MCD10085 Rev. 1.1, 08-Jul-10 Page 16 of 30 www.power-one.com
SQM48 Series Data Sheet
SemiQ
TM
Family 25A DC-DC Converters
Electrical Specifications: SQM48T/S25018 (1.8 Volts Out)
Conditions: T
A
=25ºC, Airflow=300 LFM (1.5 m/s), Vin=48 Vdc, Vout=1.8 Vdc unless otherwise specified.
PARAMETER NOTES MIN TYP MAX UNITS
INPUT CHARACTERISTICS
Maximum Input Current 25 Adc, 1.8 Vdc Out @ 36 Vdc In 1.45 Adc
Input Stand-by Current
Vin = 48 V, converter disabled 3 mAdc
Input No Load Current (0 load on the output)
Vin = 48 V, converter enabled 30 mAdc
Input Reflected-Ripple Current
25MHz bandwidth 6 mA
PK-PK
Input Voltage Ripple Rejection 120Hz TBD dB
OUTPUT CHARACTERISTICS
Output Voltage Set Point (no load) -40ºC to 85ºC 1.782 1.800 1.818 Vdc
Output Regulation
Over Line ±2 ±4 mV
Over Load ±2 ±5 mV
Output Voltage Range Over line, load and temperature 1.773 1.827 Vdc
Output Ripple and Noise - 25MHz bandwidth Full load + 10 F tantalum + 1 F ceramic 30 50 mV
PK-PK
External Load Capacitance Plus full load (resistive) 20,000 F
Output Current Range 0 25 Adc
Current Limit Inception Non-latching 26.5 30 32 Adc
Peak Short-Circuit Current Non-latching. Short=10m. 35 46 A
RMS Short-Circuit Current Non-latching 6.7 Arms
DYNAMIC RESPONSE
Load Change 20% of Iout Max, di/dt = 0.1 A/S Co = 1 F ceramic 80 mV
di/dt = 5 A/S Co = 450 F tant. + 1 F ceramic 140 mV
Setting Time to 1% 100 µs
EFFICIENCY
100% Load 83 %
50% Load 87 %
Ambient Temperature [°C]
20 30 40 50 60 70 80 90
Load Current [Adc]
0
5
10
15
20
25
30
500 LFM (2.5 m/s)
400 LFM (2.0 m/s)
300 LFM (1.5 m/s)
200 LFM (1.0 m/s)
100 LFM (0.5 m/s)
30 LFM (0.15 m/s)
Fig. 1.8V.1: Available load current vs. ambient air temperature
and airflow rates for SQM48T25018 converter with D height
pins mounted vertically with air flowing from pin 3 to pin 1,
MOSFET temperature 120C, Vin = 48 V.
Load Current [Adc]
0 5 10 15 20 25 30
Efficiency
0.65
0.70
0.75
0.80
0.85
0.90
0.95
72 V
48 V
36 V
Fig. 1.8V.2: Efficiency vs. load current and input voltage for
SQM48T/S25018 converter mounted vertically with air flowing
from pin 3 to pin 1 at a rate of 300 LFM (1.5 m/s) and Ta =
25C.
