A
20 Watt HP Triple Series DC/DC Converters
2401 Stanwell Drive Concord, California 94520 Ph: 925/687-4411 or 800/542-3355 Fax: 925/687-3333 www.calex.com Email: sales@calex.com
1
3/2001, eco# 041007-1
Features
High Power Density with Efficiencies to 86%
Lowest Noise Outputs, 50 mV P-P
Very Low and Specified Reflected Ripple Current
Very Low 400 pF I/O Capacitance
Water Washable Shielded Copper Case
Five Year Warranty
Description
The HP series is a high performance 20 watt triple output DC/
DC converter designed for battery and telecom systems. The
wide 2:1 input voltage ranges cover nearly any input voltage
from 9 to 72 VDC.
The most popular +5 and 12 or 15 output voltages are
provided in 6 models for your convenience. Other voltages
may be factory ordered, contact CALEX applications
engineering at 1-800-542-3355 for more information.
Available options include a fully filtered input version for
use where the supply must operate in a low reflected noise
environment. A thermal overload protection option makes the
supply nearly bullet proof to any fault condition, including loss
or blockage of your systems cooling!
Full application information is provided to make integrating
this supply in your system a snap.
20 Watt HP Triple Series Block Diagram
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20 Watt HP Triple Series DC/DC Converters
2401 Stanwell Drive Concord, California 94520 Ph: 925/687-4411 or 800/542-3355 Fax: 925/687-3333 www.calex.com Email: sales@calex.com
2
3/2001, eco# 041007-1
NOTES
*
All parameters measured at TC = 25C, nominal input
voltage and full rated load unless otherwise noted.
Refer to the CALEX Application Notes for the definition
of terms, measurement circuits and other information.
(1)
See the power derating curve for information on the 12T models
available output power.
(2)
Noise is measured per CALEX application notes. Measurement
bandwidth is 0 - 20 MHz. RMS noise is measured over a 0.01-
1 MHz bandwidth. To simulate standard PCB decoupling
practices, output noise is measured with a 1F, tantalum and
0.01F, ceramic capacitor located 1 inch away from the converter.
Input ripple is measured into a 10H source impedance. Input
Reflected Ripple is for -FT option. For input ripple without the -
FT option see the applications section.
(3)
Optimum performance is obtained when this power supply
is operated within the minimum to maximum load specifications.
(4)
Output regulation is specified by simultaneously changing all
outputs from minimum to maximum load and noting the change
in each output.
(5)
Cross regulation is defined as the change in one output when
only one of the other outputs is changed from maximum to
minimum load.
(6)
Short term stability is specified after a 30 minute warm up at full
load, constant line, load and ambient conditions.
(7)
Transient response is defined as the time for the output to settle
from a 50 to 75% step load change to a 1% error band (rise time
of step = 2s).
(8)
Dynamic response is defined as the peak overshoot during
a transient as defined in note 7 above.
(9)
The functional temperature range is intended to give an additional
data point for use in evaluating this power supply. At the
low functional temperature the power supply will function with
no side effects. Sustained operation at the high functional
temperature will reduce the expected operational life. The data
sheet specifications are not guaranteed over the functional
temperature range.
(10) The case thermal impedance is specified as the case temperature
rise over ambient per package watt dissipated.
(11) Specifications subject to change without notice.
(12) Water Washability - Calex DC/DC converters are designed to
withstand most solder/wash processes. Careful attention should
be used when assessing the applicability in your specific
manufacturing process. Converters are not hermetically sealed.
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20 Watt HP Triple Series DC/DC Converters
2401 Stanwell Drive Concord, California 94520 Ph: 925/687-4411 or 800/542-3355 Fax: 925/687-3333 www.calex.com Email: sales@calex.com
3
3/2001, eco# 041007-1
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BOTTOM VIEW
SIDE VIEW
Mechanical tolerances unless otherwise noted:
X.XX dimensions: 0.020 inches
X.XXX dimensions: 0.005 inches
Applications Information
You truly get what you pay for in a CALEX converter, a
complete system oriented and specified DC/DC converter -
no surprises, just "plug and play".
The 20 Watt HP Triple series like all CALEX converters
carries the full 5 year CALEX no hassle warranty. We can offer
a five year warranty where others can't because with CALEX
it's rarely needed.
Keep reading, you'll find out why.
General Information
The HP Triple series is mindful of battery operation for
industrial, medical control and remote data collection
applications. The optional remote ON/OFF pin (-FT option)
places the converter in a very low power mode that draws
typically less than 3 mA from the input source.
Noise has also achieved new lows in this design, while the
industry standard is to specify output noise as 1 to 5% peak
to peak typical with no mention of measurement bandwidth.
The HP converters achieve 50 mV peak to peak typical and
are fully specified and tested to a wide bandwidth of 0-20 MHz.
Optional input filtering (-FT models) reduces reflected
ripple noise and is similarly low and also fully specified for
typical values (exact value depends on input voltage range).
Typical RMS noise over a 10 kHz to 1 MHz bandwidth is
specified for the input.
Full overload protection is provided by independent pulse-
by-pulse current limiting or with the optional over-temperature
shutdown circuit (-FT models). These protection features
assure you that our HP triple will provide you with zero failure
rate operation.
Five sided shielding is standard along with specified
operation over the full industrial temperature range of -40 to
+90 C case temperature.
Applying The Input
Figure 1 shows the recommended input connections for the
HP Triple DC/DC converter. A fuse is recommended to protect
the input circuit and should not be omitted. The fuse serves to
prevent unlimited current from flowing in the case of a
catastrophic system failure.
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20 Watt HP Triple Series DC/DC Converters
2401 Stanwell Drive Concord, California 94520 Ph: 925/687-4411 or 800/542-3355 Fax: 925/687-3333 www.calex.com Email: sales@calex.com
4
3/2001, eco# 041007-1
Very Low Noise Input Circuit
Figure 2 shows a very low noise input circuit that may be used
with the -FT option converters. This circuit will reduce the input
reflected ripple current by approximately 30 dB over the
standard -FT option filter.
Suggested Capacitor Sources
These capacitors may be used at the input of the standard
model only, see the filtered Input option section for more
information when using the filtered input converter.
Suitable capacitors can be acquired from the following
sources:
United Chemi-Con SXE, RXC, RZ and RZA Series
Suggested Part:
SXE100VB221M12.5X35LL
220F, 100V, 105C Rated
ESR=0.087 Ohms
Allowable Ripple=1.04 A @ 105C
Nichicon
PR and PF
Suggested Part:
UPR100102MPHRH
1000F, 100V, 105C Rated
ESR=0.047 Ohms
Allowable Ripple=1.32 A @ 105C
Panasonic
HFE Series
Suggested Part:
ECEA2AFE221L
220F, 100V, 105C Rated
ESR=0.089 Ohms
Allowable Ripple=1.04 A @ 105C
Remote ON/OFF Pin Option
The optional remote ON/OFF pin may be left floating if this
function is not used. The equivalent input circuit for the ON/
OFF pin is shown in figure 3. The best way to drive this pin is
with an open collector/drain or relay contact. See our application
note titled "Understanding the remote ON/OFF function" for
more information about using the remote ON/OFF pin.
When the ON/OFF pin is pulled low with respect to the -
Input, the converter is placed in a low power drain state. The
ON/OFF pin turns the converter off while keeping the input
bulk capacitor fully charged, this prevents the large inrush
current spike that occurs when the +input pin is opened and
closed.
The ON/OFF pin should never be pulled more that 0.3 volts
below the -input or have a voltage of greater than +8 volts
applied to it.
Figure 3.
The simplified schematic of the HP Triple series ON/OFF pin. The
input impedance is approximately 20k ohms. By leaving this pin
floating the converter will be in the ON state. When the pin is pulled
below 0.7 volt (with respect to the -Input pin) the converter is placed
in the power down or OFF state. See our application note on the
remote ON/OFF function for more information.
L1 = 2H
C1, 2 = 10F / 100V, ALUMINUM
Figure 1.
Standard connections for the HP triple input. The ON/OFF pin may
be left floating if it is not used (-FT option only). The input protection
fuse should not be omitted. If desired, an external transient protection
diode (D1) can be used at the input. See "Applying the input" for
suggestions regarding C1. See the CALEX application notes for
more information on fuses.
When using the standard model, be sure that the impedance
at the input to the converter is less than 0.09 ohms at the
switching frequency. If the converter is located more than
about 1 inch from the input source an added capacitor may be
required directly at the input pins for proper operation.
Suitable capacitors for use at the input of the converter are
given at the end of this section.
-FT Filtered Input Option
The -FT or filtered input option has an internal LC filter that
greatly reduces input reflected ripple current. This option is
useful when the lowest noise or highest power density is
required on your system.
With the filtered input option no external capacitance on
the input is required for most applications, in fact it can
degrade the converters performance. Extremely low ESR
capacitors (< 0.5 ohms) should not be used at the input as this
will cause peaking of the input filters transfer function and
actually degrade the filters performance.
Any stray line inductance effects that cause ringing at the
converters input pins can be damped adequately with a 10 to
100 F / 100 V, low cost, 0.5 to 5 ohm ESR, aluminum
electrolytic capacitor. Normal RF bypass capacitors in the
1000 pF to 0.01 F range may be used without harm.
Figure 2.
This circuit may be used with the -FT option to reduce the reflected
ripple current by approximately 30 dB. The filter must be built close
to the converter for maximum effectiveness. All grounds should be
routed directly to the -input pin.
A
20 Watt HP Triple Series DC/DC Converters
2401 Stanwell Drive Concord, California 94520 Ph: 925/687-4411 or 800/542-3355 Fax: 925/687-3333 www.calex.com Email: sales@calex.com
5
3/2001, eco# 041007-1
Applying The Output
Figure 4 shows typical output connections for the HP Triple In
most applications no external output capacitance will be
necessary. Only your normal 1 to 10 F tantalum and 0.001
to 0.1 F ceramic bypass capacitors sprinkled around your
circuit as needed locally are required. Do not add extra output
capacitance and cost to your circuit "Just Because".
If you feel you must add external output capacitance, do
not use the lowest ESR, biggest value capacitor that you can
find! This can only lead to reduced system performance or
oscillation. See our application note "Understanding Output
Impedance For Optimum Decoupling" for more information.
Figure 4.
The HP triple should be connected to your load as shown. All of the
ground return currents should be returned directly to CMN pin. If
desired, external transient protection diodes can be used.
Ultra Low Noise Output Circuit
The circuit shown in figure 5 can be used to reduce the output
noise to below 10 mV P-P over a 20 MHz bandwidth. Size
inductor L1 appropriately for the maximum expected load
current. All of the ground connections must be as short as
possible back to the CMN pin. The filter should be placed as
close to the HP triple as possible, even if your load is at some
distance from the converter.
Figure 5.
For very low output noise applications this circuit will reduce the
output noise to less than 10 mV P-P over a 0-20 MHz bandwidth. Be
sure to size L1 appropriately for the maximum expected load current
on the 5 volt output.
Operation With Very Light Loads
The HP Triple uses a technique called "Magnetically Coupled
Cross Regulation" to provide the best regulation available
with a single PWM regulator circuit. This scheme works very
well when all loads are operated within 25% to 100% of their
rated load range. When the loads become very unbalanced
(i.e. one or more outputs at no load and the others at full load)
the PWM can have difficulty trying to determine the best
output voltage. The best situation is to keep the minimum load
at 25% for each output and avoid operating any output
unloaded.
The regulation of the HP triple may be improved by using
dummy load resistors to keep the static output power above
about 2 watts (check the exact value required by your circuit).
The load may be balanced by adding a dummy load on the
most lightly loaded outputs, the exact value will depend on
your exact circuit requirements. This minimum load should
not be required to be greater than 25% of each outputs full
load value for quite good regulation.
Dynamic response of the HP triple will degrade when the
unit is operated with less than 25% of full rated power.
If large load excursions or operation with very large load
unbalances are required then a "Dual Loop" converter such as
the CALEX XC triple may provide better performance in your
circuit.
Thermal Overload Protection Option
The -FT option provides a thermal overload circuit that will
protect the converter against overtemperature faults. The
thermal overload circuit works by shutting the PWM circuit
OFF when the case temperature exceeds about 105 C.
When the case cools the converter will automatically restart.
The thermal overload circuit will prevent the converter from
being damaged under the following conditions,
Operation at abnormally high ambient temperatures.
Most long term short circuit conditions.
This option is useful in applications that require the utmost
reliability in unattended operation or where cooling system
failures must not cause permanent damage.
Grounding
The input and output sections are fully floating from each
other. They may be operated fully floating or with a common
ground. If the input and output sections are connected either
directly at the converter or at some remote location from the
converter it is suggested that a 3.3 to 10 F, 0.5 to 5 ohm ESR
capacitor bypass be used directly at the converters output
pins. These capacitors prevent any common mode switching
currents from showing up at the converters output as normal
mode output noise. See "Applying the Output" for more
information on selecting output capacitors.
Also see the CALEX application note "Dealing With
Common Mode Noise" for more information on using common
grounds.
C1 = 1F / 35V TANTALUM
C2 = 10F / 16V TANTALUM
C3 = 0.01F / 100V CERAMIC
FL1 = PANASONIC EXC-EMT103DT EMI FILTER
L1
= 5F / 2.5 AMP INDUCTOR
A
20 Watt HP Triple Series DC/DC Converters
2401 Stanwell Drive Concord, California 94520 Ph: 925/687-4411 or 800/542-3355 Fax: 925/687-3333 www.calex.com Email: sales@calex.com
6
3/2001, eco# 041007-1
Case Grounding
The copper case serves not only as a heat sink but also as a
EMI shield. The 0.017 inch thick case provides >25 dB of
absorption loss to both electric and magnetic fields at 220
kHz, while at the same time providing 20 to 40 % better heat
sinking over competitive thin steel, aluminum or plastic designs.
The case shield is tied to the -input pin. This connection is
shown on the block diagram. The case is floating from the
output sections. The input is coupled to the outputs only by the
low 400 pF of isolation capacitance. This low I/O capacitance
insures that any AC common mode noise on the inputs is not
coupled to your output circuits.
Compare this isolation to the more usual 1000 - 2000 pF
found on competitive designs and you will see that CALEX
provides the very best DC and AC isolation available. After all,
you are buying an isolated DC/DC to cut ground loops. Don't
let the isolation capacitance add them back in.
Temperature Derating
The HP Triple series can operate up to 90C case temperature
without derating. Case temperature may be roughly calculated
from ambient by knowing that the HP Triples case temperature
rise is approximately 9.5C per package watt dissipated.
For example: If a 24T HP converter is outputting 15 watts,
at what ambient could it expect to run with no moving air and
no extra heatsinking?
Efficiency of a 24T is approximately 84% at 15 watts of
output power, this leads to an input power of about 18 watts.
The case temperature rise would be 18 - 15 watts or 3 watts
9.5 = 29C. This number is subtracted from the maximum
case temperature of 90C to get: 61C.
This example calculation is for an HP triple without any
extra heat sinking or appreciable air flow. Both of these factors
can greatly affect the maximum ambient temperature (see
below). Exact efficiency depends on input line and load
conditions, check the efficiency curves for exact information.
This is a rough approximation to the maximum ambient
temperature. Because of the difficulty of defining ambient
temperature and the possibility that the loads dissipation may
actually increase the local ambient temperature significantly,
these calculations should be verified by actual measurement
before committing to a production design.
Remember, it is the users responsibility to be sure that the
case temperature of the HP Triple does not exceed 90C for
maximum reliability in operation.
Typical Performance (Tc=25C, Vin=Nom VDC, Rated Load).
0
2
4
6
8
10
12
14
16
18
LINE INPUT (VOLTS)
0.0
0.7
1.4
2.1
2.8
3.5
INPUT CURRENT (AMPS)
12 VOLT INPUT CURRENT Vs. LINE INPUT VOLTAGE
100% LOAD
50% LOAD
0
10
20
30
40
50
60
70
80
LINE INPUT (VOLTS)
0.0
0.2
0.4
0.6
0.8
1.0
INPUT CURRENT (AMPS)
48 VOLT INPUT CURRENT Vs. LINE INPUT VOLTAGE
100% LOAD
50% LOAD
0
10
20
30
40
50
60
70
80
90
100
LOAD (%)
65
70
75
80
85
90
EFFICIENCY (%)
12 VOLT EFFICIENCY Vs. LOAD
LINE = 9VDC
LINE = 12VDC
LINE = 18VDC
0
10
20
30
40
50
60
70
80
90
100
LOAD (%)
65
70
75
80
85
90
EFFICIENCY (%)
48 VOLT EFFICIENCY Vs. LOAD
LINE = 36VDC
LINE = 48VDC
LINE = 72VDC
9
10
11
12
13
14
15
16
17
18
LINE INPUT(VOLTS)
65
70
75
80
85
EFFICIENCY(%)
12 VOLT EFFICIENCY Vs. LINE INPUT VOLTAGE
100% FULL LOAD
50% FULL LOAD
36
40
44
48
52
56
60
64
68
72
LINE INPUT(VOLTS)
60
65
70
75
80
85
90
EFFICIENCY(%)
48 VOLT EFFICIENCY Vs. LINE INPUT VOLTAGE
100% FULL LOAD
50% FULL LOAD
0
4
8
12
16
20
24
28
32
36
LINE INPUT (VOLTS)
0.0
0.5
1.0
1.5
2.0
INPUT CURRENT (AMPS)
24 VOLT INPUT CURRENT Vs. LINE INPUT VOLTAGE
100% LOAD
50% LOAD
18
20
22
24
26
28
30
32
34
36
LINE INPUT(VOLTS)
70
75
80
85
90
EFFICIENCY(%)
24 VOLT EFFICIENCY Vs. LINE INPUT VOLTAGE
100% FULL LOAD
50% FULL LOAD
0
10
20
30
40
50
60
70
80
90
100
LOAD (%)
65
70
75
80
85
90
EFFICIENCY (%)
24 VOLT EFFICIENCY Vs. LOAD
LINE = 18VDC
LINE = 24VDC
LINE = 36VDC
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