TAURUS Series
48V Input, 1.5V, 1.8V, 2.0V, 2.5V, 3.3VDC, 40A Output
or 5.0VDC, 30A Output
The Taurus half brick is the first
CoolConverter
™
in the Galaxy family of
high-efficiency DC/DC converters.
Industry Standard Pinout and Footprint
Typical Efficiency:
93% at 3.3V, 20A; 91% at 3.3V, 40A
No Heat Sink Required
Very Low Common-mode Noise for a
Commercial DC/DC Converter
Two-stage Input Filter
Constant Switching Frequency
Remote Sense
Single Board Design
Optional Baseplate or Low Profile Heatsink
for Improved Thermal Performance
Header with M3 Metal Inserts for Mechanical
Connection to PCB
Two Year Warranty
The open-frame Taurus is available with an
optional baseplate or low profile heatsink.
Control Functions
Uses Patented Power Supply Control
and Architecture
Microprocessor Controlled
Primary-side Enable, Choice of Logic
Protection Features
Over Temperature Protection
Over Voltage Protection
Over/Under Input Voltage Protection
Over Current Protection
Typical Characteristics
Output Setpoint Accuracy:
±1%
Load Regulation:
±0.25%
Line Regulation:
±0.25%
Regulation over Line, Load, and Temperature:
±2%
Low Output Ripple
Output Trim
Taurus Series, Page 1
WWW.GALAXYPWR.COM
Part No. 99–001 Rev. 5.0–090803
General Specifications
V
IN
= 48V
DC
, T
A
@25
°
C, 300 LFM airflow, V
OUT
= 3.3V, I
OUT
= Full Load unless otherwise noted.
Available output power depends on ambient temperature and good thermal management. (See application graphs for limits.)
Input Characteristics
Parameter
Min
Typ
Max
Units
Operating Input Voltage
Input Current (Model Dependent)
Input Capacitance
Input Hysteresis, Low Line
36
48
4.4
2
75
6.5
V
DC
A
µF
V
DC
%V
NOM
mV
RMS
mV
P–P
A
A
A
mV
µS
mS
%V
OUT
%V
OUT
%V
OUT
V
DC
MΩ
Output Characteristics
Regulation Over Line, Load & Temperature
Voltage Ripple
Voltage Ripple, 20MHz BW
Current Range
Current Limit Inception
Short Circuit Current, Peak (see Note below)
Output Transient Response, 50% to 75% load change, 1A/µsec
Settling Time to
±1%
Turn-on Time to 98% Vnom
Output Overshoot at Turn-on
Trim Range
Overvoltage Protection, Latching
98
102
15
50
40
48
50
125
300
30
1
110
130
2000
10
117
200
0
41
90
Isolation
Isolation Test Voltage, Input/Output (Basic)
Isolation Resistance
Features
Overtemperature Protection, Thermal Sensor, Latching*
Switching Frequency, Fixed
°C
kHz
Notes: During short circuit, converter will shut down and attempt to restart once per second.
The average current during this condition will be very low and the device can be safely left in this condition
continuously. For specific output voltage specifications, see the corresponding detailed data sheet.
*PCB less than 130
°
C.
General Specifications
Operating Temperature
Storage Temperature
Relative Humidity
Vibration
Material Flammability
Weight
MTBF
Telcordia (Bellcore)
-40°C to +100°C
–55°C to +125°C
10% to 95% RH,
Non-condensing
2 to 9Hz, 3mm disp.,
9 to 200Hz 1g
UL V-0
55 grams
1,600,000 hours
Approvals and Standards
UL and c-UL Recognized Component,
TUV, UL60950, CSA 22.2 No. 950,
IEC/EN60950**
EMC Characteristics:
Designed to meet emission and immunity
requirements per EN55022, CISPR22,
Class B and CISPR24.
** An external fuse shall be used to comply with the requirements.
Taurus Series, Page 2
WWW.GALAXYPWR.COM
Part No. 99–001 Rev. 5.0–090803
Application Notes
CoolConverter
™
Family
Galaxy’s
C
OOL
C
ONVERTER
™
Family features:
• Patented single-stage power conversion architecture, control,
and magnetic design allow unprecedented power density and
efficiency in an isolated power supply.
• An advanced microcontroller reduces parts count while
adding features, performance, and flexibility in the design.
• Low common-mode noise as a result of lower capacitance in
the transformer compared to planar magnetics and metal
baseplate designs.
• Higher reliability than planar transformer designs that can
suffer from via fatigue from thermal cycling, and metal
baseplate designs with board to board interconnects that are
subject to mechanical stress on electrical connections.
Protection and Control
Valid Input Voltage Range:
The converter measures the input voltage and will
not allow operation outside of the input voltage
specification. As shown by the graphs, hysteresis is
added to both the high and low voltage to prevent
the converter from turning on and off repeatedly
when the voltage is held near either voltage
extreme. At low line this assures the maximum
input current is not exceeded; at high line this
assures the semiconductor devices in the converter
are not damaged by excessive voltage stress.
ON/OFF Logic Option:
The ON/OFF control logic can be either Negative
(standard) or Positive to enable the converter. For
Negative logic, the ON/OFF pin is brought below
1.0V with respect to the –INPUT pin to enable the
converter. The pull-down must be able to sink
100µA. For Positive logic, the ON/OFF pin is
brought to greater than 4.0V with respect to the
–INPUT pin and be limited to less than 10V. To
request the Positive logic version, add the suffix (P)
to the standard part number. The ON/OFF pin has a
built-in pull-up resistor of approximately 100kΩ to
+5V.
48Vin: 30
24Vin: 15
32
16
34
17
36
18
38
19
40
20
48Vin: 70
24Vin: 35
72
36
74
37
76
38
78
39
80
40
Taurus Series, Page 3
WWW.GALAXYPWR.COM
Part No. 99–001 Rev. 5.0–090803
APPLICATION NOTES
Output Over Voltage Protection:
The output voltage is constantly monitored by the
microprocessor and a redundant secondary side
crowbar circuit that is set to a higher trip point than
the microprocessor protection. If the output voltage
exceeds the over-voltage specification, the
microprocessor will latch the converter off. To turn
the converter on requires either cycling the ON/
OFF pin or power to the converter. This advanced
feature prevents the converter from damaging the
load if there is a converter failure or application
error. If non-latching is required, consult factory.
Thermal Shutdown:
The printed circuit board temperature is measured
using a semiconductor sensor. If the maximum
rated temperature is exceeded, the converter is
latched off. To re-enable the converter requires
cycling the ON/OFF pin or power to the converter.
If non-latching shutdown is required, consult
factory.
Control Options:
As the behavior of the circuit is determined by
firmware in the microcontroller, specific customer
requirements such as:
• non-latching thermal protection
• custom valid input voltage range
• controlled delay from initiating an ON/OFF
signal for power sequencing
can be accomplished with no change to hardware.
The standard behavior was chosen based on
system design experience but we understand that
customers often have their own requirements.
Please consult Galaxy Power for your special
needs.
Remote Sense:
The output voltage is regulated at the point where
the sense pins connect to the power output pins.
Total sense compensation should not exceed 0.4V
or 10% of Vout, whichever is greater.
Safety:
An external input fuse must always be used to
meet these safety requirements.
R
TRIM-DOWN
=
Trim:
To trim the output voltage higher, connect the
required trim resistor from the Trim pin to the
+Sense pin. To trim the output voltage lower,
connect the required trim resistor from the Trim pin
to the –Sense pin. See diagram below.
Trim-down
Trim-down (%)
{
100
– 2 kΩ
∆%
}
Trim-up (for 3.3V)
Trim-up (%)
R
TRIM-UP
=
{
Vo (100+∆%) (100+2∆%)
–
1.225∆%
∆%
}
kΩ
External Output Trimming
+ Sense
Trim
– Sense
Taurus Series, Page 4
WWW.GALAXYPWR.COM
Part No. 99–001 Rev. 5.0–090803
GPTW3V340 OPERATION
Efficiency
100
98
96
Power Dissipation
94
92
90
88
86
84
82
80
0
10
20
30
40
Power Dissipation (W)
Efficiency (%)
36V Vin
48V Vin
75V Vin
36V Vin
48V Vin
75V Vin
Load Current (A)
Load Current (A)
Transient Response
Voltage Ripple
V
OUT
V
OUT
20
I
OUT
10
Start-up Waveform
T
Thermal Derating Curves
40
Ch2 +Over
1.212%
35
30
25
Ch2 High
3.26V
2
Ch2 Max
3.30V
Iout (A)
20
300 LFM, Low Profile Heat Sink
15
10
200 LFM, Low Profile Heat Sink
300 LFM, Metal Plate
200 LFM, Metal Plate
300 LFM, Open Frame
200 LFM, Open Frame
1
5
0
0
Ch1
5.00mV
B
W
Ch2
1.00 V
BW
M 4.00ms A
Ch1
2.60V
10
20
30
40
50
60
70
Ambient Air Temperature (deg C)
Taurus Series, Page 5
WWW.GALAXYPWR.COM
Part No. 99–001 Rev. 5.0–090803
