Delta Electronics NC15 User Manual

Delphi NC15 Series Non-Isolated Point of Load

FEATURES

 High Efficiency:

91% @ 12Vin, 5V/15A out

 Size: 30.5x27.9x11.4mm

(1.20”×1.10”×0.45”) -- Vertical

30.5x27.9x12.9mm

(1.20”×1.10”×0.51”) -- Horizontal

 Voltage and resistor-based trim

 No minimum load required

 Output voltage programmable from

0.9Vdc to 5.0Vdc via external resistors

 Fixed frequency operation

 Input UVLO, output OCP, SCP

 Power good output signal

 Remote ON/OFF (default: Positive)

 ISO 9000, TL 9000, ISO 14001 certified

manufacturing facility

 UL/cUL 60950-1 (US & Canada)

Recognized, and TUV (EN60950-1)

Certified

 CE mark meets 73/23/EEC and 93/68/EEC

directives

DC/DC Power Modules: 12Vin, 0.9V-5.0Vout, 15A

The Delphi NC15 Series, 12V input, single output, non-isolated point of

load DC/DC converters are the latest offering from a world leader in

power systems technology and manufacturing ― Delta Electronics, Inc.

The NC15 series operates from a 12V nominal input, provides up to 15A

of power in a vertical or horizontal mounted through-hole package and

the output can be resistor- or voltage-trimmed from 0.9Vdc to 5.0Vdc. It

provides a very cost effective point of load solution. With creative design

technology and optimization of component placement, these converters

possess outstanding electrical and thermal performance, as well as

extremely high reliability under highly stressful operating conditions.

OPTIONS

 Vertical or horizontal versions

 Negative ON/OFF logic

APPLICATIONS

 DataCom

 Distributed power architectures

 Servers and workstations

 LAN / WAN applications

 Data processing applications

DATASHEET
DS_NC12S15A_01102008

TECHNICAL SPECIFICATIONS

(Ambient Temperature=25°C, minimum airflow=200LFM, nominal Vin=12Vdc unless otherwise specified.)

PARAMET E R NOTES and CONDITIONS NC12S0A0V/H15

Min. Typ. Max. Units

ABSOLUTE MAXIMUM RATINGS

Input Voltage 14 Vdc
Operating Temperature (Vertical) With appropriate air flow and derating, see Figs 33 0 130 °C
Operating Temperature (Horizontal) With appropriate air flow and derating, see Figs 39 0 125 °C
Storage Temperature -40 125 °C
Input/Output Isolation Voltage Non-isolated NA V

INPUT CHARACTERISTICS

Operating Input Voltage 10.2 12.0 13.8 V
Input Under-Voltage Lockout

Turn-On Voltage Threshold 9.0 V
Turn-Off Voltage Threshold 7.5 V

Lockout Hysteresis Voltage 1.5 V
Maximum Input Current 100% Load, 10.2Vin, 5.0Vout 8.1 A
No-Load Input Current Vin=12V, Vout=0.9V 65 mA
Off Converter Input Current Remote OFF 9 mA
Input Reflected-Ripple Current Refer to Figure 31. 150 mA
Input Ripple Rejection 120Hz 45 dB

OUTPUT CHARACTERISTICS

Output Voltage Adjustment Range 0.9 5.0 V
Output Voltage Set Point With a 1.0% trim resistor -2.5 +2.5 %
Output Voltage Regulation

Over Load Io=Io_min to Io_max -1.0 +1.0 %

Over Line Vin=Vin_min to Vin_max -0.2 +0.2 %
Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth

Peak-to-Peak Full Load, 100nF ceramic, 10µF tantalum 50 mV

RMS Full Load, 100nF ceramic, 10µF tantalum 20 mV
Output Current Range 0 15 A
Output Voltage Over-shoot at Start-up Vin=12V, Turn ON 1 %
Output Voltage Under-shoot at Power-Off Vin=12V, Turn OFF 100 mV
Output DC Current-Limit Inception Hiccup mode 16 A
Output Short-Circuit Current Hiccup mode

DYNAMIC CHARACTERISTICS

Output Dynamic Load Response 12Vin, 100nF ceramic, 10µF tantalum load cap, 10A/µs

Positive Step Change in Output Current 50% Io_max to 75% Io_max 100 mV

Negative Step Change in Output Current 75% Io_max to 50% Io_max 100 mV

Settling Time Settling to be within regulation band (Vo +/- 2.5%) 200 µs
Turn-On Transient

Start-Up Time, from On/Off Control From Enable high to 10% of Vo 10 ms

Start-Up Time, from input power From Vin=12V to 10% of Vo 10 ms
Minimum Output Capacitance Ex: OSCON 6.3V/680µF (ESR 13 mΩ max.) 680 µF
Maximum Output Startup Capacive Load Full Load 6800 µF
Minimum Input Capacitance Ex: OSCON 16V/270µF (ESR 18 mΩ max.) 270 µF

EFFICIENCY

Vo=0.9V Vin=12V, Io=15A 75 %
Vo=1.2V Vin=12V, Io=15A 79 %
Vo=1.5V Vin=12V, Io=15A 81 %
Vo=1.8V Vin=12V, Io=15A 84 %
Vo=2.5V Vin=12V, Io=15A 87 %
Vo=3.3V Vin=12V, Io=15A 89 %
Vo=5.0V Vin=12V, Io=15A 91 %

FEATURE CHARACTERISTICS

Switching Frequency fixed 300 KHz
ON/OFF Control Positive logic (internally pulled high)
Logic High Module On (or leave the pin open) 2.4 5.5 V
Logic Low Module Off 0 0.8 V

GENERAL SPECIFICATIONS

MTBF Telcordia SR-332 Issue1 Method1 Case3 at 50°C 2.1 M hours
Weight 16.5 grams

NC12S15A_01102008

2

ELECTRICAL CHARACTERISTICS CURVES

90

80

70

60

50

40

30

Efficiency (%)

20

10

0

01234567 89101112131415

10.2 12 13.8

Output Current (A)

Figure 1: Converter efficiency vs. output current Figure 2: Converter efficiency vs. output current

(0.9V output voltage) (1.2V output voltage)

90

80

70

60

50

40

30

Efficiency (%)

20

10

0

01234567 89101112131415

10.2 12 13.8

Output Current (A)

100

90

80

70

60

50

40

Efficiency (%)

30

20

10

0

0123456789101112131415

10.2 12 13.8

Output Current (A)

Figure 3: Converter efficiency vs. output current

(1.8V output voltage)

100

90

80

70

60

50

40

Efficiency (%)

30

20

10

0

0123456789101112131415

10.2 12 13.8

Output Current (A)

Figure 5: Converter efficiency vs. output current

(3.3V output voltage)

100

90

80

70

60

50

40

Efficiency (%)

30

20

10

0

0123456789101112131415

10.2 12 13.8

Output Current (A)

Figure 4: Converter efficiency vs. output current

(2.5V output voltage)

100

90

80

70

60

50

40

Efficiency (%)

30

20

10

0

0123456789101112131415

10.2 12 13.8

Output Current (A)

Figure 6: Converter efficiency vs. output current

(5.0V output voltage)

NC12S15A_01102008

3

ELECTRICAL CHARACTERISTICS CURVES

Figure 7: Output ripple & noise at 12Vin, 0.9V/15A out

Figure 9: Output ripple & noise at 12Vin, 1.8V/15A out

Figure 8: Output ripple & noise at 12Vin, 1.2V/15A out

Figure 10: Output ripple & noise at 12Vin, 2.5V/15A out

Figure 11: Output ripple & noise at 12Vin, 3.3V/15A out

NC12S15A_01102008

Figure 12: Output ripple & noise at 12Vin, 5.0V/15A out

4

ELECTRICAL CHARACTERISTICS CURVES

Figure 13: Turn on delay time at 12Vin, 0.9V/15A out

Ch2:Vin Ch3:Vout Ch4:PWRGD

Figure 15: Turn on delay time at 12Vin, 2.5V/15A out

Ch2:Vin Ch3:Vout Ch4:PWRGD

Figure 14: Turn on delay time Remote On/Off, 0.9V/15A out

Ch2:ENABLE Ch3:Vout Ch4:PWRGD

Figure 16: Turn on delay time at Remote On/Off, 2.5V/15A out

Ch2:ENABLE Ch3:Vout Ch4:PWRGD

Figure 17: Turn on delay time at 12Vin, 5.0V/15A out

Ch2:Vin Ch3:Vout Ch4:PWRGD

NC12S15A_01102008

Figure 18: Turn on delay time at Remote On/Off, 5.0V/15A out

Ch2:ENABLE Ch3:Vout Ch4:PWRGD

5

ELECTRICAL CHARACTERISTICS CURVES

Figure 19: Typical transient response to step load change at

10A/μS from 50% to 75% and 75% to 50% of Io_max at
12Vin, 0.9V out

Figure 21: Typical transient response to step load change at

10A/μS from 50% to 75% and 75% to 50% of Io_max at

12Vin, 2.5V out

Figure 20: Typical transient response to step load change at

10A/μS from 50% to 75% and 75% to 50% of Io_max at

12Vin, 1.2V out

Figure 22: Typical transient response to step load change at

10A/μS from 50% to 75% and 75% to 50% of Io_max at

12Vin, 5.0V out

NC12S15A_01102008

6

DESIGN CONSIDERATIONS

f

t

r

r

The NC15 is a single phase and voltage mode controlled

Buck topology. Block diagram of the converter is shown in

Figure 23. The output can be trimmed in the range o

0.9Vdc to 5.0Vdc by a resistor from Trim pin to Ground.

The converter can be turned ON/OFF by remote control.

Positive on/off (ENABLE pin) logic implies that the

converter DC output is enabled when this signal is driven

high (greater than 2.4V) or floating and

disabled when the

signal is driven low (below 0.8V). Negative on/off logic is

optional and could also be ordered.

The converter provides an open collector signal called

Power Good. The power good signal is pulled low when

output is not within ±10% of Vout or Enable is OFF.

The converter can protect itself by entering hiccup mode

against over current and short circuit condition. Also, the

converter will shut down when an over voltage protection

is detected.

FEATURES DESCRIPTIONS

ENABLE (On/Off)

The ENABLE (on/off) input allows external circuitry to pu
the NC converter into a low power dissipation (sleep)
mode. Positive (active-high) ENABLE is available as
standard.

Positive ENABLE (active-high) units of the NC series are
turned on if the ENABLE pin is high or floating. Pulling the
pin low will turn off the unit. With the active high function,
the output is guaranteed to turn on if the ENABLE pin is
driven above 2.4V. The output will turn off if the ENABLE
pin voltage is pulled below .8V.

The ENABLE input can be driven in a variety of ways as
shown in Figures 24, 25 and 26. If the ENABLE signal
comes from the primary side of the circuit, the ENABLE
can be driven through either a bipolar signal transisto
(Figure 24) or a logic gate (Figure 25). If the enable signal
comes from the secondary side, then an opto-coupler o
other isolation devices must be used to bring the signal
across the voltage isolation (please see Figure 26).

Figure 23: Block Diagram

Safety Considerations

It is recommended that the user to provide a very

fast-acting type fuse in the input line for safety. The output

voltage set-point and the output current in the application

could define the current rating of the fuse.

Figure 24: Enable Input drive circuit for NC series

5V

Figure 25: Enable input drive circuit using logic gate.

NC6A/15A/20A

Vin

Ground

NC6A/15A/20A

Vin

Ground

NC6A/15A/20A

Vin

Enable

Vout

Trim Enable

Ground

Vout

TrimEnable

Ground

Vout

Trim

NC12S15A_01102008

Ground

Figure 26: Enable input drive circuit example with isolation.

Ground

7

FEATURES DESCRIPTIONS (CON.)

t

t

A

T

−

−

Input Under-Voltage Lockout

The input under-voltage lockout prevents the converter

from being damaged while operating when the inpu

voltage is too low. The lockout occurs between 7.0V to

8.0V.

Over-Current and Short-Circuit Protection

The NC series modules have non-latching over-current

and short-circuit protection circuitry. When over curren

condition occurs, the module goes into the non-latching

hiccup mode. When the over-current condition is

removed, the module will resume normal operation.

n over current condition is detected by measuring the
voltage drop across the high-side MOSFET. The voltage
drop across the MOSFET is also a function of the
MOSFET’s Rds(on). Rds(on) is affected by temperature,
therefore ambient temperature will affect the current limit
inception point. Please see the electrical characteristics
for details of the OCP function.

The detection of the Rds(on) of the high side MOSFE
also acts as an over temperature protection since high
temperature will cause the Rds(on) of the MOSFET to
increase, eventually triggering over-current protection.

Output Voltage Programming

The output voltage of the NC series is trimmable by
connecting an external resistor between the trim pin and
output ground as shown Figure 27 and the typical trim
resistor values are shown in Figure 28. The output can
also be set by an external voltage connected to trim pin as
shown in Figure 29.

NC6A/15A/20A

Vin

Enable

Ground

Figure 27: Trimming Output Voltage

NC12S15A_01102008

Vout

Trim

Ground

Rs

The NC06/NC15/NC20 module has a trim range of 0.9V
to 5.0V. The trim resistor equation for the NC6A/NC15A/
NC20A is :

1170

)(

Rs

=Ω

Vout

Vout is the output voltage setpoint
Rs is the resistance between Trim and Ground
Rs values should not be less than 280Ω

9.0

−

Output Voltage Rs (Ω)

OPEN +0.9 V

3.92K +1.2 V

+1.5 V 1.96K
+1.8 V 1.3K
+2.5 V 732
+3.3 V 487

287 +5.0 V

Figure 28: Typical trim resistor values

NC6A/15A/20A

Vin

Enable

Ground

Figure 29: Output voltage trim with voltage source

1.3K

Vout

Trim

Ground

Rs

Rt

Vt

To use voltage trim, the trim equation for the
NC6A/NC15A/ NC20A is (please refer to Fig. 29) :

=Ω

kRt

)(

VtRs

VoutRs

Vout is the desired output voltage
Vt is the external trim voltage
Rs is the resistance between Trim and Ground (in KΩ)
Rt is the resistor to be defined with the trim voltage (in KΩ)

)17.13.1(

)9.0(17.1

−−

Below is an example about using this voltage trim
equation :

Example：

If Vt = 1.25V, desired Vout = 2.5V and Rs = 0.715KΩ

=Ω K

KRt 51.12

)(

VtRs

VoutRs

)17.13.1(

)9.0(17.1

−−

Ω=

8

FEATURES DESCRIPTIONS (CON.)

r

f

r

t

r

n

t

Power Good

The converter provides an open collector signal called
Power Good. This output pin uses positive logic and is

open collector. This power good output is able to sink
5mA and set high when the output is within ±10% o
output set point.

The power good signal is pulled low when output is not
within ±10% of Vout or Enable is OFF.

Current Sink Capability

The NC series converters are able to sink current as well
as function as a current source. It is able to sink the full
output current at any output voltage up to and including

2.5V. This feature allows the NC series fit into any
voltage termination application.

Voltage Margining Adjustment

Output voltage margin adjusting can be implemented in
the NC modules by connecting a resistor, R
the Trim pin to the Ground for for margining
voltage. Also, the output voltage can be adjusted lowe
by connecting a resistor, Rmargin-down, from the Trim pin to
the voltage source Vt. Figure 30 shows the circuit
configuration for output voltage margining adjustment.

margin-up, from

up the output

Output Capacitance

There is no output capacitor on the NC series modules.
Hence, an external output capacitor is required for stable
operation. For NC15 modules, an external 6.3V/680μF

low ESR capacitor (for example, OSCON) is required fo
stable operation.

It is important to places these low ESR capacitors as
close to the load as possible in order to get improved
dynamic response and better voltage regulation,
especially when the load current is large. Several of these
low ESR capacitors could be used together to furthe
lower the ESR.

Please refer to individual datasheet for the maximum
allowed start-up load capacitance for each NC series as i
is varied between series.

Reflected Ripple Current and Output Ripple and
Noise Measurement

The measurement set-up outlined in Figure 31 has been
used for both input reflected/ terminal ripple current and
output voltage ripple and noise measurements on NC
series converters.

Vt

NC6A/15A/20A

Vin

Enable

Ground

Vout

Trim

Rs

Ground

Rmargin-dow

Rmargin-up

Figure 30: Circuit configuration for output voltage margining

Paralleling

NC06/NC15/NC20 converters do not have built-in curren
sharing (paralleling) ability. Hence, paralleling of multiple
NC06/NC15/NC20 converters is not recommended.

NC12S15A_01102008

Cs=270μF*1, Ltest=1.4μH, Cin=270μF*1, Cout=680μF *1

Figure 31: Input reflected ripple/ capacitor ripple current and

output voltage ripple and noise measurement setup for NC15

9

THERMAL CONSIDERATION

Thermal management is an important part of the
system design. To ensure proper, reliable operation,
sufficient cooling of the power module is needed over
the entire temperature range of the module.
Convection cooling is usually the dominant mode of
heat transfer.

Hence, the choice of equipment to characterize the
thermal performance of the power module is a wind
tunnel.

Thermal Testing Setup

Delta’s DC/DC power modules are characterized in
heated vertical wind tunnels that simulate the thermal
environments encountered in most electronics
equipment. This type of equipment commonly uses
vertically mounted circuit cards in cabinet racks in
which the power modules are mounted.

The following figure shows the wind tunnel
characterization setup. The power module is mounted
on a test PWB and is vertically positioned within the
wind tunnel. The space between the neighboring PWB
and the top of the power module is constantly kept at

6.35mm (0.25’’).

Thermal Derating

Heat can be removed by increasing airflow over the
module. To enhance system reliability, the power
module should always be operated below the
maximum operating temperature. If the temperature
exceeds the maximum module temperature, reliability
of the unit may be affected.

NC12S15A_01102008

10

THERMAL CURVES (NC12S0A0V15)

A

FAC IN G P WB

PWB

MODULE

AIR VELOCITY

AND AMBIENT

TEMPERATURE

MEASURED BELOW

THE MODULE

IR FLOW

50.8 (2.0”)

17.5 (0.69”)
35 (1.38”)

Note: Wind Tunnel Test Setup Figure Dimensions are in

millimeters and (Inches)

Figure 32: Wind tunnel test setup

NC12S0A0V15 (Standard) Output Current vs. Ambient Temperature and Air Velocity

Output Current(A)

15

12

Natural

Convection

9

100LFM

200LFM

6

300LFM

400LFM

3

0

25 30 35 40 45 50 55 60 65 70 75 80 85

@ Vout = 3.3V (Either Orientation)

Ambient Temperature (℃)

Figure 35: Output current vs. ambient temperature and air

velocity@ Vout=3.3V(Either Orientation)

Output Current(A)

15

12

9

6

NC12S0A0V15 (Standard) Output Current vs. Ambient Temperature and Air Velocity

Natural

Convection

100LFM

200LFM

300LFM

@ Vout = 1.8V (Either Orientation)

Figure 33: Temperature measurement location

* The allowed maximum hot spot temperature is defined at 130

NC12S0A0V15 (Standard) Output Current vs. Ambient Temperature and Air Velocity

Output Current(A)

15

12

Natural

Convection

9

100LFM

200LFM

6

300LFM

400LFM

3

0

25 30 35 40 45 50 55 60 65 70 75 80 85

@ Vout = 5V (Either Orientation)

Ambient Temperature (℃)

Figure 34: Output current vs. ambient temperature and air
velocity@Vout=5V(Either Orientation)

NC12S15A_01102008

℃

3

0

25 30 35 40 45 50 55 60 65 70 75 80 85

Ambient Temperature (℃)

Figure 36: Output current vs. ambient temperature and air
velocity@ Vout=1.8V(Either Orientation)

NC12S0A0V15 (Standard) Output Current vs. Ambient Temperature and Air Velocity

Output Current(A)

15

12

Natural

Convection

9

100LFM

200LFM

6

300LFM

3

0

25 30 35 40 45 50 55 60 65 70 75 80 85

@ Vout = 0.9V (Either Orientation)

Ambient Temperature (℃)

Figure 37: Output current vs. ambient temperature and air
velocity@ Vout=0.9V(Either Orientation)

11

THERMAL CURVES (NC12S0A0H15)

A

FACING PWB

PWB

MODULE

AIR VELOCITY
AND AMBIENT

TEMPERATURE

MEASURED BELOW

THE MODULE

IR FLOW

50.8 (2.0”)

9.5 (0.37”)
19 (0.75”)

Note: Wind Tunnel Test Setup Figure Dimensions are in

millimeters and (Inches)

Figure 38: Wind tunnel test setup

NC12S0A0H15 (Standard) Output Current vs. Ambient Temperature and Air Velocity

Output Current(A)

15

12

9

6

3

0

25 35 45 55 65 75 85

@ Vout =3.3V (Either Orientation)

Natural

Convection

100LFM

200LFM

300LFM

Ambient Temperature (℃)

Figure 41: Output current vs. ambient temperature and air

velocity@ Vout=3.3V(Either Orientation)

Output Current(A)

15

12

9

6

NC12S0A0H15 (Standard) Output Current vs. Ambient Temperature and Air Velocity

@ Vout =1.8V (Either Orientation)

Natural

Convection

100LFM

200LFM

Figure 39: Temperature measurement location

* The allowed maximum hot spot temperature is defined at 125

NC12S0A0H15 (Standard) Output Current vs. Ambient Temperature and Air Velocity

Output Current(A)

15

12

9

6

3

0

25 35 45 55 65 75 85

@ Vout =5V (Either Orientation)

Natural

Convection

100LFM

200LFM

300LFM

400LFM

Ambient Temperature (℃)

Figure 40: Output current vs. ambient temperature and air

velocity @Vout=5V(Either Orientation)

NC12S15A_01102008

℃

3

0

25 35 45 55 65 75 85

Ambient Temperature (℃)

Figure 42: Output current vs. ambient temperature and air
velocity@ Vout=1.8V(Either Orientation)

NC12S0A0H15 (Standard) Output Current vs. Ambient Temperature and Air Velocity

Output Current(A)

15

12

9

6

3

0

25 35 45 55 65 75 85

@ Vout =0.9V (Either Orientation)

Natural

Convection

100LFM

200LFM

Ambient Temperature (℃)

Figure 43: Output current vs. ambient temperature and air
velocity@ Vout=0.9V(Either Orientation)

12

MECHANICAL DRAWING

VERTICAL HORIZONTAL

NC12S15A_01102008

13

PART NUMBERING SYSTEM

NC 12 S 0A0 V 15 P N F A

Product

Series

NC-

Non-isolated

Converter

Input

Voltage

12-

10.2~13.8V

Number of

outputs

S- Single

output

Output

Voltage

0A0-

programmable

Mounting

H- Horizontal

V- Vertical

Output

Current

15 - 15A P- Positive

ON/OFF

Logic

N- Negative

Pin

Length

R- 0.118”

N- 0.14”

Option

Code

F- RoHS 6/6

(Lead Free)

A- Standard

function.

MODEL LIST

Model Name Packaging Input Voltage Output Voltage Output Current

NC12S0A0V15PNFA Vertical 10.2 ~ 13.8Vdc 0.9 V ~ 5.0Vdc 15A 91% (5.0V)

NC12S0A0H15PNFA Horizontal 10.2 ~ 13.8Vdc 0.9 V ~ 5.0Vdc 15A 91% (5.0V)

Efficiency

12Vin @ 100% load

CONTACT:

USA:

Telephone:
East Coast: [phone]
West Coast: [phone]
Fax: [phone]
Email:

[e-mail]

www.delta.com.tw/dcdc

Europe:

Telephone: [phone]
Fax: [phone]
Email:

[e-mail]

Asia & the rest of world:

Telephone: [phone] x6220
Fax: [phone]
Email:

[e-mail]

WARRANTY

Delta offers a two (2) year limited warranty. Complete warranty information is listed on our web site or is available upon
request from Delta.

Information furnished by Delta is believed to be accurate and reliable. However, no responsibility is assumed by Delta
for its use, nor for any infringements of patents or other rights of third parties, which may result from its use. No license
is granted by implication or otherwise under any patent or patent rights of Delta. Delta reserves the right to revise these
specifications at any time, without notice

NC12S15A_01102008

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