2
Lucent Technologies Inc.
Data Sheet
May 2000
dc-dc Converters; 36 to 75 Vdc Input, 3.3 Vdc Output; 33 W to 50 W
QW050F1 and QW075F1 Power Modules:
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are abso-
lute stress ratings only. Functional operation of the device is not implied at these or any other conditions in excess
of those given in the operations sections of the data sheet. Exposure to absolute maximum ratings for extended
periods can adversely affect device reliability.
Electrical Specifications
Unless otherwise indicated, specifications apply over all operating input voltage, resistive load, and temperature
conditions.
Table 1. Input Specifications
Fusing Considerations
CAUTION: This power module is not internally fused. An input line fuse must always be used.
This encapsulated power module can be used in a wide variety of applications, ranging from simple stand-alone
operation to an integrated part of a sophisticated power architecture. To preserve maximum flexibility, internal fus-
ing is not included; however, to achieve maximum safety and system protection, always use an input line fuse. The
safety agencies require a normal-blow fuse with a maximum rating of 3 A (see Safety Considerations section).
Based on the information provided in this data sheet on inrush energy and maximum dc input current, the same
type of fuse with a lower rating can be used. Refer to the fuse manufacturer’s data for further information.
Parameter
Symbol
Min
Max
Unit
Input Voltage:
Continuous
Transient (100 ms)
Operating Case Temperature
(See Thermal Considerations section.)
Storage Temperature
I/O Isolation Voltage (for 1 minute)
V
I
V
I
,
trans
T
C
—
—
–40
75
100
100
Vdc
V
°C
T
stg
—
–55
—
125
1500
°C
Vdc
Parameter
Symbol
V
I
Min
36
Typ
48
Max
75
Unit
Vdc
Operating Input Voltage
Maximum Input Current
(V
I
= 0 V to 75 V; I
O
= I
O, max
; see Figures 1 and
2):
QW050F1
QW075F1
Inrush Transient
Input Reflected-ripple Current, Peak-to-peak
(5 Hz to 20 MHz, 12 μH source impedance;
see Figure 13.)
Input Ripple Rejection (120 Hz)
I
I, max
I
I, max
i
2
t
I
I
—
—
—
—
—
—
—
10
2.5
3.5
1.3
—
A
A
A
2
s
mAp-p
—
—
60
—
dB