TECHNICAL SPECIFICATIONS
(T
A
=25°C, airflow rate=300 LFM, V
in
=48Vdc, nominal Vout unless otherwise noted; mounted on board.)
PARAMETER
NOTES and CONDITIONS Q48SR1R840NR A
Min. Typ. Max. Units
ABSOLUTE MAXIMUM RATINGS
Input Voltage
Continuous
80 Vdc
Transient (100ms) 100ms 100 Vdc
Operating Temperature Refer to Figure 24 for the measuring point -40 114 °C
Storage Temperature
-55 125 °C
Input/Output Isolation Voltage 1 minute 1500 Vdc
INPUT CHARACTERISTICS
Operating Input Voltage
36 48 75 Vdc
Input Under-Voltage Lockout
Turn-On Voltage Threshold
33 34 35 Vdc
Turn-Off Voltage Threshold
31 32 33 Vdc
Lockout Hysteresis Voltage
1 2 3 Vdc
Maximum Input Current 100% Load, 36Vin 2.7 A
No-Load Input Current 50 100 mA
Off Converter Input Current 10 20 mA
Inrush Current(I
2
t) 0.03 A
2
S
Input Reflected-Ripple Current P-P thru 12µH inductor, 5Hz to 20MHz 20 mA
Input Voltage Ripple Rejection 120 Hz 70
dB
OUTPUT CHARACTERISTICS
Output Voltage Set Point Vin=48V, Io=Io.max, Ta=25C 1.75 1.8 1.85
Vdc
Output Voltage Regulation
Over Load Io=Io,min to Io,max ±2 ±5 mV
Over Line Vin=36V to 75V ±2 ±5 mV
Over Temperature Ta=-40C to 85C ±30 ±100 mV
Total Output Voltage Range over sample load, line and temperature 1.69 1.91 V
Output Voltage Ripple and Noise 5Hz to 20MHz bandwidth
Peak-to-Peak Full Load, 1µF ceramic, 10µF tantalum 20 100 mV
RMS Full Load, 1µF ceramic, 10µF tantalum 10 20 mV
Operating Output Current Range 0 40 A
Output DC Current-Limit Inception Output Voltage 10% Low 105 130 %
DYNAMIC CHARACTERISTICS
Output Voltage Current Transient 48V, 10µF Tan & 1µF Ceramic load cap, 0.1A/µs
Positive Step Change in Output Current 50% Io,max to 75% Io,max 50 150 mV
Negative Step Change in Output Current 75% Io,max to 50% Io,max 50 150 mV
Settling Time (within 1% Vout nominal) 100 uS
Turn-On Transient
Start-Up Time, From On/Off Control 15 30 mS
Start-Up Time, From Input 15 30
mS
Maximum Output Capacitance Full load; 5% overshoot of Vout at startup 20000 µF
EFFICIENCY
100% Load
87 %
60% Load 88.5 %
ISOLATION CHARACTERISTICS
Input to Output 1500 Vdc
Isolation Resistance 10 MΩ
Isolation Capacitance 2000 pF
FEATURE CHARACTERISTICS
Switching Frequency 260 kHz
ON/OFF Control, (Logic Low-Module ON)
Logic Low Von/off at Ion/off=1.0mA 0 0.8 V
Logic High Von/off at Ion/off=0.0 µA 15 V
ON/OFF Current Ion/off at Von/off=0.0V 1 mA
Leakage Current Logic High, Von/off=15V 50 uA
Output Voltage Trim Range Across Pins 9 & 5, Pout <= max rated powe
0.8 1.9 V
Output Voltage Remote Sense Range Pout <= max rated power 10 %
Output Over-Voltage Protection Over full temp range; % of nominal Vout 115 130 145 %
GENERAL SPECIFICATIONS
MTBF Io=80% of Io, max; Ta=25°C, airflow rate=300 LFM 2.3 M hours
Weight 32 32 grams grams
Over-Temperature Shutdown Refer to Figure 24 for the measuring point 125 °C
2
