Pisces II Series, Page 1
WWW.GALAXYPWR.COM
Part No. 02-007 Rev. 3.0061004
The Pisces II Series is the industry's
first 60A quarter brick in Galaxy Power's
CoolConverter
TM
line of high-efficiency DC/DC
converters.
Industry Standard Pinout and Footprint
Typical Efficiency:
93% at 2.5V, 30A; 91% at 2.5V, 60A
Very Low Dissipation
No Heat Sink Required
Low Profile, 0.38"
Very Low Common-mode Noise for a
Commercial DC/DC Converter
Two-stage Input Filter
Constant Switching Frequency
Remote Sense, Wide Trim Range
Single Board Design, Very Low Parts Count
Optional Baseplate or Low Profile Heatsink
for Improved Thermal Performance
Header with M3 Metal Inserts for Mechanical
Connection to PCB
Two Year Warranty
PISCES II Series
Control Functions
Patented Power Supply Control and Architecture
Microprocessor Controlled
Primary-side Enable, Choice of Logic
Protection Features
Over Temperature Protection
Over Voltage Protection
Over Current Protection
Over/Under Input Voltage Protection
Typical Characteristics
Output Setpoint Accuracy:
1%
Load Regulation:
0.2%
Line Regulation:
0.2%
Regulation over Line, Load, and Temperature:
2%
Low Output Ripple
Output Trim
The open-frame Pisces II is available with an optional
heat-spreading baseplate or low profile heatsink for
use in extremely demanding applications.
ISO 9001 CERTIFIED ORGANISATION
48V or 24V Input
1.0V, 1.2V, 1.5V, 1.8V, 2.0V, 2.5VDC, 60A Output
3.3V, 45A; 5.0V, 30A Output
Pisces II Series, Page 2
WWW.GALAXYPWR.COM
Part No. 02-007 Rev. 3.0061004
General Specifications
Operating Temperature
-40
C to +100C
Storage Temperature
-55
C to +125C
Relative Humidity
10% to 95% RH,
Non-condensing
Vibration
2 to 9Hz, 3mm disp.,
9 to 200Hz 1g
Material Flammability
UL V-0
Weight
35 grams
MTBF
Telcordia (Bellcore)
1.6 Million Hours
General Specifications
V
IN
= 48V
DC
, T
A
@25
C, 300 LFM Airflow, V
OUT
=2.5V, 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
(24V Input in [brackets])
Parameter
Min
Typ
Max
Units
Operating Input Voltage
36 [18]
48 [24]
75 [36]
V
DC
Input Current (Model Dependent)
6 [10]
A
Input Capacitance
4 [9]
F
Input Hysteresis, Low Line
2 [1]
V
DC
Output Characteristics
Regulation Over Line, Load & Temperature
98
102
%V
NOM
Voltage Ripple
25
mV
RMS
Voltage Ripple, 20MHz BW
85
mV
PP
Current Range
0
60
A
Current Limit Inception
103
140
%I
OUT
Short Circuit Current, Peak (see Note below)
90
A
Output Transient Response, 50% to 75% load change, 1A/
sec
5
%V
OUT
Settling Time to
1%
200
S
Turn-on Time to 98%Vnom
35
mS
Output Overshoot at Turn-on
0
%V
OUT
Trim Range
70
110
%V
OUT
Overvoltage Protection, Latching
130
%V
OUT
Isolation
Isolation Test Voltage, Input/Output (Basic)
2250
V
DC
Isolation Test Voltage, Input/Case
2000
V
DC
Isolation Test Voltage, Output/Case
500
V
DC
Isolation Resistance
10
M
Features
Overtemperature Protection, Thermal Sensor, Latching*
110
C
Switching Frequency, Fixed
250
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
Approvals and Standards
UL and c-UL Recognized Component, TUV,
UL60950, CSA 22.2 No. 950, IEC/EN 60950
EMC Characteristics:
Designed to meet emission and immunity
requirements per EN55022, CISPR 22, Class B,
and CISPR 24.
An external fuse shall be used to comply with the
requirements.
Pisces II Series, Page 3
WWW.GALAXYPWR.COM
Part No. 02-007 Rev. 3.0061004
Undervoltage Lockout
30
32
36
34
40
38
Input Voltage (V)
Input Curr
ent
Voltage
Rising
Voltage
Falling
Overvoltage Lockout
75
76
78
77
80
79
Input Voltage (V)
Input Curr
ent
Voltage
Rising
Voltage
Falling
CoolConverter
TM
Galaxy's proprietary CoolConverter
TM
provides:
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 from balanced winding design.
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, bring the ON/OFF pin to less than 1.0V
with respect to the INPUT pin to enable the converter.
The pull-down must be able to sink 100
A. For
Positive logic, bring the ON/OFF pin 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
100k
to +5V.
Application Notes
Pisces II Series, Page 4
WWW.GALAXYPWR.COM
Part No. 02-007 Rev. 3.0061004
Output Over Voltage Protection:
The output voltage is constantly monitored by the
microprocessor with a redundant secondary-side
measurement circuit that both shuts down the duty cycle
and triggers the microprocessor to shut down. 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 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.
External Output Trimming
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. The Trim-down equation applies to all Voltages.
Application Notes
R
TRIM-UP
=
Vo (100+
%)
-
(100+
2%)
5.11k
1.225%
%
{
}
Trim-up
(for 3.3V)
+ Sense
Trim
Sense
R
TRIM-DOWN
=
100
2
5.11k
%
{ }
Trim-down
Trim-down (%)
R
TRIM-UP
=
Vo (100+
%)
-
(100+
2%)
5.11k
0.62%
%
{
}
Trim-up for 1.5V and above:
Trim-up for less than 1.5V:
Trim-down for all voltages:
Pisces II Series, Page 5
WWW.GALAXYPWR.COM
Part No. 02-007 Rev. 3.0061004
Pisces II Operation
2.5
2.0
1.5
1.0
0.5
0
6
4
2
0
Vout
Enable
0 10 20 30 40 50
Time (mS)
Vout (V)
Enable (V)
Enable-on Waveform
48V Input, 30A, 1.8V Output
Power Dissipation
1.8V Output
14
12
10
8
6
4
2
0
0
20
40
50
60
Load Current (A)
Power Dissipation (W)
36V Vin
48V Vin
60V Vin
10
30
Power Dissipation
2.5V Output
16
14
12
10
8
6
4
2
0
0
20
40
50
60
Load Current (A)
Power Dissipation (W)
36V Vin
48V Vin
60V Vin
10
30
Efficiency
1.8V Output
94
92
90
88
86
84
82
80
0
20
40
60
50
Output Current (A)
Ef
ficiency (%)
36V Vin
48V Vin
60V Vin
30
10
Efficiency
2.5V Output
94
92
90
88
86
84
82
80
0
20
40
60
50
Output Current (A)
Ef
ficiency (%)
36V Vin
48V Vin
60V Vin
30
10
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