TECHNICAL SPECIFICATIONS
(T
A
=25°C, V
in
=48Vdc, nominal Vout unless otherwise noted.)
DS_F48SA28025_12072007
2
PARAMETER NOTES and CONDITIONS F48SA28025 (Standard)
Min. Typ. Max. Units
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Continuous 80 Vdc
Transient (100ms) 100ms 100 Vdc
Operating Temperature Please refer to Fig 20 for measuring point -40 95 °C
Storage Temperature -55 125 °C
Input/Output Isolation Voltage 2250 Vdc
INPUT CHARACTERISTICS
Operating Input Voltage 36 48 75 Vdc
Input Under-Voltage Lockout
Turn-On Voltage Threshold 33 34.5 36 Vdc
Turn-Off Voltage Threshold 31 32.5 34 Vdc
Lockout Hysteresis Voltage
2 Vdc
Input Over-Voltage Lockout
Turn-On Voltage Threshold 76 78 80 Vdc
Turn-Off Voltage Threshold 78 80 82 Vdc
Lockout Hysteresis Voltage 2 Vdc
Maximum Input Current 100% Load, 36Vin 23 A
Inrush Current(I
2
t) 1 A
2
s
Input Reflected-Ripple Current P-P thru 15µH inductor, 5Hz to 20MHz 20 mA
Input Voltage Ripple Rejection 120 Hz 50 dB
OUTPUT CHARACTERISTICS
Output Voltage Set Point Vin=48V, Io=Io.max, Tc=25°C 27.44 28.00 28.56
Vdc
Output Voltage Regulation
Over Load Io=Io,min to Io,max 28 56 mV
Over Line Vin=36V to 75V 28 56 mV
Over Temperature Tc=-40°C to 100°C 100 300 mV
Total Output Voltage Range over all load, line and temperature 27.25 28.00 28.75 V
Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth
Peak-to-Peak Full Load, 1µF ceramic, 10µF Low ESR cap 200 mV
RMS Full Load, 1µF ceramic, 10µF Low ESR cap 65 mV
Operating Output Current Range 2 25 A
Output DC Current-Limit Inception Output Voltage 10% Low 120 150 %
DYNAMIC CHARACTERISTICS
Output Voltage Current Transient
48V, Tested with a 10µF, a 1µF Ceramic cap and a
470uF low ESR aluminum load cap,
ΔIo/Δt=1A/µs
Positive Step Change in Output Current 50% Io.max to 75% Io.max 450 mV
Negative Step Change in Output Current 75% Io.max to 50% Io.max 450 mV
Settling Time (within 1% Vout nominal) 500 us
Turn-On Transient
Start-Up Time, From On/Off Control 20 35 ms
Start-Up Time, From Input 20 35
ms
Output Capacitive Load 470 6000 µF
EFFICIENCY
100% Load
91.5 %
60% Load 91.5 %
ISOLATION CHARACTERISTICS
Input to Output 2250 Vdc
Input to Case
1500 Vdc
Output to Case 1500 Vdc
Isolation Resistance 10 MΩ
Isolation Capacitance 1800 pF
FEATURE CHARACTERISTICS
Switching Frequency 300 kHz
t
t
v
r
h
t V
lt
rin
t
rt
Power good pin max applied voltage Max sink current 5mA 35 V
Auxiliary output voltage
Aux pin source current <=20mA
Referenced to Sense(-) pin
7 10 13 V
Output Voltage Trim Range
Pout ≦ max rated power
-15 +10 %
Output Voltage Remote Sense Range
Pout ≦ max rated power
0.5 V
Output Over-Voltage Protection Over full temp range; % of nominal Vout 115 140 %
GENERAL SPECIFICATIONS
MTBF Io=80% of Io, max; Ta=25°C 1.14 M hours
Weight 168 grams
Over-Temperature Shutdown Please refer to Fig.20 for measuring point 100 °C
