Data Sheet
August 2000
Titania™ Power Modules
Austin Series Non-Isolated SMT DC-DC Power Modules:
3.3 Vdc and 5.0 Vdc Input, 1.5 Vdc to 3.3 Vdc Output, 6A
Features
•
•
•
•
•
•
300A/µs load transient response
Small size and very low profile
Minimal space on printed circuit board
Nominal dimensions: 44.6 mm x 12.7 mm x
5.46 mm (1.756 in. x .500 in. x .214 in.)
High reliability: 200 FITs/5 million hour MTBF
High efficiency
•
3.3 V
IN
•
86% typical @ 2.5V, 6 A
•
75% typical @ 1.5V, 6A
•
5 V
IN
•
85% typical @ 3.3V, 6A
•
73% typical @ 1.8V, 6A
Single control pin for margining and on/off
control
Overcurrent foldback
Thermal shutdown
No external bias required
Low inductance surface-mount connections
Parallelable
†
UL*
1950 recognized,
CSA
C22.2 No. 950-95
Certified, and VDE 0805 Licensed
The Austin Power Module Series provides
precise voltage and fast transient response in
the industry’s smallest footprint while offering
very high reliability and high efficiency.
•
Applications
•
•
•
•
•
•
•
•
•
Workstations
Servers
Desktop computers
DSP applications
Distributed power architectures
Telecommunications equipment
Adapter cards
LAN/WAN applications
Data processing applications
•
•
•
•
•
•
Description
The Austin Power Module Series is designed to
meet the precise voltage and fast transient
requirements of today’s high performance DSP
and microprocessor circuits and system board
level applications. Advanced circuit techniques,
high-frequency switching, custom passive and
active components, and very high-density,
surface-mount packaging technology deliver high-
quality, ultra compact, DC-DC conversion.
*
UL
is a registered trademark of Underwriters Laboratories,
Inc.
†
CSA
is a registered trademark of Canadian Standards
Association.
1
Lucent Technologies Inc.
Austin Series Non Isolated SMT DC-DC Power Modules:
3.3 Vdc and 5.0 Vdc Input, 1.5 Vdc to 3.3 Vdc Output, 6A
Data Sheet
August 2000
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These
are absolute 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. Input voltage range of
V
IN
= 3.0 V — 3.6V is listed as 3.3 V
IN
and input voltage range of V
IN
= 4.5V — 5.5V is listed as 5.0 V
IN
.
Table 1. Absolute Maximum Ratings
Parameter
Input Voltage (continuous)
Forced Output Voltage
OUTEN/ADJ Terminal Voltage
Storage Temperature
Device
3.3 V
IN
5.0 V
IN
All
All
All
Symbol
V
IN
V
IN
V
OF
V
OUTEN/ADJ
T
A/STG
Min
– 0.3
– 0.3
– 0.3
– 0.3
– 40
Max
4.5
6.5
6.0
2.0
150
Unit
Vdc
Vdc
Vdc
Vdc
°C
Electrical Specifications
Table 2. Input Specifications
Parameter
Operating Input Voltage
Input Ripple Rejection (120 Hz)
Operating Input Current
•
•
•
(0A < I
OUT
< 5A)
(3.0V < V
IN
< 3.6V)
(4.5V < V
IN
< 5.5V)
(3.0V < V
IN
< 5.5V)
3.3 V
IN
5.0 V
IN
All
I
IN
I
IN
I
Q
—
—
—
—
—
15
5.5
5.0
—
A
A
mA
Device
3.3 V
IN
5.0 V
IN
Symbol
V
IN
V
IN
Min
3.0
4.5
Typical
3.3
5.0
50
Max
3.6
5.5
Unit
V
V
dB
Quiescent Input Current (I
OUT
= 0)
Fusing Considerations
CAUTION: This power module is not internally fused. An input line fuse must always be used.
This 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 fusing 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 10A (see Safety
and Reliability Specifications).
Lucent Technologies Inc.
2
Data Sheet
August 2000
Austin Series Non Isolated SMT DC-DC Power Modules:
3.3 Vdc and 5.0 Vdc Input, 1.5 Vdc to 3.3 Vdc Output, 6A
Output Control
The control pin is a dual-function port that serves to enable/disable the converter or provide a means of
adjusting the output voltage over a prescribed range. When the control pin is grounded, the converter is
disabled. With the pin left open, the converter regulates to its specified output voltage. For any other
voltage applied to the pin, the output voltage follows this relationship:
V
CONTROL
V
OUT
=
1.5V
* V
OUT nom
The Thevenin equivalent input resistance of the control pin is approximately 7.68K ohms and the open
circuit voltage is 1.5V.
The equation to margin low by connecting a resistor from the control pin to ground is:
V
OUT
/
V
OUT nom
R
LOW
= 7.68K
1 – V
OUT
/
V
OUT nom
To margin low by 5%, R
LOW
= 146K.
The equation to margin high by connecting a resistor, R
HIGH
, from the control pin to the input voltage, V
IN
is:
7.68K
R
HIGH
=
V
OUT
/
V
OUT nom
– 1
1.5
V
IN
–1
– 7.68K
To maintain high of 5%, R
HIGH
= 351K for V
IN
= 5 volts and R
HIGH
= 177K for V
IN
= 3.3 volts. Trim resistor
tolerance will obviously affect output voltage. To determine the magnitude of this effect, simply use the
extreme values in the above equations.
Because trimming affects the system reference, trimming beyond +/- 10% is unacceptable and +/-
approximately 5% is desirable. One affect trimming has, aside from output voltage adjustment, is
changing the current limit inception point. Trimming the unit down beyond 5% requires derating available
current by 1% for every percent beyond 5 that the module is trimmed down. For example, if a module is
trimmed down 7%, then output current would have to be derated 2%. If paralleled modules are to be
trimmed using the control pin, divide the calculated trim resistance for a single unit by the number of
modules paralleled. For example, if two paralleled units are to be trimmed 5% low, then a resistance of
146K divided by 2 should be used.
3
Lucent Technologies Inc.
Austin Series Non Isolated SMT DC-DC Power Modules:
3.3 Vdc and 5.0 Vdc Input, 1.5 Vdc to 3.3 Vdc Output, 6A
Data Sheet
August 2000
Output Regulation
These modules have intentional output resistance to facilitate transient response and paralleling. This
means that output voltage will decrease with increasing output current. For this reason, the total DC
regulation window at a given operating and ambient temperature is comprised of a no load setpoint and a
voltage drop due to module output resistance. Regulation data provided in Table 3 includes both initial
setpoint and voltage drop. Because Table 3 includes output resistance drop, the maximum column is
always a no load condition and the minimum column is always a full load condition. No module could pass
production test with a full load regulation point equal to the maximum column. This means that at any
operating current, the regulation will always be better than the total window specified in Table 3.
Table 3. Output Specifications
Parameter
Output voltage
These specifications are under
all specified input voltage, load
current, and temperature
conditions. They do not
include ripple or transient.
Output current
Output ripple
(See Figure 10)
Device
3.3V
2.5V
2.0V
1.8V
1.5V
—
3.3 V
IN
5.0 V
IN
Symbol
V
OUT
V
OUT
V
OUT
V
OUT
V
OUT
I
OUT
V
RIPPLE
V
RIPPLE
Min
3.200
2.425
1.940
1.746
1.455
0
—
—
Typical
3.3
2.5
2.0
1.8
1.5
—
—
—
Max
3.400
2.575
2.060
1.854
1.545
6.0
80
100
Unit
V
V
V
V
V
A
mV
p-p
mV
p-p
Static Voltage Regulation
The output voltage measured at the converter output pins on the system board will be within the range
shown in Table 3, except for input voltage turn-on and turn-off. Static voltage regulation includes:
•
DC output initial voltage
•
Input voltage range
•
3.0V — 3.6V
•
4.5V — 5.5V
•
Load regulation from 0A — 6A
Output Ripple and Noise
Ripple and noise are defined as periodic or random signals at the output pins under constant load. Typical
full load output ripple and noise waveforms are shown in Figures 12 — 20.
Lucent Technologies Inc.
4
Data Sheet
August 2000
Austin Series Non Isolated SMT DC-DC Power Modules:
3.3 Vdc and 5.0 Vdc Input, 1.5 Vdc to 3.3 Vdc Output, 6A
Output Overcurrent Protection/Overtemperature Protection
Current limiting is provided for momentary overloads and short circuits. A sustained overload may cause
the thermal shutdown circuit to activate. The current limit inception is nominally 7 amperes with the power
semiconductors at rated temperature in a 25 °C ambient environment. The thermal circuitry will shut down
the module at 115 °C minimum on the power semiconductors’ top surfaces.
Input/Output Decoupling
An input capacitance of 100
µF,
with an ESR of less than 100 milliohms, and at least 1
µF
ceramic or
equivalent is recommended for the input to the modules. The 100
µF
should always be used unless
main bulk buss capacitors are located close to the module. This capacitor provides decoupling in the
event of a fault to the module output. Input voltage should never go below 2.5 volts or internal protection
circuitry may fail to act. To achieve noise levels shown in Figures 11 – 20, one 100
µF
tantalum
capacitor and two 1
µF
ceramic capacitors were used. 0.75 inches of 0.14 inch wide track (with no
ground beneath) was used as an inductor between the input pin of the module and the decoupling
capacitors (see Figure 10). An impedance vs. frequency plot has been provided for the 100
µF
capacitor
to aid in selecting equivalent parts.
Output decoupling used to achieve noise levels shown in Figures 11 – 20 was 1
µF
in series with 0.5Ω
and .01
µF.
Ringing on the output due to common impedance with the input decoupling circuit was
damped using the 1
µF/0.5Ω
series combination. An equivalent damping network is recommended.
Care should be taken that selected output decoupling capacitors do not form troublesome L-C resonant
networks with track inductance. Austin Power Modules may be used with up to 10,000
µF
of
capacitance. The modules are designed to remain stable with any capacitor/ESR combination.
Figure 10. Input/Output Decoupling Circuit
5
Lucent Technologies Inc.
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