Delta Electronics Delphi ND Series User manual

PRELIMINARY DATASHEET
DS_ND12S50A_07172008
FEATURES
High efficiency:
92.5% @ 12Vin, 3.3V/50A out
ySize: 61.0x31.8x10.2mm
(2.40”×1.25”×0.40”)
Voltage and resistor-based trim
No minimum load required
Output voltage programmable from
0.9Vdc to 3.63Vdc via external resistors
Fixed frequency operation
Single-in line package (SIP)
Input UVLO, output OCP, OTP, SCP
Remote ON/OFF (Positive)
Power good output signal (open collector)
Output voltage sense
ISO 9001, TL 9000, ISO 14001, QS9000,
OHSAS18001 certified manufacturing facility
UL/cUL 60950-1 (US & Canada), TUV
(EN60950-1) - pending
APPLICATIONS
DataCom
Distributed power architectures
Servers and workstations
LAN / WAN applications
Data processing applications
OPTION
Negative on/off logic
Current sharing
Delphi ND Series Non-Isolated Point of Load
DC/DC Power Modules: 12Vin, 0.9V~3.63Vout,
50Aout
The Delphi ND Series, 12V input, single output, non-isolated point of
load (POL) DC/DC converters are the latest offering from a world leader
in power systems technology and manufacturing — Delta Electronics,
Inc. The ND/NE product family is the second generation, non-isolated
point-of-load DC/DC power modules for the DataCom / Networking / IT
Applications and it will help to cut the module size by 35% to 50%
compared to the first generation NC series POL modules. The ND/NE
product family provides 6A to 60A of output current in a vertically or
horizontally mounted through-hole package and the output can be
resistor trimmed from 0.9Vdc to 3.63Vdc. It provides a very cost
effective, high efficiency, and high density 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.

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TECHNICAL SPECIFICATIONS
(Ambient Temperature=25°C, minimum airflow=200LFM, nominal Vin=12Vdc unless otherwise specified.)
PARAMETER NOTES and CONDITIONS ND12S0A0V50 (Standard)
Min. Typ. Max. Units
ABSOLUTE MAXIMUM RATINGS
Input Voltage -0.3 13.8 Vdc
Operating Temperature Refer to Figure 32 for the measuring point 0 124 °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 8.5 9.0 9.5 V
Turn-Off Voltage Threshold 7.1 7.6 8.1 V
Lockout Hysteresis Voltage 1.4 V
Maximum Input Current 100% Load, 10.2Vin, 3.3Vout 24 A
No-Load Input Current Vin=12V, Vout=3.3V 250 mA
Off Converter Input Current Remote OFF 15 30 mA
Inrush Transient Vin=10.2~13.8V, Io=Min to Max Load 1.00 A2S
Input Reflected-Ripple Current Refer to Figure 31. 20 mA
Input Ripple Rejection 120Hz 60 dB
OUTPUT CHARACTERISTICS
Output Voltage Adjustment Range 0.9 3.63 V
Output Voltage Set Point With a 1.0% trim resistor -2 +2 %
Output Voltage Regulation
Over Load Io=Io_min to Io_max -1 +1 %
Over Line Vin=Vin_min to Vin_max -0.2 +0.2 %
Total output range Over load, line, temperature regulation and set point -3 +3 %
Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth
Peak-to-Peak Full Load, 1uF ceramic, 10uF Tan cap and 4*680uF OSCON 25 50 mV
RMS Full Load, 1uF ceramic, 10uF Tan cap and 4*680uF OSCON 5 15 mV
Output Current Range 0 50 A
Output Voltage Over-shoot at Start-up Vin=12V, Turn ON 2 %
Output Voltage Under-shoot at Power-Off Vin=12V, Turn OFF 100 mV
Output DC Current-Limit Inception Hiccup mode 110 200 %Iomax
DYNAMIC CHARACTERISTICS
Output Dynamic Load Response 12Vin, 1uF ceramic, 10uF Tan cap and 4*680uF OSCON
Positive Step Change in Output Current 25A to 37.5A, 10A/uS 75 mV
Negative Step Change in Output Current 37.5A to 25A, 10A/uS 75 mV
Settling Time Settling to be within regulation band (to 10% Vo deviation) 50 µs
Turn-On Transient
Start-Up Time, from On/Off Control From Enable high to 90% of Vo 10 ms
Start-Up Time, from input power From Vin=12V to 90% of Vo 10 ms
Minimum Output Capacitance Ex: One OSCON 6.3V/680uF (ESR=13mmax) 680 µF
Maximum Output Startup Capacive Load Full Load (ESR≧1m) 3000 µF
Minimum Input Capacitance 0 µF
EFFICIENCY
Vo=0.9V Vin=12V, Io=50A 81 %
Vo=1.2V Vin=12V, Io=50A 84.5 %
Vo=1.5V Vin=12V, Io=50A 87 %
Vo=1.8V Vin=12V, Io=50A 88.5 %
Vo=2.5V Vin=12V, Io=50A 91 %
Vo=3.3V Vin=12V, Io=50A 92.5 %
Vo=3.63V Vin=12V, Io=50A 92.8 %
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 Vinmax V
Logic Low Module Off -0.2 0.8 V
Remote Sense Range 0.5 V
GENERAL SPECIFICATIONS
Calculated MTBF Telcordia SR-332 Issue1 Method1 Case3 at 50°C TBD Mhours
Weight 34.2 grams
Over-Temperature Shutdown Refer to Figure 32 for the measuring point 134 °C

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ELECTRICAL CHARACTERISTICS CURVES
70
75
80
85
90
95
5.01 10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (A)
EFFICIENCY (%)
10.2 12.0 13.8
70
75
80
85
90
95
5.01 10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (A)
EFFICIENCY (%)
10.2 12.0 13.8
Figure 1: Converter efficiency vs. output current
(0.9V output voltage)
Figure 2: Converter efficiency vs. output current
(1.2V output voltage)
70
75
80
85
90
95
5.01 10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (A)
EFFICIENCY (%)
10.2 12.0 13.8
70
75
80
85
90
95
100
5.01 10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (A)
EFFICIENCY (%)
10.2 12.0 13.8
Figure 3: Converter efficiency vs. output current
(1.5V output voltage)
Figure 4: Converter efficiency vs. output current
(1.8V output voltage)
70
75
80
85
90
95
100
5.01 10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (A)
EFFICIENCY (%)
10.2 12.0 13.8
70
75
80
85
90
95
100
5.01 10 15 20 25 30 35 40 45 50
OUTPUT CURRENT (A)
EFFICIENCY (%)
10.2 12.0 13.8
Figure 5: Converter efficiency vs. output current
(2.5V output voltage)
Figure 6: Converter efficiency vs. output current
(3.3V output voltage)

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ELECTRICAL CHARACTERISTICS CURVES (CON.)
Figure 7: Output ripple & noise at 12Vin, 0.9V/50A out Figure 8: Output ripple & noise at 12Vin, 1.2V/50A out
Figure 9: Output ripple & noise at 12Vin, 1.5V/50A out Figure 10: Output ripple & noise at 12Vin, 1.8V/50A out
Figure 11: Output ripple & noise at 12Vin, 2.5V/50A out Figure 12: Output ripple & noise at 12Vin, 3.3V/50A out

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ELECTRICAL CHARACTERISTICS CURVES (CON.)
Figure 13: Turn on delay time at 12Vin, 0.9V/50A out
Ch1: Vout Ch4: Vin Figure 14: Turn on delay time Remote On/Off, 0.9V/50A out Ch1: Vout Ch4: Enable
Figure 15: Turn on delay time at 12Vin, 3.3V/50A out
Ch1: Vout Ch4: Vin Figure 16: Turn on delay time at Remote On/Off, 3.3V/50A out Ch1: Vout Ch4: Enable
Figure 17: 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 18: 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

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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, 1.5V
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, 1.8V
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 22: Typical transient response to step load change at
10A/μS from 50%to 75% and 75% to 50 of Io, max at 12Vin, 3.3V
out

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DESIGN CONSIDERATIONS
The ND 50A uses two phase and voltage mode controlled
buck topology. The output can be trimmed in the range of
0.9Vdc to 3.63Vdc with a resistor from Trim pin to Ground.
A remote sense function is provided and it is able to
compensate for a drop from the output of converter to
point of load.
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 the 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.
The converter provides an open collector Power Good
signal. 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.
The converter has an over temperature protection which
can protect itself by shutting down for an over
temperature event. There is a thermal hysteresis of
typically 20°C
Safety Considerations
It is recommended that the user to provide a fuse with
TBD in the input line for safety. The output voltage
set-point and the output current in the application could
define the amperage rating of the fuse.
FEATURES DESCRIPTIONS
ENABLE (On/Off)
The ENABLE (on/off) input allows external circuitry to put
the ND converter into a low power dissipation (sleep)
mode. Positive ENABLE is available as standard.
Positive ENABLE units of the ND 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 0.8V.
The ENABLE input can be driven in a variety of ways as
shown in Figures 23 and 24. If the ENABLE signal comes
from the primary side of the circuit, the ENABLE can be
driven through either a bipolar signal transistor (Figure
23). If the enable signal comes from the secondary side,
then an opto-coupler or other isolation devices must be
used to bring the signal across the voltage isolation
(please see Figure 24).
Figure 23: Enable Input drive circuit for ND series
Figure 24: Enable input drive circuit example with isolation.

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FEATURES DESCRIPTIONS (CON.)
Input Under-Voltage Lockout
The input under-voltage lockout prevents the converter
from being damaged while operating when the input
voltage is too low. The lockout occurs between 7.6V to
9.0V.
Over-Current and Short-Circuit Protection
The ND series modules have non-latching over-current
and short-circuit protection circuitry. When over current
condition occurs, the module goes into the non-latching
hiccup mode. When the over-current condition is
removed, the module will resume normal operation.
An over current condition is detected by measuring the
voltage drop across the MOSFETs. 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.
The detection of the Rds(on) of MOSFETs also acts as
an over temperature protection since high temperature
will cause the Rds(on) of the MOSFETs to increase,
eventually triggering over-current protection.
Remote sense
The ND50 provide Vo remote sensing to achieve proper
regulation at the load points and reduce effects of
distribution losses on output line. In the event of an open
remote sense line, the module shall maintain local sense
regulation through an internal resistor. The module shall
correct for a total of 0.5V of loss. The remote sense
connects as shown in Figures 25.
Figure 25: circuit configuration for remote sense
Over Temperature Protection (OTP)
To provide additional over-temperature protection in a
fault condition, the unit is equipped with a non-latching
thermal shutdown circuit. The shutdown circuit engages
when the temperature of monitored component exceeds
approximately 125°C. The unit will cycle on and off while
the fault condition exists. The unit will recover from
shutdown when the cause of the over temperature
condition is removed
Output Voltage Programming
The output voltage of the ND series is trimmable by
connecting an external resistor between the trim pin and
output ground as shown Figure 26 and the typical trim
resistor values are shown in Figure 27.
Figure 26: Trimming Output Voltage
The ND50 module has a trim range of 0.9V to 3.63V.
The trim resistor equation for the ND50A is:
Vout is the output voltage setpoint
Rs is the resistance between Trim and Ground
Rs values should not be less than 3.32k
Output Voltage Rs (Ω)
0.9V open
+1.2 V 38.3k
+1.5 V 18.7k
+1.8V 12.1k
+2.5 V 6.34k
+3.3V 3.92k
+3.63V 3.32k
Figure 27: Typical trim resistor values

DS_ND12S10A_07172008
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Output Capacitance
an external output capacitor(min 680uF) is required for
stable operation.
Voltage Margining Adjustment
Output voltage margin adjusting can be implemented in
the ND modules by connecting a resistor, Rmargin-up, from
the Trim pin to the Ground for margining up the output
voltage. Also, the output voltage can be adjusted lower by
connecting a resistor, Rmargin-down, from the Trim pin to the
voltage source Vt. Figure 29 shows the circuit
configuration for output voltage margining adjustment.
Figure 29: Circuit configuration for output voltage margining
Reflected Ripple Current and Output Ripple and
Noise Measurement
The measurement set-up outlined in Figure 30 has been
used for both input reflected/ terminal ripple current and
output voltage ripple and noise measurements on ND
series converters.
Cs=270F*1, Ltest=1.4uH, Cin=270F*2. Cout=680uF*4
Figure 30: Input reflected ripple/ capacitor ripple current and
output voltage ripple and noise measurement setup for ND50
FEATURES DESCRIPTIONS (CON.)
The output can also be set by an external voltage
connected to trim pin as shown in Figure 28
Figure 28: output voltage trim with voltage source
To use voltage trim, the trim equation for the ND50 is
(please refer to Fig.28):
Vout is the desired output voltage
Vt is the external trim voltage
Rs is the resistance between Trim and Ground (in K)
Rt is the resistor to be defined with the trim voltage (in K)
Below is an example about using this voltage trim equation:
Example:
If Vt=1.25V, desired Vout=2.5V and Rs=1k
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 ale to sink 5mA
and set high when the output is within ±10% of output set
point. The power good signal is pulled low when output is
not within ±10% of Vout or Enable is OFF.

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THERMAL CUREVES `
Figure 32: Temperature measurement location* The allowed
maximum hot spot temperature is defined at 124 ℃
ND12S0A0V50(standard) Output Current vs. Ambient Temperature and Air Velocity
@Vin=12V Vout=0.9V (Through PCB Orientation)
0
5
10
15
20
25
30
35
40
45
50
55
25 30 35 40 45 50 55 60 65 70 75 80 85
Natural
Convection
Output Current (A)
Ambient Temperature (℃)
100LFM
200LFM
Figure 33: Output current vs. ambient temperature and air
velocity @Vin=12V, Vout=0.9V(Through PCB Orientation)
ND12S0A0V50(standard) Output Current vs. Ambient Temperature and Air Velocity
@Vin=12V Vout=2.5V (Through PCB Orientation)
0
5
10
15
20
25
30
35
40
45
50
55
25 30 35 40 45 50 55 60 65 70 75 80 85
Natural
Convection
Output Current (A)
Ambient Temperature (℃)
100LFM
200LFM
300LFM
Figure 34: Output current vs. ambient temperature and air
velocity@ Vin=12V, Vout=2.5V(Through PCB Orientation)
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.
MODULE
A
IR FLOW
11 (0.43”)
50.8 (2.0”)
FACING PWB PWB
AIR VELOCITY
AND AMBIENT
TEMPERATURE
MEASURED BELOW
THE MODULE
22 (0.87”)
Note: Wind tunnel test setup figure dimensions are in
millimeters and (Inches)
Figure 31: Wind tunnel test setup

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MECHANICAL DRAWING
VERTICAL
THERMAL CUREVES
ND12S0A0V50(standard) Output Current vs. Ambient Temperature and Air Velocity
@Vin=12V Vout=3.3V (Through PCB Orientation)
0
5
10
15
20
25
30
35
40
45
50
55
25 30 35 40 45 50 55 60 65 70 75 80 85
Natural
Convection
Output Current (A)
Ambient Temperature (℃)
100LFM
200LFM
400LFM
300LFM
Figure 35: Output current vs. ambient temperature and air
velocity@ Vin=12V, Vout=3.3V(Through PCB Orientation)

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PART NUMBERING SYSTEM
MODEL LIST
Model Name Packaging Input Voltage Output Voltage Output Current Efficiency
12Vin @ 100% load
ND12S0A0V50PNFA Vertical 10.2 ~ 13.8Vdc 0.9 V ~ 3.63Vdc 50A 92.5%
CONTACT: www.delta.com.tw/dcdc
USA:
Telephone:
East Coast: [phone]
West Coast: [phone]
Fax: [phone]
Email: [email protected]
Europe:
Telephone: [phone]
Fax: [phone]
Email: [e-mail]
Asia & the rest of world:
Telephone: [phone] ext. 6220
Fax: [phone]
Email: [email protected]
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.
ND 12 S 0A0 V 50 P N F A
Product
Series Input Voltage Number of
outputs
Output
Voltage Mounting Output
Current
ON/OFF
Logic
Pin
Length
Option
Code
ND-
Non-isolated
Series
12- 10.2~13.8V S- Single
Output
0A0 -
Programmable
V- Vertical 50-50A P- Positive
N- Negative
N- 0.150” F- RoHS 6/6
(Lead Free)
A- Standard
Functions