Product Specification
XL3
3
7
Power Supplies
Document No.
Product Specification
XL3
75 Series
7
5-Watt AC to DC
Power Supplies
Document No.
704601 Rev 03-04-20
704601 Rev 03-04-20
i
Notices
N2Power is a wholly owned subsidiary of Qualstar Corporation.
N2Power and the N2Power logo are registered trademarks of Qualstar Corporation.
Copyright
©
2017 by Qualstar Corporation — All Rights Reserved
For warranty information refer to: http://n2power.com
Information contained in this document is copyrighted by Qualstar Corporation and is
intended for use by customers and prospective customers to evaluate and integrate our
power supplies. Customers and prospective customers may reproduce this document as
needed for these purposes. Reproduction in whole or in part for any other purpose or by
any other party is prohibited without prior written permission from Qualstar
Corporation.
Every effort has been made to keep the information contained in this document current
and accurate as of the date of publication or revision. However, no guarantee is given or
implied that the document is error-free or that it is accurate with regard to any
specification.
N2Power reserves the right to modify the design or specification without notice. This
specification may not be construed as a contractual obligation except as specifically
agreed to by N2Power in writing at the time of order.
For information about this product specification, please write or call N2Power at:
N2Power
1267 Flynn Road
Camarillo, CA 93012
FAX: (805) 978-5212
Phone: (805) 583-7744
E-Mail: sales@n2power.com
www.n2power.com
704601 Rev 03-04-20
ii
Table of Contents
1. Introduction ............................................................................................................................................... 1-1
1.1 Introduction ............................................................................................................................................................... 1-1
1.2 Agency Compliance ................................................................................................................................................. 1-2
2. AC Input ....................................................................................................................................................... 2-1
2.1 Input Line Requirements ..................................................................................................................................... 2-1
2.2 Input Over Current Protection ........................................................................................................................... 2-1
2.3 Inrush Current Limiting ........................................................................................................................................ 2-1
2.4 Low Input Voltage ................................................................................................................................................... 2-1
2.5 Leakage Current ....................................................................................................................................................... 2-2
2.6 Power Factor .............................................................................................................................................................. 2-2
2.7 Safety Warning .......................................................................................................................................................... 2-3
3. DC Outputs .................................................................................................................................................. 3-1
3.1 Output Voltage Regulation................................................................................................................................... 3-1
3.2 Grounding ................................................................................................................................................................... 3-1
3.3 No Load Operation .................................................................................................................................................. 3-1
3.4 Overshoot at Turn On/Turn Off ........................................................................................................................ 3-1
3.5 Voltage Trim............................................................................................................................................................... 3-2
3.6 Output Current/Power .......................................................................................................................................... 3-2
3.7 Efficiency ..................................................................................................................................................................... 3-3
3.8 Unloaded Power Consumption .......................................................................................................................... 3-5
3.9 Cooling .......................................................................................................................................................................... 3-5
3.10 Output Ripple/Noise ........................................................................................................................................ 3-6
3.11 Local and Remote Sensing ............................................................................................................................. 3-7
3.12 Parallel Operation .............................................................................................................................................. 3-8
3.13 Power Supply Protection .............................................................................................................................. 3-10
3.14 Output Transients ............................................................................................................................................ 3-12
3.15 Capacitive Loading .......................................................................................................................................... 3-12
4. General Specifications ............................................................................................................................ 4-1
4.1 Environmental .......................................................................................................................................................... 4-1
4.2 Mean Time between Failures ............................................................................................................................. 4-1
4.3 Component Stress .................................................................................................................................................... 4-1
4.4 Labeling/Marking .................................................................................................................................................... 4-2
4.5 Physical Dimensions ............................................................................................................................................... 4-2
4.6 Weight ........................................................................................................................................................................... 4-3
4.7 Mating Connectors .................................................................................................................................................. 4-3
4.8 Signal Descriptions and Remarks ..................................................................................................................... 4-4
704601 Rev 03-04-20
iii
5. Timing and Control .................................................................................................................................. 5-1
5.1 Power Supply Timing ............................................................................................................................................. 5-1
5.2 Power Good Output ................................................................................................................................................ 5-1
5.3 Remote Enable Input .............................................................................................................................................. 5-2
5.4 Voltage Hold-Up Time ............................................................................................................................................ 5-2
5.5 Output Rise Time ..................................................................................................................................................... 5-2
5.6 LED Indicators ........................................................................................................................................................... 5-2
6. Ordering Information ............................................................................................................................. 6-1
704601 Rev 03-04-20
Introduction 1-1
1. Introduction
1.1 Introduction
This specification defines the design and performance characteristics of an open frame
U-channel single-phase (3 wire) universal input, power factor corrected 375-watt switch
mode power supply. The XL375 models are listed in Table 3-1 and they provide either
260 or 360-watts (model dependent) of filtered and regulated main DC output power at
12V, 24V, 28V, 36V, 40V, 48V, 54V or 56V. When supplied with the Convection Cooling
Option, the power supplies deliver 260-watts without fans. It is the extremely high
efficiency of these supplies that enable them to be packaged in their small 3.3” x 5” x 1.5”
form factor. They all have universal AC inputs to enable operation from 90VAC to
264VAC with power-factor correction to minimize the input current requirements.
All models provide a +5V
standby
output (1.0A max.) whenever AC power is applied. The
main and +12V
standby
outputs are enabled by grounding the Remote Enable input. The
+12V
standby
may be configured to remain on whenever AC power is applied. These single-
output models can be used as standalone power supplies or can be used in redundant or
N+1 configuration with up to 4 units connected in parallel. An optional accessory OR-ing
board is available – see Section 3.12 for details. The +5V
standby
and +12V
standby
outputs
may be wired directly together with other XL375s to provide redundancy, but the
combined output currents are limited to the single-supply values.
704601 Rev 03-04-20
1.2
Agency Compliance
The XL375
complies with the following international agency standards:
Safety
Complies with Standard
United States UL 60950-1
Second Edition
UL 62368-
1 Second Edition
(Information Technology Equipment)
Canada
CSA 22.2: 60950
EU Council 2006/95/EC
International IEC 60950-1
(2005) Second Edition
IEC 62368-
1 (2014) Second Edition
EMC
Complies with Standard
United States
FCC part 15, subpart B
EU Council 2004/108/EC
International EN 61204-
3 (refers to the following)
EN 55022 Class B
EN 55024 (refers to the following)
EN 61000
EN 61000
EN 61000
EN 61000
EN 61000
EN 61000
EN 61000
Reduction of Hazardous Substances (RoHS)
EU Council
Marks of Conformance
United States & Canada
EU Council
RoHS
XL375 Series Product Specification
Introduction
Agency Compliance
complies with the following international agency standards:
Complies with Standard
Remarks
Second Edition
1 Second Edition
(Information Technology Equipment)
Leakage Current –
see table 2
Hi-pot –
2121vdc for 1 second
CSA 22.2: 60950
-1
Low Voltage Directive
(2005) Second Edition
1 (2014) Second Edition
Complies with Standard
Remarks
FCC part 15, subpart B
Conducted emissions
Limits per CISPR 22 Class B
Tested to ANSI C63.4: 2003
EMC Directive
3 (refers to the following)
Low Voltage Power Supplies
EN 55022 Class B
Conducted emissions
Limits per CISPR 22 Class B
EN 55024 (refers to the following)
Immunity
EN 61000
-3-2 Class D
Harmonic Current Emissions
(Power Factor Correction
EN 61000
-3-3
Voltage Fluctuations & Flicker
EN 61000
-4-3
Radiated Susceptibility
EN 61000
-4-4 Fast Transien
t/Burst Immunity
EN 61000
-4-5
Power Mains Surge Immunity
EN 61000
-4-6 RF Immunity
EN 61000
-4-11
Voltage Dips, Short Interruptions
Reduction of Hazardous Substances (RoHS)
Complies with Standard
2002/95/EC
(Underwriters Laboratories File E211115)
Table 1-1 Agency Compliance
10
XL375 Series Product Specification
1-2
-2
– DC Output
– PFC)
Remarks
RoHS Directive
704601 Rev 03-04-20
AC Input 2-1
2. AC Input
2.1 Input Line Requirements
The following table defines the voltage and frequency requirements for the AC line
inputs to the XL375 power supply. The XL375 is capable of supplying full rated power in
continuous operation throughout the specified ranges of voltages and frequencies. The
power supply will automatically recover from AC power loss and is capable of starting
under maximum load at the minimum AC input voltage described below.
Parameter Minimum Rated Maximum
RMS Input Voltage 90 VAC 100–240 VAC 264 VAC
RMS Input Current – – 4.1 A @ 100 V
1.7 A @ 240 V
Input Frequency 47 Hz 50–60 Hz 63 Hz
Table 2-1 XL375 AC Input Parameters
2.2 Input Over Current Protection
The XL375 series incorporates a 6.3A primary AC line fuse for input over current
protection to prevent damage to the power supply and meet product safety
requirements as outlined in Section 1.2.
2.3 Inrush Current Limiting
The cold-start inrush current at a 90-degree phase angle (the AC switch is closed at the
peak of the AC waveform) is limited to 14-amps peak at 240 VAC input voltage and 7-
amps peak at 120 VAC @ 25C.
Repetitive ON/OFF cycling of the AC input voltage should not damage the power supply
or cause the input fuse to fail as long as the power remains off for two or more seconds
when the outputs are unloaded (less depending upon the output loads). The delay is
required for the AC inrush relay to open its contact, upon turning OFF on the power
supply, which allows the inrush current limiter to limit the inrush current to the
specification of 14-amps at 240 VAC and 7-amps at 120 VAC. If you do not wait for at
least 2 seconds the power supply will not be damaged, however the inrush current will
not meet the specification.
2.4 Low Input Voltage
The application of an input voltage below the minimums specified in Table 2-1 shall not
damage the XL375.
XL375 Series Product Specification
704601 Rev 03-04-20
AC Input 2-2
2.5 Leakage Current
The leakage current from AC line or AC Neutral inputs to Protective Earth varies linearly
with the input voltage and frequency (see operating column of Table 2-2). The leakage
currents of multiple power supplies are additive. Consult the appropriate electrical
safety specification for the maximum leakage current permitted in your product. The
leakage current will always go to zero when a DPDT switch simultaneously disconnects
both the line and neutral circuits. A single fault can occur when the AC power is applied
to only the Neutral input terminal.
Line Voltage
Frequency
Operating
Single Fault
(see text)
120VAC, 60Hz 0.40 mA 0.75 mA
240VAC, 60Hz 0.80 mA 1.50 mA
240VAC, 50Hz 0.65 mA 1.25 mA
Table 2-2 Leakage Current – Single XL375
2.6 Power Factor
The XL375 power factor exceeds 0.94 with loads of 225-watts or greater at 230VAC. It
exceeds 0.98 with loads of 225-watts or greater at 115VAC
Figure 2-1 Power Factor, Typical
0
0.2
0.4
0.6
0.8
1
1.2
0% 20% 40% 60% 80% 100% 120%
Output Power
Power Factor
230VAC
115VAC
XL375 Series Product Specification
704601 Rev 03-04-20
AC Input 2-3
2.7 Safety Warning
WARNING
The XL375 is a component, not a stand-alone power supply. It must be mounted
inside a protective enclosure to prevent accidental shock by contact with the
supply. Lethal voltages are present while and after AC power is applied to the
XL375. Allow 1-minute for storage capacitors to discharge after removing AC
power before handling the XL375.
The safety ground connection is the chassis itself and it must be connected to
Protective Earth. All four bottom-side mounting screws must always be installed
and torqued to 5 in-lb.
The user must keep any bare metal at least 2.6mm from the AC input connector
J1. An insulator can be used between J1 and the bare metal to decrease this
spacing.
704601 Rev 03-04-20
DC Outputs 3-1
3. DC Outputs
3.1 Output Voltage Regulation
The DC output voltages shall remain within the minimum and maximum limits of
Table 3-1
when measured at the power supply connector under all specified line and
environmental conditions contained herein. The regulation accuracy is measured with
load currents between zero and the maximum load currents listed in Table 3-3.
Model Output Rated
Voltage
Regulation
Minimum
(VDC)
Nominal
(VDC)
Maximum
(VDC)
Remote
Sense
XL375-12 V1 +12 V ±3% 11.64 12.0 12.36 V1/RTN
XL375-24 V1 +24 V ±3% 23.28 24.0 24.72 V1/RTN
XL375-28 V1 +28 V ±3% 27.16 28.0 28.84 V1/RTN
XL375-36 V1 +36 V ±3% 34.92 36.0 37.08 V1/RTN
XL375-40 V1 +40 V ±3% 38.80 40.0 41.20 V1/RTN
XL375-48 V1 +48 V ±3% 46.56 48.0 49.44 V1/RTN
XL375-54 V1 +54 V ±3% 52.40 54.0 55.62 V1/RTN
XL375-56 V1 +56 V ±3% 54.32 56.0 57.68 V1/RTN
All V2 +12 V
standby
±5% 11.40 12.0 12.60 None
V3 +5 V
standby
±5% 4.75 5.0 5.25 None
Table 3-1 XL375 Output Voltage Specifications
3.2 Grounding
All DC outputs, status outputs and control inputs share a common DC Return found on
all output connectors. DC Return floats from the chassis (Protective Earth) with a 68nF,
630V capacitor between them.
3.3 No Load Operation
A no load condition will not damage the supply or cause a hazardous condition. The
power supply will remain stable and operate normally after application of a load. The
Power Good logic output will indicate normal operation when the supply is unloaded.
3.4 Overshoot at Turn On/Turn Off
The output voltage overshoot upon the application or removal of the input mains
voltage is less than 10% above the nominal voltage. No opposite polarity voltage is
present on any output during turn on or turn off.
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-2
3.5 Voltage Trim
If voltage trim is not required, the TRIM input should be left unconnected. The voltage
trim input pin is provided to allow the user to adjust the V1 output up or down by up to
5%. Connecting a resistor between this pin and DC Return will increase the output
voltage while connecting a resistor between this pin and the V1 output will decrease the
output voltage. The ability of the V1 output to maintain its specified regulation accuracy
under severe load or line conditions could be diminished by trimming the output to a
higher than nominal voltage. The trim range is limited to +/- 5% as determined by the
Up/Down 5% resistor values listed in Table Table 3-2. For increased output voltage, use
only resistance values greater than or equal to those listed.
Model V1 Up 3% V1 Up 5% V1 Down 3% V1 Down 5%
Connect Trim
pin to
to DC
Return
to DC
Return
V1 Output V1 Output
XL375-12 (12V) 133K Zero 1.27M 549K
XL375-24 (24V) 133K Zero 2.80M 1.43M
XL375-28 (28V) 133K Zero 3.32M 1.74M
XL375-36 (36V) 133K Zero 4.42M 2.43M
XL375-40 (40V) 133K Zero 4.87M 2.67M
XL375-48 (48V) 133K Zero 5.90M 3.24M
XL375-54 (54V) 133K Zero 6.65M 3.65M
XL375-56 (56V) 133K Zero 6.98M 3.92M
Table 3-2 Minimum Trim Resistors for Maximum Trim
When two or more XL375’s are operating in parallel, each unit should be trimmed with
the same resistor value. The TRIM input is connected through a 200K resistor to the
voltage control loop input of the XL375 and should never be connected to anything but a
resistor mounted as close as possible to J204. Long wiring to a trim resistor can pickup
noise and could find its way to the output terminals. Do not connect the TRIM inputs
from multiple supplies together.
3.6 Output Current/Power
The maximum available output power is always a function of the cooling airflow and its
temperature. The maximum of 375-watts combined total power from all outputs is only
available with a minimum of 10-CFM of forced air-cooling at no more than 50°C. Each
individual output is also limited: V1 output is limited to 360-watts, +12 V
standby
is limited
to 12-watts and +5 V
standby
is limited to 5-watts.
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-3
Model Output Rated
Voltage
Maximum
Load
XL375-12 CS V1 (main) 12 V 30.0A
XL375-12 CS CC V1 (main) 12 V 21.6A
XL375-24 CS V1 (main) 24 V 15.0 A
XL375-24 CS CC V1 (main) 24 V 10.8 A
XL375-28 CS V1 (main) 28 V 12.8 A
XL375-28 CS CC V1 (main) 28 V 9.2 A
XL375-36 CS V1 (main) 36 V 10.0 A
XL375-36 CS CC V1 (main) 36 V 7.2 A
XL375-40 CS V1 (main) 40 V 9.0 A
XL375-40 CS CC V1 (main) 40 V 6.5 A
XL375-48 CS V1 (main) 48 V 7.5 A
XL375-48 CS CC V1 (main) 48 V 5.4 A
XL375-54 CS V1 (main) 54 V 6.7 A
XL375-54 CS CC V1 (main) 54 V 4.8 A
XL375-56 CS V1 (main) 56 V 6.4 A
XL375-56 CS CC V1 (main) 56 V 4.6 A
All +5 V
standby
5 V 1.0 A
All +12 V
standby
12 V 1.0 A
CS = Current Sharing, CC = Convection Cooling
Table 3-3 Maximum Individual Continuous Load Currents
(sum limited to 375W for CS and 260W for CC)
3.7 Efficiency
The power supply efficiency varies with the output load and the line voltage. Higher
voltage power supplies will exhibit slightly higher efficiencies due to lower output
currents (less I x R losses). Efficiency data is measured at 25C with 10-CFM of cooling air
after a 15-minute warm-up period. The measurements were taken at 10% intervals to
360W (100%) main output power. The +5 V
standby
and +12 V
standby
outputs were
unloaded.
The least efficient model is the XL375-12 and its main output efficiency is greater than
89% for 115VAC and 90% for 230VAC inputs with loads ranging from 50% to 100% of
the rated main output power. Peak efficiencies are approximately 90% and 91.5%
respectively.
The XL375-48 is typical of the higher output voltage models and its main output
efficiency is greater than 90.5% for 115VAC and 91.5% for 230VAC inputs with loads
ranging from 50% to 100% of the rated main output power. Peak efficiencies are
approximately 91.6% and 93.3% respectively.
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-4
Figure 3-1 Typical XL375-12 (12V, worse-case) Efficiency Curves (note expanded Y-axis)
Figure 3-2 Typical XL375-48 Efficiency (note expanded Y-axis)
XL375-12
50.0%
55.0%
60.0%
65.0%
70.0%
75.0%
80.0%
85.0%
90.0%
95.0%
0% 20% 40% 60% 80% 100% 120%
Percent of Main Output Power
Efficiency
230VAC 115VAC
XL375-48
50.0%
55.0%
60.0%
65.0%
70.0%
75.0%
80.0%
85.0%
90.0%
95.0%
0% 20% 40% 60% 80% 100% 120%
Percent of Main Output Power
Efficiency
230VAC 115VAC
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-5
3.8 Unloaded Power Consumption
When completely unloaded and at any normal input voltage, the XL375 consumes about
3-watts with a high (open) Remote Enable input (standby state) and about 9-watts with
a low (grounded) Remote Enable input (V1 on but unloaded). The power-factor does not
meet its specification under these conditions.
3.9 Cooling
The XL375 can operate with the Convection Cooling Option at temperatures below 50°C
when total power output is less than 260 watts and it is mounted open side up. 10-CFM
of forced-air cooling at a maximum of 50°C is required when the output power exceeds
260-watts. The cooling airflow must be either co-planar with the circuit board or it must
impinge downward in the center of the open topside. The XL375 may be mounted in any
attitude when forced-air cooled.
3.9.1 Output Power Derating at Elevated Temperatures
The XL375 can be operated with cooling air temperatures above 50C by linearly
derating the total maximum output power (or current) by 2.5%/C from 50C to 70C
(see Figure 3-3).
-25 0 25 50 70
Degrees C
0
50%
100%
% Load
Figure 3-3 XL375 Output Power vs. Ambient Temperature Envelope
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-6
3.9.2 Over-temperature Shutdown
The power supply is equipped with an internal temperature sensor. Failure to provide
adequate cooling airflow below the maximum operating temperature will result in the
power supply shutting down the V1 output while the +5V
standby
and +12V
standby
outputs
will remain operational. The V1 output will be automatically restored when the
temperature of the built-in temperature sensor cools sufficiently.
3.10 Output Ripple/Noise
Output ripple voltage and noise are defined as periodic or random signals over a
frequency band of 10 Hz to 20 MHz. Measurements are to be made with an oscilloscope
with a 20 MHz bandwidth. Outputs should be bypassed at the connector with a 0.1 F
ceramic disk capacitor and a 10 F tantalum capacitor to simulate system loading (see
Figure 3-4). Ripple and noise shall not exceed the limits specified in the following tables.
The ripple voltage of the output is measured at the pins of the mating connector. Ripple
and noise shall not exceed the limits specified in Table 3-4 under any condition of line
voltage and frequency specified in Section 2.1 and DC loading specified in Section 3.5.
Model Output Rated
Voltage
Maximum Ripple+Noise
(peak-to-peak)
XL375-12 V1 (main) +12 V 100 mV
XL375-24 V1 (main) +24 V 200 mV
XL375-28 V1 (main) +28 V 200 mV
XL375-36 V1 (main) +36 V 200 mV
XL375-40 V1 (main) +48 V 200 mV
XL375-48 V1 (main) +48 V 200 mV
XL375-54 V1 (main) +54 V 200 mV
XL375-56 V1 (main) +56 V 200 mV
All V2 (+12 V
standby
) +12 V 80 mV
All V3 (+5 V
standby
) +5 V 50 mV
Table 3-4 Ripple + Noise Output Voltage
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-7
3.10.1 Ripple/Noise Test Setup
Power Supply
AC Line
AC Neutral
V Out
DC Return
AC Ground
Load
Load must be
isolated from the
ground of the
power supply.
Differential
Oscilloscope
10uf 0.1uf
Notes:
1. Load the output with its minimal
load current.
2. Connect the probes as shown but
keep them as close as possible to
the J2 (output) connector.
3. Repeat the measurement with
maximum load on the output.
Figure 3-4 Ripple Noise Measurement Setup
3.11 Local and Remote Sensing
Remote sensing is provided to compensate for voltage drops in the V1+ Output and the
DC Return wiring to the V1 load. The voltage droop (wiring loss) between the XL375
output terminals and their respective remote sense inputs should be kept to a maximum
of 0.4-volts. Reversing the + and – sense lines may permanently damage the XL375.
If the Remote Sense inputs are left open, the output voltage at the J14 and J15 terminals
may not meet the voltage regulation specification. The remote sense lines should either
be connected to the XL375 output terminals or extended through the bulkhead
connectors up to the critical load within a user’s system. Connecting the remote sense
inputs lifts the voltage at the load to within the specification voltage regulation limits but
may increase the V1 voltage at J14 and J15 above the regulation limits. See Figure 3-5.
V1 Sense +
+ V1
RETURN
V1 Sense -
XL375
J204-3
J15
J204-2
LOAD
J14
Figure 3-5 Remote Sense Wiring
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-8
3.12 Parallel Operation
By using the built-in active current-sharing, the V1 output of two, three or four XL375
power supplies may be connected in parallel to provide higher V1 output power as
shown in Table 3-5. They can also be used in an N+1 configuration to provide greater
reliability. Remote V1 sensing may still be used in parallel operation. The V2 and V3
outputs may also be paralleled for improved reliability, but doing so does not increase
the available current beyond 1A.
Only the main output is capable of current sharing. Because of the inherent limitations of
current sharing, it is recommended that the total load not exceed 92%-94% of the sum
of the rated outputs (see Table 3-5). Current sharing accuracy drops with the total load
power, thus a minimum V1 load of 35-watts per power supply is recommended. The
following table lists the recommended maximum V1 output power.
Number of XL375s N+1 Configuration
2 670 watts
3 995 watts
4 1325 watts
Table 3-5 Recommended Main Output Power for N+1 Configurations
XL375s running in parallel are capable of starting with a V1 load that exceeds the
capability of an individual XL375. They will also tolerate the dramatic load fluctuations
encountered in an N+1 redundant configuration when supplies are removed and
replaced.
Current-sharing operates normally when the V1 outputs of two XL375 are hard-wired in
parallel, but this is not considered an N+1 connection. If the two V1 outputs (wired in
parallel) were producing half-power each and the input power fails on one of the
supplies, the other supply will continue to provide full power to the load. However, if the
output synchronous rectifiers failed on one of the supplies, then the V1 output would
most likely be shorted and the load would be without power. Hot swapping two units
connected in parallel will likely create voltage transients well outside of the voltage
regulation tolerance.
The above scenario did not make use of an OR-ing diode on the V1 output of each supply.
N2Power can supply an active OR-ing Diode accessory board that bolts onto the V1
output terminals and provides two new output screw terminals (see Figure 3-6). The
ground connections are wired directly together, but there is a MOSFET (or pair of
MOSFETs) between the supply’s output terminal and the OR-ing board’s output
terminal. A sophisticated analog controller monitors the voltage difference between the
supply’s voltage and the bus voltage and then controls the MOSFET gate voltage to
simulate a near-perfect diode with a forward voltage drop of less than 50mV. For further
details, see document 704693. Use of this OR-ing board facilitates hot-swapping and
prevents a shorted supply output from dragging down the bus voltage.
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-9
Figure 3-6 XL375 with optional OR-ing Diode Accessory Board Attached
3.12.1 Current Sharing Connections
The Current Share signal (V1 I-Share) of each supply operating in parallel must be
connected together. Power sharing does not require the Remote Sense signals be
connected together, but the sharing accuracy will be reduced unless they are all
connected together.
Individual Power Good signals must not be wire ORed together. Each individual Power
Good signal should be monitored separately by the user’s system.
V1 Sense +
+ V1
RETURN
V1 Sense -
XL375
J204-3
J204-2
LOAD
J204-1
Current Share
+
-
V1 Sense +
+ V1
RETURN
V1 Sense -
XL375
J204-3
J204-2
J204-1
Current Share
J14
J15
J14
J15
Figure 3-7 Current Sharing Wiring Example
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-10
3.12.2 Current Share Accuracy
When all the current share signals are connected together and all the Remote Sense
signals are connected together, the load delivered by any two of the sharing supplies will
not vary by more than 10% at full load. Sharing accuracy deteriorates with declining
load power.
3.12.3 +5 V
standby
Parallel Operation
The +5 V
standby
output has a series Schottky rectifier just before the output connector that
allows this output to be connected in parallel with the same output on like supplies. By
doing so, the +5 V
standby
output will remain alive as long as one of the paralleled supplies
is functioning. The output current rating does not increase beyond the single supply
rating.
3.12.4 +12 V
standby
Parallel Operation
The +12 V
standby
output has a series Schottky rectifier just before the output connector
that allows this output to be connected in parallel with other the same output on like
supplies. By doing so, the +12 V
standby
output will remain alive as long as one of the
paralleled supplies is functioning. The output current rating does not increase beyond
the single supply rating.
3.12.5 Transients
The output rise time and monotonic requirements of Section 5.5 may not be met when
the main load exceeds 360-watts, because of the difference in start-up times of the
paralleled power supplies.
3.13 Power Supply Protection
There are several different protection circuits designed to protect the load and the
XL375 from component failures and extraordinary circumstances.
3.13.1 Over Temperature Protection (OTP)
If the XL375 is operated without adequate cooling, it will sense an over-temperature
condition and shut down the V1 (main) output. It will restart after it has cooled down to
below its maximum operating temperature. The PG signal and LED go false about 2mS
before the V1 output is disabled. The V2 and V3 outputs are unaffected by a V1 OTP
condition.
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-11
3.13.2 Over-Voltage Protection (OVP)
Over-voltage protection is only provided on the V1 (main) output. When an over-voltage
condition occurs (approximately 114% of rated output voltage), the power supply will
shut down and will not restart until AC power is turned off and back on. The XL375 will
shut down under the following over voltage conditions:
Over-Voltage Protection Threshold
Model Main Output Minimum Nominal Maximum
XL375-12 12 V 12.8 V 13.4 V 14.0 V
XL375-24 24 V 26.0 V 27.3 V 28.7 V
XL375-28 28 V 29.2 V 31.2 V 33.2 V
XL375-36 36 V 40.1 V 43.1 V 46.1 V
XL375-40 40 V 44.7 V 47.0 V 49.4 V
XL375-48 48 V 53.2 V 56.0 V 58.8 V
XL375-54 54 V 59.2 V 62.3 V 65.4 V
XL375-56 56 V 60.1 V 63.2 V 66.3 V
Table 3-6 Over Voltage Protection Limits
3.13.3 Over Current Protection (OCP)
An excessive load on the V1 output will induce constant-current limiting which will
cause the output voltage to droop. The constant-current limiter has a threshold of
approximately 115% (+/- 5%) of the rated output current. The V1 current-limiter is not
affected by the V2 and V3 loads.
An under-voltage detector (UVD) turns off the Power Good output signal and LED when
the output voltage falls below about 83% of the specified nominal and restores them to
the on state when the output voltage rises above about 86%.
The under-voltage protection (UVP) circuit will shut the output off when the output
voltage falls below about 67%. The XL375 will attempt to restart approximately 6-
seconds after the UVP event. If the load current is low enough to allow the output
voltage to exceed 67%, the supply will remain on. If not, it will attempt another restart
in another 6-seconds.
3.13.4 Short Circuit Protection (SCP)
A short circuit on any output will disable that output but will not damage the XL375. A
short on the V2 (+12 V
standby
) output will disable all outputs. The XL375 will periodically
attempt to restart until the short circuit condition is removed. After successfully
restarting, the power supply will operate normally.
XL375 Series Product Specification
704601 Rev 03-04-20
DC Outputs 3-12
3.14 Output Transients
The maximum output voltage transient caused by step load changes will not exceed the
output voltage regulation limits by more than 5%. With an AC input as specified in
Section 2.1, the power supply will remain stable when subjected to the load transients
described below with capacitive loading per Table 3-7:
Load changes between 75% and 100% on any output
Load changing repetition of 50 to 333 cycles per second
Transient load slew rate = 1.0 A/microsecond
3.15 Capacitive Loading
The XL375 will startup and operate normally with load capacitances simultaneously
present on the all outputs not exceeding those listed in Table 3-7.
Output XL375-12
XL375-24/28 XL375-36…56
V1 (12 V) 50,000 μF
V1 (24 V…28 V) 12,000 μF
V1 (36V…56 V) 3,000 μF
V2 (+12 V
standby)
180 μF 180 μF 180 μF
V3 (+5 V
standby)
220 μF 220 μF 220 μF
Table 3-7 XL375 Maximum Capacitive Loading
704601 Rev 03-04-20
General Specifications 4-1
4. General Specifications
4.1 Environmental
The XL375 meets or exceeds the following environmental specifications:
Parameter Conditions Specification Remarks
Temperature Operating -25°C to 70°C See cooling requirements
Non-Operating -40°C to 85°C
Relative Humidity Operating 95% Maximum Non-Condensing
Non-Operating 95% Maximum Non-Condensing
Altitude Operating 6,561 feet MSL Max. 2,000 meters
Non-Operating 50,000 feet MSL Max. 15,240 meters
Vibration No damage 2.4G RMS Maximum 5-500Hz, 10-min. each axis per
MIL-PRF-28800F: 3.8.4.1 (Class 3,4)
Mechanical Shock No damage 30G half-sine, 11mS Six shocks each axis per
MIL-PRF-28800F: 4.5.5.4.1
Table 4-1 Environmental Specifications
The XL375 will start and meet its performance specifications within the environmental
conditions listed in Table 4-1. It has also been demonstrated that the XL375 will start
reliably at -40°C with an input voltage of 100VAC or greater. Consult N2Power for
technical details.
4.2 Mean Time between Failures
The calculated MTBF of the power supply is equal to or greater than 376,644 hours of
continuous operation at maximum output loading and worst case input line voltage with
forced-air cooling at 25°C. N2Power does not warrant the MTBF to be representative of
any particular unit. The MTBF of the power supply is calculated with an 80% confidence
level in accordance with Bellcore, SR-332, Issue 2. Actual failure rates vary from unit to
unit.
4.3 Component Stress
The XL375 was designed with the following component-derating guidelines at an
operating ambient temperature of 50C: semiconductor junction temperatures shall not
exceed ninety 90 % of manufacturer’s rating. Inductor winding temperatures shall not
exceed safety agency requirements. Electrolytic capacitor case temperatures shall not
exceed 95% of rated temperature. Resistor power dissipation shall not exceed 70% of
rated while other components will not be operated at more then 90% of their rated
voltage or current.
XL375 Series Product Specification
704601 Rev 03-04-20
General Specifications 4-2
4.4 Labeling/Marking
The power supply is marked and labeled with the N2Power logo model number, part
number, input and output specifications, production code, appropriate safety agency
logos, CE mark, and country of origin. An example label is pictured below.
Figure 4-1 Sample XL375 Label
4.5 Physical Dimensions
3D CAD models are available by contacting sales@n2power.com.
Figure 4-2 XL375 Series Dimensions
.26
(6.6)
5.00
(127.0)
J14 (+)
J15 (-)
Dimensions in inches (mm)
J1
Pin-1
.225
(5.7)
4.55
(115.6)
4.55
(115.6)
4x 6-32 Standoffs
J204
.75
(19.1)
XL375
J204
3.33
(84.6) Pin 1
Remove the four 6-32 x 3/8” 100° flathead Phillips screws from the
bottom of the XL275 and use them to mount the supply to your chassis
(up to 2mm or .08” thick). Tighten them securely (5 in-lb or 0.6N-m) to
assure safety ground (Protective Earth) continuity.
1.50
(38.1)
2.55
(64.8)
.39
(9.9)
4x Pem Nut 6-32
(both sides)
4x Pem Nut 6-32
(both sides)
XL375 Series Product Specification
704601 Rev 03-04-20
General Specifications 4-3
4.6 Weight
Units Net Weight
Pounds 0.94
Ounces 15
Kilograms 0.43
Table 4-2 XL375 Weight
4.7 Mating Connectors
The user must furnish all mating connectors. The mating connectors must meet the
requirements of all applicable safety agencies (notably UL).
Note that the female contacts that mate to the power supply are only rated for 25-30
mating cycles. Excessive mating cycles causes dramatically increased terminal resistance
and heating resulting in the eventual failure of the mating terminal and possibly the
header on the power supply.
4.7.1 AC Input Mating Connector (J1)
The AC input connector to the XL375 is a 3-pin Molex (Molex is a trademark of the
Molex Corporation) KK style header with 0.156” centers. The center pin is omitted to
provide adequate insulation spacing. The Molex part numbers for the mating housing
and crimp-style snap-in terminals are listed below. There may be equivalent connectors
available from other manufacturers. A minimum of AWG 18 wire is recommended.
J1 Molex P/N
Connector Circuits (pins) 2 of 3
Mating Housing 09-50-8031
Rated Contact Current 7.0 A
Crimp Terminal (tin) 08-50-0113
Rated Wire Size AWG 18 or 20
Table 4-3 J1 Mating Connector
4.7.2 Protective Earth (J2)
The chassis must be connected to protective earth at either J2 or the mounting hole next
to J2. J2 is a quarter-inch male push-on (Faston) terminal.
XL375 Series Product Specification
704601 Rev 03-04-20
General Specifications 4-4
4.7.3 DC Output Terminals (J14 and J15)
The DC output terminals are designed to accept a ring-lug terminal. There are many
sources available. A minimum of AWG 16 wire is recommended. The lugs must have a
minimum I.D. of 0.140” [3.53mm] and a maximum O.D. of 0.32” [8.1mm]. The lugs must
be contaminant free and should be tightened to a torque of approximately 8-inch-
pounds [0.9 N-m]. The positive terminal is on the left. These terminals use 6-32 UNC
screws.
4.7.4 Auxiliary Connector (J204)
The auxiliary connector on the XL375 is a Molex KK header with 0.100” centers. The
Molex part numbers for the mating housing and crimp-style snap-in terminals are listed
below. There may be equivalent connectors available from other manufacturers.
J204 Molex P/N
Connector Circuits (pins) 9
Mating Housing 22-01-3097
Crimp terminal (selective gold) 08-55-0102
Rated Contact Current 2.5 A
Rated Wire Size AWG 22 thru 30
Table 4-4 J204 Mating Connectors
4.8 Signal Descriptions and Remarks
Signal Description/Remarks
AC Line Highest in potential compared to earth ground. Should be
connected to the AC power switch.
AC Neutral Closest in potential to earth ground. Should not be connected to
a single-pole power switch.
DC Return XL375 ground for all outputs and status/control signals.
V1 The main output (+)
V1 Sense (+) Remote sense for V1 at load (compensates for wiring losses)
V1 Sense (-) Remote sense for DC Return at load (affects V1, see above)
V1 Trim Adjusts V1 output voltage up to +/- 5% using an external
resistor. See Section 3.5
V1 I-Share Current Share Signal common to all sharing XL375s
V2 (+12V
standby
) Provides 1A of 12V power for fans. Uses common ground DC
Return.
V3 (+5 V
standby
) Provides 1A of 5V power whenever AC power is presents. Uses
common ground DC Return
Remote Enable Low-true logic input enables V1 output
Power Good A high-logic level (4.5V) indicates the output power is in
regulation for at least the next 2mS. See Section 5.2
Table 4-5 Signal Descriptions and Remarks (All outputs and inputs are referenced to DC Return)
XL375 Series Product Specification
704601 Rev 03-04-20
General Specifications 4-5
Pin Signal
J1-1 AC Neutral
J1-2 No Pin
J1-3 AC Line
Pin Signal
J2 Protective Earth
Pin Signal
J14 V1 + Output
J15 V1 DC Return (Output Ground)
Pin Signal
J204-1 V1 I-Share
J204-2 V1 Sense (–)
J204-3 V1 Sense (+)
J204-4 V3 (+5V
standby
)
J204-5 V1 Trim Input
J204-6 V2 (+12V
standby
)
J204-7 DC Return (Output Ground)
J204-8 Remote Enable (logic input, low-true)
J204-9 Power Good (logic output, high-true)
Table 4-6 Pin Assignments in Pin Order
704601 Rev 03-04-20
Timing and Control 5-1
5. Timing and Control
5.1 Power Supply Timing
VAC
V1
POWER
GOOD
Reg.
10%
T1
T2
T4
T3
T5
T6
T1
T2
T3
T4
T5
T6
Min Max
1.5S
<50
µ
S*
>20mS
>2mS
500mS
20mS
--
--
--
90%
* No Load Capacitance
Reg.
10%
90%
--
--
--
--
--
--
--
Figure 5-1 XL375 Timing Diagram
5.2 Power Good Output
The Power Good signal provides a high logic level to indicate the DC outputs are within
their regulation limits and that sufficient mains energy is stored by the power supply to
ensure continuous power operation within specification for the duration of the hold-up
time. When the AC mains power is removed for a period longer than 20ms, the Power
Good signal transitions to a low logic level. The Power Good signal (CMOS output) is
capable of sinking or sourcing 4mA from an internal 5.0V supply.
XL375 Series Product Specification
704601 Rev 03-04-20
Timing and Control 5-2
5.3 Remote Enable Input
This input must be grounded to enable the V1 (main) output. It has no effect on the
+5V
standby
and +12V
standby
outputs. It is pulled-up to 5.0V through a 6.8K-ohm resistor.
The input voltage must be less than 0.4V to activate the V1 output and higher than 3.0V
to disable the output.
An optional S91 modification is available on special order that inverts the Remote
Enable input to a high-true input with a 6.8K pull-down resistor. Contact sales for
details.
5.4 Voltage Hold-Up Time
The power supply will maintain output regulation for a minimum of 22 milliseconds
(per Table 3-1
),
despite a loss of input power at 100VAC/50Hz or 230VAC/50Hz at
maximum continuous output load.
5.5 Output Rise Time
All output voltages from a single XL375 shall rise monotonically (always positive
slope) from 10% to 90% of their nominal output voltage (as specified in Table 3-1)
within 0.2ms to 30ms under any loading conditions (as specified in Table 3-3).
The rise of the shared V1 output from two or more XL375s operating in parallel may
not be monotonic.
5.6 LED Indicators
There are two LED indicators mounted near the top of the daughter board behind J204
(See Figure 4-2). An amber LED indicates the +5V
standby
is energized (AC input power is
present). A green LED illuminates whenever the Power Good signal is true (high). This
indicates the main output is on and regulating.
704601 Rev 03-04-20
Ordering Information 6-1
6. Ordering Information
The CS suffix after the part number stands for Current-Sharing and the CC stands for
Convection Cooling. All XL375s are active current-sharing capable but require an
external OR-ing diode or an Active OR-ing accessory board to isolate V1 outputs for
improved reliability or hot swapping. See Section 3.12. The following table provides the
N2Power part numbers that should appear on your purchase order and will appear on
any N2Power correspondence:
Model Number V1
XL375
N2Power
Part Number
Optional Active
OR-ing Board
Part Number
XL375-12 CS 12 V 400040-01-0 400040-02-8
XL375-12 CS CC 12 V 400040-04-0 400040-02-8
XL375-24 CS 24 V 400041-01-8 400041-02-6
XL375-24 CS CC 24 V 400041-05-9 400041-02-6
XL375-28 CS 28 V 400052-01-5 400052-02-3
XL375-28 CS CC 28 V 400052-03-1 400052-02-3
XL375-36 CS 36 V 400046-01-7 400052-02-3
XL375-36 CS CC 36 V 400046-03-3 400052-02-3
XL375-40 CS 40 V 400045-01-9 400052-02-3
XL375-40 CS CC 40 V 400045-03-5 400052-02-3
XL375-48 CS 48 V 400042-01-6 400052-02-3
XL375-48 CS CC 48 V 400042-04-0 400052-02-3
XL375-54 CS 54 V 400044-01-2
400044-02-0
XL375-54 CS CC 54 V 400044-03-8
400044-02-0
XL375-56 CS 56 V 400043-01-4 400044-02-0
XL375-56 CS CC 56 V 400043-03-0 400044-02-0
Table 6-1 XL375 Part Numbers
For warranty information refer to www.n2power.com
All XL375 power supplies are RoHS compliant.
XL375 Series Product Specification
704601 Rev 03-04-20
Ordering Information 6-2
Direct all questions, orders or requests for quotation as follows:
N2Power Order Desk: orders@n2power.com
805-583-7744 x112
Fax (Attention N2Power): 805-978-5212
Sales: sales@n2power.com
805-583-7744 x122
Technical Support techsupport@n2power.com
805-583-7744 x119
Street Address: 1267 Flynn Road
Camarillo, CA 93012