP MAX Units

Voltage Trimming At rated load, ±10 %

Range Trim control at either output

Remote Switch Input Not operating -0.3 0 1.5

(voltage relative Operating, open circuit voltage 2.6 5.0 6.1 V

to input negative) VIN MIN to MAX

Start Delay Time from application of valid input

voltage to output being in specification

10 ms

Switching Frequency 360 400 440 kHz

CONTROL CHARACTERISTICS

ABSOLUTE MAXIMUM RATINGS

1Specifications typical at TA=25°C, nominal input voltage and rated output current unless otherwise specified.

2A minimum load of 10% of rating is recommended for typical applications, see application notes.

ENVIRONMENTAL CHARACTERISTICS

APPLICATION NOTES

Parameter Conditions MIN TYP MAX Units

Substrate Temp. Full load –40 125 °C

Storage Absolute MAX internal temperature –40 125 °C

Thermal Protection Operates at substrate temperature 150 °C

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

ISOLATION CHARACTERISTICS

Parameter Conditions MIN TYP MAX Units

Isolation Voltage Flash tested for 1 second 1000 VDC

Resistance VISO=500VDC 1 GΩ

THERMAL PERFORMANCE

-40 10 60 110

Ambient Temperature (°C)

NCX10S24033

Ambient Power (W)

Still Air

100lfm

200lfm

300lfm

400lfm

-40 10 60 110

Ambient Temperature (°C)

NCX10S24050

Ambient Power (W)

Still Air

100lfm

200lfm

300lfm

-40 10 60 110

Ambient Temperature (°C)

NCX10S48033

Ambient Power (W)

Still Air

100lfm

200lfm

-40 10 60 110

Ambient Temperature (°C)

NCX10S48050

Ambient Power (W)

Still Air

100lfm

UL 60950 RECOGNITION (Maximum permissable load in still air)

Part Number -40°C 25°C 70°C 75°C 80°C 85°C 90°C Units

NCX10S24033 10.0 10.0 10.0 9.0 7.9 6.5 5.0

NCX10S24050 10.0 10.0 10.0 10.0 8.9 7.2 5.2 W

NCX10S48033 10.0 10.0 10.0 9.5 8.4 7.1 5.5

NCX10S48050 10.0 10.0 10.0 10.0 10.0 9.6 8.0

NCX10S SERIES

Isolated 10W Single Output DC/DC Converters

+VIN

–VIN

+VOUT

ADJ 100KΩ

Figure 1: 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 10kΩto 100kΩconnected

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, 62kΩwill restrict a 3.3V model

to ±5% adjustment range. The corresponding

values for the 5V model is 56kΩ.

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.

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 1MΩresistor to a

voltage of between 0V and 2.5V.

The variation of startup voltage with either

parallel resistor or applied voltage is shown

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 1kΩmay

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,

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.)

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.

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

2.5

2.0

1.5

1.0

17 17.5 18 18.5 19 19.5 20

Startup Voltage (V)

Applied Voltage (V)

17 17.5 18 18.5 19 19.5 20

Startup Voltage (V)

Shutdown Resistor (MΩ)

NCX10S SERIES

Isolated 10W Single Output DC/DC Converters

Figure 2: Shutdown with Isolating Diode

Figure 3: Shutdown with Open Collector

Pulldown

Figure 4: NCX10S24XXX Startup Voltage Vs Startup Pin Resistor/Voltage

2.5

2.0

1.5

1.0

32.5 33 33.5 34 34.5 35 35.5 36

Startup Voltage (V)

Applied Voltage (V)

32 33 34 35 36

Startup Voltage (V)

Shutdown Resistor (MΩ)

Figure 5: NCX10S48XXX Startup Voltage Vs Startup Pin Resistor/Voltage

APPLICATION NOTES

–VIN

e.g. BAT42

Less than 0.8V

for Shutdown

–VIN

e.g. BC546

Greater than1.5V

for Shutdown

10K 0.25W

1 Anti surge T-type fuses are recommended

FUSING

Part Number Recommended Fuses1

NCX10S24XX 1.6A

NCX10S48XX 1.0A

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.

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.

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.

NCX10S SERIES

Isolated 10W Single Output DC/DC Converters

APPLICATION NOTES

Figure 6: Shutdown with Isolating Diode

–VIN

2.2µF 2.2µF

100µH 10µH

10µH

10µF, 250Vac Y Rated

100µH

1mH

Less than

0.8V for

Shutdown

Optional Open

Collector Transistor DC

–VIN

Figure 7: Recommended Configuration to Reduce Noise

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: info@cdtechno-ncl.com

www.cdpoweronline.com

C&D Technologies Inc.

3400 E Britannia Drive, Tucson,

Arizona 85706, USA

Tel: +1 (800) 547-2537

Fax: +1 (520) 741-4598

email: pedmktg@cdtechno.com

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.

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

MECHANICAL DIMENSIONS

NCX10S SERIES

Isolated 10W Single Output DC/DC Converters

0.20 (5.0)

0.01 (2.51) MAX

0.20 (5.00)

1.57 (40.0)

0.14 (3.60)

0.10±0.004

(2.59±0.1)

1.58 (40.03)

1.12 ±0.016

(28.4 ±0.4)

0.82

(20.75)

1.17

(29.6)

0.94

(24.0)

0.31

(7.75)

MAX

0.008(0.2) M

0.004(0.1)

18 Pins

0.09±0.001 (2.27±0.25)

DETAIL A

0.010±0.002

(0.25±0.05)

REFERENCE PLANE

0.049±0.008

(1.24±0.2)

x18 Pins

0.197

(0.50) ±5.00°

0.008(0.2) M

Detail A

Recommended Footprint Details Pin Connections

18 17 16 15 14 13 12 11 10

23456789

All pins on a 0.1(2.54) pitch and within

±0.01(0.25) of true position.

Unless otherwise stated all dimensions in

inches(mm) ±0.01(0.25).

PIN NCX10SXXXXX NCX10SXXXXXY

1+V

OUT +VOUT

2–V

OUT –VOUT

3-7 NC NC

ADJ VADJ

9-10 NC NC

11 SD SD

12-16 NC NC

17 –VIN +VIN

18 +VIN –VIN

Package Weight: 8.3g

1.75 (44.56)

18 Pin SMD Package Style

0.315±0.004

(8.00±0.10)