15 Watt TC Single Series DC/DC Converters
Features
-40° to +90°C Case Operating
Range Standard
Dual Stage Output Filter for Low Noise Operation
Very Low OFF Current, 1 mA Typically
Water Washable Design
Five Year Warranty
Description
These single output DC/DC converters are designed to provide
a wide range of PCB mount power solutions. The extra wide
3:1 input voltage range covers the common American and
European telecom standards along with 24 volt industrial
control applications.
For flexibility, a trim pin is included to adjust the output
voltage. Use it to compensate for voltage drops in your
system’s wiring or to achieve non standard voltages. Use the
remote ON/OFF function to maximize battery life.
The TC Single Series continues the CALEX tradition of
reliable design by including transient overvoltage suppressor
diode protection at the input and output terminals. Also
provided as standard are overcurrent protection circuits.
These features assure zero failure rate operation when using
the TC Single Series.
MODEL
*48S5.3000TC
48S12.1250TC
48S15.1000TC
Selection Chart
INPUT RANGE
VDC
MIN
20
20
20
MAX
60
60
60
OUTPUT
VDC
5.0
12.0
15.0
OUTPUT
mA
3000
1250
1000
* Agency Approval: UL 1459
15 Watt TC Single Series Block Diagram
SHIELDED
ISOLATION TRANSFORMER
A
4 + OUTPUT
+ INPUT 3
-INPUT 2
CURRENT
MODE
PWM
5 CMN
6 TRIM
ON/OFF 1
ISOLATED
FEEDBACK
FIVE-SIDED SHIELDED COPPER CASE
LOW TC
BANDGAP REFERENCE
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
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eco# 041007-1
15 Watt TC Single Series DC/DC Converters
Input Parameters*
Model
Voltage Range
Input Current Full Load
No Load
Efficiency
Switching Frequency
Maximum Input Overvoltage, 100ms
No Damage
Turn-on Time, 1% Output Error
Recommended Fuse
MIN
TYP
MAX
TYP
TYP
TYP
TYP
MAX
TYP
5
(1)
48S5.3000TC
48S12.1250TC
20.0
48.0
60.0
380
4
82
120
75
10
48S15.1000TC
Units
VDC
375
4
83
mA
%
kHz
VDC
ms
395
2
79
Output Parameters*
Model
Output Voltage
Rated Load (3)
Voltage Range
100% Load
Load Regulation
25-100% Full Load
Line Regulation
Vin = Min-Max VDC
Short Term Stability (4)
Long Term Stability
Transient Response (5)
Dynamic Response (6)
Input Ripple Rejection (7)
Noise, 0-20MHz bw (2)
RMS Noise
Temperature Coefficient
Short Circuit Protection to
Common for all Outputs
MIN
MAX
MIN
TYP
MAX
TYP
MAX
TYP
MAX
TYP
TYP
TYP
TYP
TYP
TYP
TYP
TYP
MAX
75
3
100
150
48S5.3000TC
5
0
3000
4.950
5.000
5.050
0.5
0.75
0.1
0.15
48S12.1250TC
12
0
1250
11.900
12.000
12.100
0.1
0.2
0.01
0.1
< 0.02
< 0.05
600
200
> 60
60
2
50
150
Current Limit
60
2
200
170
48S15.1000TC
15
0
1000
14.900
15.000
15.100
0.1
0.2
0.01
0.1
Units
VDC
mA
VDC
%
%
%/24Hrs
%/kHrs
µs
mV peak
dB
mV P-P
mV RMS
ppm/°C
NOTES
*
(1)
(2)
(3)
(4)
All Parameters measured at Tc=25°C, 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.
See our application note for picking the correct fuse size.
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 0.1µF, ceramic capacitor
located 1 inch away from the converter.
Minimum load required for rated regulation only. Dynamic
response may degrade if run at less than 25% full load.
Short term stability is specified after a 30 minute warm-up at full
load, and with constant line, load and ambient conditions.
(5)
The transient response is specified as the time required to settle
from a 50 to 75% step load change (rise time of step = 2µSec)
to a 1% error band.
(6) Dynamic response is the peak overshoot voltage during the
transient response time defined in note 5.
(7) The input ripple rejection is specified for DC to 120Hz ripple with
a modulation amplitude of 1% Vin.
(8) The ON/OFF pin is Open Collector TTL, CMOS, and relay
compatible. The input to this pin is referenced to Pin 2 (-Input)
and is protected to +75VDC.
(9) Case is tied to Pin 3, +Input.
(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.
A
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
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eco# 041007-1
15 Watt TC Single Series DC/DC Converters
General Specifications*
All Models
ON/OFF Function (8)
ON Logic Level
or Leave Pin Open
OFF Logic Level
Input Resistance
Converter Idle Current,
ON/OFF Pin Low
Isolation (9)
Isolation Voltage
10µA Leakage
Input-Output
Input to Output
Capacitance
Output Trim Function
Input Resistance
Programming Range
Environmental
Case Operating Range
No Derating
Storage Range
Thermal Impedance (10)
General
Unit Weight
Chassis Mounting Kit
TYP
2
MS8
oz
Units
MIN
MAX
TYP
TYP
8.0
2.0
100
<1
VDC
VDC
kohms
mA
MIN
TYP
700
300
VDC
pF
BOTTOM VIEW
SIDE VIEW
Mechanical tolerances unless otherwise noted:
X.XX dimensions: ±0.020 inches
X.XXX dimensions: ±0.005 inches
Seal around terminals is not hermetic. Do not immerse units in any
liquid.
TYP
MIN
MIN
MAX
MIN
MAX
TYP
20
±5
-40
90
-55
100
10
kohms
%
°C
°C
°C/Watt
Pin
1
2
3
4
5
6
Function
ON/OFF
-INPUT
+INPUT
+OUTPUT
CMN
TRIM
15 Watt TC Single Typical Application
Figure 1 shows the recommended connections for the 15 Watt
TC Singles. Capacitor C1 is required for proper operation (see
below). The trim and ON/OFF pins can be safely left floating
if they are not used. The input fuse should not be omitted.
The fuse serves two purposes:
1) It prevents unlimited current from flowing in the case of a
catastrophic system failure
2) UL regulations for telecom equipment require the use of a
fuse. See CALEX Application Notes for more info on sizing
the input fuse.
SIZE TRACES FOR 1 AMP DC MAXIMUM
FUSE
TO INPUT
SOURCE
A
SIZE TRACES
APPROPRIATELY FOR
LOAD REQUIREMENTS
3 + INPUT
C1
2 - INPUT
+ OUTPUT 4
LOAD
CMN 5
*
1 ON/OFF
TRIM 6
*
*
PINS 1 AND 6 MAY BE LEFT
FLOATING IF NOT USED
FIGURE 1.
Recommended application circuit for TC Single Series
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
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eco# 041007-1
15 Watt TC Single Series DC/DC Converters
Sizing The Input Capacitor
For maximum reliability the TC Single Series must use a
capacitor of sufficient ripple handling capability connected
across the input pins. The probable result of undersizing (over
stressing) this capacitor is increased self heating, shortening
of the capacitors and hence shortening of your systems’ life.
Oversizing the capacitor can have a negative effect on your
product’s cost and size, although this kind of overdesign does
not result in shorter life of any components. There is no one
optimum value for this capacitor. The size and capacity are
dependent on the following factors:
1) expected ambient temperature and your temperature
derating guidelines
2) your ripple current derating guidelines
3) the maximum load expected on the converter
4) the minimum input voltage expected on the converter
5) the statistical probability that your system will spend a
significant amount of time at any worst case extreme
Factors 1 and 2 are determined by your system design
guidelines. These can range from 50% to 100% of the
manufacturer’s rated maximum, although a usual derating
factor is 70% of manufacturer’s maximum limit. 70% derating
means that if the capacitor manufacturer says their capacitor
can do 1 A RMS and 100 VDC you would not use the part over
700 mA RMS and 70 VDC. Surge voltage rating should also
be evaluated against any expected voltage surges when
selecting a capacitor working voltage.
Factors 3 and 4 realistically determine the worst case ripple
current. The reflected ripple current increases with output
load and increases as the input voltage decreases. So if you
are running with a solid 48 VDC input and at 50% load your
capacitors required ripple current rating would decrease by
more than 2:1 from what would be required for operation at 20
VDC with full load (see the “Input Reflected Ripple” curve).
Factor 5 is not easy to quantify. At CALEX, we can make
no assumptions about a customer’s system so we design for
continuous operation at worst case extremes.
=
I=
Solution
According to the 15 Watt TC Single Series “Reflected Input
Ripple vs. Line Input” curve at 40 VDC input and 2.25 Amps
output (75% of rated load), the reflected input ripple can be
read as 650 mA RMS. From the derating guidelines the
capacitor’s rated voltage and ripple current can be determined.
Capacitor voltage rating is calculated as:
1
V=
x
Maximum Expected Input
Voltage Derating Factor
V=
1
x 52 = 74
Volts or greater
0.7
1
x
Reflected Ripple
Current Derating Factor
1
0.7
x 650
mA
= 0.93
A RMS or greater at 45°C
(40°C ambient + 5°C for self heating)
A capacitor selection can now be made. Look only at
controlled low ESR types (where the ESR is specified as a
maximum) because these usually have the highest ripple
current capability per unit volume.
Be careful to compare apples to apples. Some
manufacturers specify their capacitors at 85°C and others
specify at 105°C. The manufacturers give temperature derating
guidelines, so all capacitors should be normalized to your
maximum ambient (plus 5°C to account for self heating)
before making a selection. Since the 15 Watt TC Single Series
operates at 120 kHz the frequency usually does not have to
be derated since most modern low ESR capacitors are rated
at 100 kHz.
One note: The temperature derating multipliers are based
on the capacitor’s expected life at 105°C. The life of a
capacitor operating at a significantly lower temperature will
not be greater if the ripple current in the part is increased over
the 105°C rating. This means that a capacitor rated for 1 A
RMS current at 105°C and 2 A RMS at 50°C will have the same
life if used at either point while the same capacitor used at 1
A RMS and 50°C will have a longer life.
Example Of Capacitor Sizing
Given the following conditions, select the minimum size
capacitor needed to provide reliable performance:
Converter ......................................... 48S5.3000TC
Minimum Input Voltage .................... 40 VDC
Maximum Input Voltage ................... 52 VDC
Maximum Load ................................ 2.25 Amps
Maximum Ambient Temperature ..... 40°C
Your Capacitor Voltage
Derating Guideline ........................... 70% of Maximum
Specification
Your Capacitor Current
Derating Guideline ........................... 70% of Maximum
Specification
Nichicon
Suggested Part:
A
Suggested Capacitor Sources
Suitable capacitors can be acquired from the following sources:
United Chemi-Con
Suggested Part:
SXE, RXC, RZ and RZA Series
SXE100VB221M12.5X35LL
220µF, 100V, 105°C Rated
ESR=0.087 ohms
Allowable Ripple=1.45 A @ 105°C
PR and PF
UPR2A102MPH
1000µF, 100V, 105°C Rated
ESR=0.047 ohms
Allowable Ripple=1.32 A @ 105°C
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
eco# 041007-1
15 Watt TC Single Series DC/DC Converters
Panasonic
Suggested Part:
HFE Series
ECEA2AFE221L
220µF, 100V, 105°C Rated
ESR=0.089 ohms
Allowable Ripple=1.04 A @ 105°C
Use one resistor for either trim up or trim down. The values
can range from infinity to zero ohms with zero ohms providing
the most trim.
USING TRIMPOT
+ OUT
4
TRIM
CMN
The suggested capacitors will work for any line and load
condition, however, they may be oversized for your application.
Low Noise Input Filtering Circuit
To reduce the input reflected ripple to less than 50 mA peak
to peak the circuit shown in Figure 2 may be used. Toroid core
inductors have theoretically lower radiated noise than a rod
core. Use reasonable caution when selecting an inductor
other than the one specified. Nearly any 105°C rated capacitor
can be used for the 10µF / 100V part. To prevent input filter
peaking the ESR should be in the range of 0.5 to 2 ohms. Do
not use the lowest ESR capacitor available for this part. This
will render the filter ineffective.
THIS CAPACITOR IS REQUIRED
FOR PROPER OPERATION
6
5
10 K
LOAD
USING FIXED RESISTORS
+ OUT
4
TRIM
6
CMN
TRIM
DOWN
TRIM
UP
LOAD
5
FUSE
50 µH, 1000 mA
3 + INPUT
Figure 3.
Output trim methods
TO INPUT
SOURCE
10 µF
100 V
2 - INPUT
Temperature Derating Guidelines
Care must be taken in the application of all power devices. Be
sure to account for the self heating in your instrument due to
the power converter and the loads. For minimum temperature
gradient, the hottest components should be mounted at the
bottom of your system (bottom of a vertical PCB) and the
coolest components at the top of the system. This will help to
even the temperature of the entire system and prevent
temperature gradients.
The 15 Watt TC Single Series has a thermal impedance of
10°C per package watt dissipated. During normal operation
the 15 Watt TC Single Series can be expected to run at 80%
efficiency at 48 VDC and full load. This means that the 15 Watt
TC Single Series is dissipating nearly 4 Watts internally at full
load. This, therefore, translates to a package temperature rise
of about 40°C (10°C/watt x 4 watts dissipated).
FIGURE 2.
Low noise input filter circuit
Remote ON/OFF Circuit Operation
The remote ON/OFF pin is best applied as follows:
To turn the unit off, the ON/OFF pin should be tied to the -
Input pin. This is best done by an open collector arrangement
or contact closure.
To turn the unit on, let the ON/OFF pin float.
If the remote ON/OFF pin is not used, it may be safely left
floating. There is a 100K internal pull-up resistor inside the
unit to +9 volts DC.
Other applications of the ON/OFF function can be found in
the application note, “Understanding the Remote ON/OFF
Function”.
A
The maximum rated case temperature for the 15 Watt TC
Series is 90°C. This means that, in the absence of other heat
sources (including the load that the converter is powering)
and with at least 3 inches of clearance, the 15 Watt TC Single
Series can be expected to operate at an ambient of 50°C.
Additional heat sinks or cooling air flow can extend the
ambient temperature of operation significantly.
Proper Application Of The Trim Pin
The trim pin is used to adjust the output voltage slightly to
compensate for voltage drops in the system’s wiring. Figure
3 shows the proper application of the trim pin. Either a 10K
trimpot or fixed resistors may be used.
Other applications for the TRIM function can be found in the
CALEX application note: “Applying the Remote Sense and
Trim Functions on 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
eco# 041007-1
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