![](http://datasheet.mmic.net.cn/170000/SQM48T20012-NBAT_datasheet_9789771/SQM48T20012-NBAT_20.png)
MCD10208 Rev. 1.0, 08-Jul-10
Page 20 of 33
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SQM48T/S20 DC-DC Converter Data Sheet
36-75 VDC Input; 1.2-3.3 VDC @ 20A Outputs
Electrical Specifications: SQM48T/S20018 (1.8 Volt Out)
Conditions: TA=25 C, 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
20 ADC, 1.8 VDC Out @ 36 VDC In
1.2
ADC
Input Stand-by Current
Vin = 48V, converter disabled
3
mADC
Input No Load Current (0 load on the output)
Vin = 48V, converter enabled
30
mADC
Input Reflected-Ripple Current
25 MHz bandwidth
6
mAPK-PK
Input Voltage Ripple Rejection
120 Hz
TBD
dB
Output Characteristics
Output Voltage Set Point (no load)
-40 C to 85 C
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
2
1.773
1.827
VDC
Output Ripple and Noise - 25 MHz
bandwidth
Full load + 10 μF tantalum + 1 μF
ceramic
30
50
mVPK-PK
External Load Capacitance
Plus full load (resistive)
20,000
μF
Output Current Range
0
20
ADC
Current Limit Inception
Non-latching
21
24
27.5
ADC
Peak Short-Circuit Current
Non-latching. Short=10m.
30
44
A
RMS Short-Circuit Current
Non-latching
6.7
Arms
Dynamic Response
Load Change 25% of Iout Max, di/dt = 0.1A/μs Co = 1 μF ceramic
80
mV
di/dt = 5A/μs
Co = 450 μF POS + 1 μF ceramic
140
mV
Settling Time to 1%
100
s
Efficiency
100% Load
86
%
50% Load
88
%
Additional Notes: 2. -40 C to 85 C.
Ambient Temperature [°C]
20
30
40
50
60
70
80
90
Lo
ad
Cur
rent
[A
dc]
0
5
10
15
20
25
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 SQM48T20018 converter
with D height pins mounted vertically with air flowing from
pin 3 to pin 1, MOSFET temperature
120 C, Vin = 48 V.
Load Current [Adc]
0
5
10
15
20
25
E
ffici
enc
y
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/S20018 converter mounted vertically with air
flowing from pin 3 to pin 1 at a rate of 300 LFM (1.5 m/s) and
Ta = 25
C.