TECHNICAL DATASHEET
Rev. C
FA12S48-250
250W DC-DC Converter
10-36 Vdc Input
48Vdc Output at 5.2A
Full-Brick Package
Features:
88% Efficient at Full Load
90% Efficiency at 1/2 Load
Fast Transient Response
Operation to No Load
Output Trim ±10%
Remote ON/OFF (Active High/Low)
Remote Sense Compensation
Delivers a Continuous 100W at 25°C
with No Air / No Heatsink
Description:
Very Low Output Ripple
Fixed Switching Frequency
Output Over Current Foldback
Output Short Circuit Protection
Over Temperature Protection
1500 V Isolation
100% Burn In
Synchronizable
The FA series is a high-density full brick converter that incorporates the desired features required
in today’s demanding low voltage bus applications. Its unique dual interleaved phase-shifted
topology minimizes both input and output noise. When performance, reliability, and low cost are
needed, the FA series delivers.
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Technical Specifications
SPECIFICATION
Switching Frequency
INPUT (V
in
)
Operating Voltage Range
UVLO Turn On at
UVLO Turn Off at
UVLO Hysterisis
Maximum Input Current
(Graph 3)
No Load Input Current
(Graph 3)
Input Current under “Remote Off”
Reflected Ripple Current
Input Surge Voltage
EFFICIENCY
(Graph 1)
OUTPUT (V
o
)
Voltage Set Point
Voltage Adjustment
(Table1)
Load Regulation
Line Regulation
Temperature Drift
Remote Sense Compensation
Ripple
(Photo4,5,6)
Spikes
(Photo 4,5,6)
Current
Current Limit
Over Voltage Limit
DYNAMIC RESPONSE
Load step /
V
(Photo7)
Recovery Time
(Photo 7)
Turn On Delay
(Photo 1)
Turn On Overshoot
(Photo 1,2)
Hold Up Time
(Photo 3)
REMOTE ON/OFF
Remote ON – Positive logic
Remote OFF – Positive logic
Remote ON pin Floating - Positive logic
I
ON/OFF
Sink current - Positive logic
Remote ON – Negative logic
Remote OFF – Negative logic
Remote ON/OFF pin Floating – Negative logic
I
ON/OFF
Sink to pull low – Negative logic
I
ON/OFF
Source to drive high – Active High or Low
Turn On Delay –
(Photo 2)
Turn Off Delay –
(Photo 3)
ISOLATION
Input-Output
Isolation Resistance
Isolation Capacitance
THERMAL
Ambient
(Graph 2)
Over Temperature Protection
Storage Temperature
MTBF
MECHANICAL
Weight
±Sense shorted to ±Vout
Max Output limited to 300W
±Sense shorted to ±Vout
±Sense shorted to ±Vout
TECHNICAL DATASHEET
Rev C
FA12S48-250
Model No. FA12S48-250
Related condition
Min
-
10
9.5
9.0
-
-
-
-
-
-
-
47.52
-1%
43.2
-10%
-
-
-
-
-
-
0
-
54
50% to 100% Io
Recovery to within 1% Nominal Vout
From Vin (min) to Vout (nom)
Full Load Resistive
All specifications are based on 25°C, Nominal Input Voltage, and Maximum Output Current unless otherwise noted.
We reserve the right to change specifications based on technological advances.
Nom
600
12
9.7
9.25
0.5
29.4
0.10
1
20
-
85
48.00
Max
-
36
10
9.5
-
-
-
-
-
50
-
48.48
+1%
52.8
+10%
0.2
0.2
0.02
1
480
480
5.2
-
66
-
-
-
-
-
5.0
2.0
5.0
1.0
2.0
5.0
4.7
1
1
-
10
-
-
-
Unit
KHZ
Vdc
Vdc
Vdc
Vdc
A
A
mA
mA
Vdc
%
Vdc
%
Vdc
%
%
% / °C
Vdc
mV p-p
mV p-p
A
A
Vdc
V
mS
mS
%
mS
Vdc
Vdc
Vdc
mA
Vdc
Vdc
mA
µA
mS
µS
Vdc
GΩ
µF
°C
°C
°C
Hours
g
Low Line
No Load
With L-C filter as shown in Fig. 7.
100 mS
Io=5.2A
0.05
0.05
0.01
-
50
50
-
6.8
60
Max Output limited to 300W
(max. drop in each + and – output trace)
0.1µF Ceramic & 10µF Tantalum
0.1µF Ceramic & 10µF Tantalum
Rated maximum output current
Power Limited-Dependent upon SENSE compensation
and TRIM adjustment
-
1
-
0.4
-
50
-
0.0
0
-
Active High or Active Low (See page 14 for ordering details)
TTL high or Open-circuit
2.5
-
TTL Low
-
-
Over Operating Voltage Range
4.4
-
V
ON/OFF
=0V, Vin=75V
-
-
Max Low to Enable
-
-
Min High to Disable
2.5
-
Over Operating Voltage Range
4.4
-
V
ON/OFF
=0V, Vin=75V
-
-
-
-
Enabled
-
6
Disabled
-
-
1 minute
1500
1
-
-40
-
-55
-
-
0.010
Max. Ambient limited by Derating Curves (Graph 2)
Self Resetting
Ambient
Calculated Using Bellcore TR-332 Method 1 case 3
-
Graph 2
25
110
-
-
125
2,212,456
See Figure 1
318
-
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WALL INDUSTRIES, INC.
Figure 1: Mechanical Dimensions
Unit: inches [mm]
TECHNICAL DATASHEET
Rev C
FA12S48-250
HEATSINK SUPPLIED ATTACHED WITH
THERMAL INTERFACE MATERIAL.
HEATSINK HAS Ø.120 ±.005 Ø3.05±0.13 THRU HOLE 6X
.84±.04 [21.3±1.0]
.02 [0.4] 6X REF
COVER TO STANDOFF
HEATSINK
TO STANDOFFS ONLY
SEE NOTE 5
.000 [0.00]
.20 MIN [5.1 MIN]
SEE NOTE-1&3
PIN LENGTH FROM
STANDOFFS ONLY
.015 [0.38]
.02 [0.4] 6X REF
COVER TO STANDOFF
STANDARD
.50+.03 12.7 +0.8
-.00
-0.0
TO STANDOFFS ONLY
.000 [0.00]
.20 MIN [5.1 MIN]
SEE NOTE-1&3
PIN LENGTH FROM
STANDOFFS ONLY
.30 [7.6]
LABEL
.30+.02 7.6+0.5
-.03
-0.6
SERIAL NO:
DOT DENOTES
PIN-1
DC/DC CONVERTER
3.600 [91.44]
1.800 [45.72]
SEE NOTE-4
.50 [12.7]
.35 [8.9]
1
2
3
4
5
8
9
6
2.100 [53.34]
.000 [0.00]
EXETER, NH 03833
MODEL NAME
.400 [10.16]
.700 [17.78]
1.000 [25.40]
1.400 [35.56]
7
WALL INDUSTRIES
XXXX
DATE CODE
4.60 +.02 117.0+0.5
-.03
-0.8
.20±.03 [5.1±0.8]
4.200 [106.68]
2.40+.02 61.0+0.5
-.03
-0.8
R
NONMETALLIC INSULATOR 2X
PIN DESIGNATION
1
+OUT
2
+SENSE
3
TRIM
4
-SENSE
5
-OUT
6
+IN
7
SD
8
SYNC
9
-IN
PIN Ø
Ø.081 [2.06]
Ø.040 [1.02]
Ø.040 [1.02]
Ø.040 [1.02]
Ø.081 [2.06]
Ø.081 [2.06]
Ø.040 [1.02]
Ø.040 [1.02]
Ø.081 [2.06]
NOTES:
1. PIN TO PIN TOLERANCE ± .01 [±0.3],
PIN DIAMETER TOLERANCE: ±.005 [±0.13].
2. CASE MATERIAL: .040 [1.02] THICK, ALUMINUM ALLOY 3003-0,
PER: QQA 250/2.
3. UNLESS OTHERWISE SPECIFIED.
TO ORDER:
4. UNIT COMES WITH EITHER 3M x 0.5 THREADED
THRU INSERTS OR FOR Ø.125 THRU-HOLE ADD:
“TH” SUFFIX TO MODEL PART NUMBER.
EXAMPLE: FA12S5-300TH
5. FOR HEAT SINK ADD: “HS” SUFFIX TO MODEL
PART NUMBER. EXAMPLE: FA12S5-300HS.
6. OPTIONAL CHASSIS MOUNT VERSION
AVAILABLE (SEE CMFA SERIES).
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Page 3 of 14
WALL INDUSTRIES, INC.
DESIGN CONSIDERATIONS
Under Voltage Lock Out (UVLO)
TECHNICAL DATASHEET
Rev C
FA12S48-250
The converter output is disabled until the input voltage exceeds the UVLO turn-on limit. The converter will remain ON until the input
voltage falls below the UVLO turn-off limit. There is approximately 0.5V hysteresis in the UVLO circuit.
Over Current Protection
The converter is internally protected from short circuit and over current conditions. During these fault conditions, the converter output
will “hiccup”- (short) or “fold back” - (over current). The converter output will recover once the short or over current fault is removed.
Over Temperature Protection
The converter is protected from over temperature conditions. Upon exceeding this temperature, the converter will shut down. The
converter will automatically recover once it has sufficiently cooled.
Input Filter
A 1,000µF low ESR capacitor across the input pins is recommended for most system level designs. No additional input capacitance is
needed for the power supply to operate with low impedance inputs. However, most “real world” system level integration will have some
amount of trace or wiring lengths – raising the inductive impedance. The added input capacitor will bring the impedance back towards
unity.
Output Filter
No additional output capacitor is needed for the power supply to operate within stated specifications. However, if it is a requirement to
reduce the ripple and noise on the output, additional capacitance may be added. Usually, ceramic MLCC’s capacitor works best for
reducing H.F. spike noise. Also, capacitance in the form of a tantalum or aluminum electrolytic capacitor may also be placed across the
output in order reduce base ripple, and improve the load transient peak-to-peak voltage deviation.
Remote Sense
To improve the voltage regulation at the load, route the connections from the -Sense and the +Sense pins to the –Vout and +Vout
connections AT the load. This will force the converter to regulate the voltage at the load and not at the pins of the converter. If it is not
desired to use the Remotes Sense feature, the –Sense and +Sense pins should be connected to the -Vout and +Vout pins respectively.
Fusing
It is required that the input to the converter be supplied with a maximum 50 A, 250 V rated fuse.
Safety
The FA series is CE pending and pending approval of the following: UL1950, CUL950, TUV60950 FILE 155800. The isolation
provided by the FA Series is a Basic insulation in accordance with EN60950. SELV output reliability is maintained only if the input to
the FA converter is an SELV source.
Remote ON/OFF
The FA Series has Remote ON/OFF (Enable/Disable) capability using TTL logic levels. This function is offered as either
Active=TTL High (no suffix) or Active=TTL Low (R suffix), see order details on page 14. For Remote ON/OFF limits, see page 2.
Figure 2. Remote (L/E)
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WALL INDUSTRIES, INC.
Synchronization
TECHNICAL DATASHEET
Rev C
FA12S48-250
The FA series provides synchronization of switching frequencies between multiple FA series power supplies. The synchronization
function is accomplished without the need for any added external circuitry. By tying the SYNC pin between FA modules, they will all
automatically synchronize. If synchronization is not used, the pin should be tied to –Vin.
Output Voltage Trim
The following information is provided to allow quick calculation of the trim resistor value for a desired output voltage. The general
procedure for calculating a trim resistor is as follows:
1.
2.
3.
4.
Determine the desired output voltage deviation %.
To trim down, solve for resistor value using the “Rtlow” equation.
To trim up, solve for resistor value using the “Rthi” equation.
Solved resistor values are in KΩ.
Figure 3
510
10.2
Rtlow
½
%
Figure 4
5.1
Vo (100
%) 510
Rthi
½
10.2
%
1.2225
%
Notes:
1.
2.
3.
4.
5.
Maximum trim range is ±10%. This includes remote sense drops if applicable.
Output current is limited to specified current when trimming down.
Output power is limited to specified power when trimming up.
Trim resistors should be placed close to the module.
If the trim function is not used, it is advised to leave the trim pin floating / not connected.
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