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HBD DC-DC Series Applications Note
REV. APR 21, 2004

Page 1 of 62
HBD DC-DC Series
Applications Note












HBD Series


APPLICATIONS
NOTE



















This document contains information describing legacy products
and may list part numbers that are no longer manufactured, cite
product and regulatory agency specifications that have been
superceded, and reference acquired companies whose names are
no longer used commercially. Please contact Technical Support
at Power-One if you have any questions regarding this document.
REV. APR 21, 2004

Page 2 of 62
HBD DC-DC Series
Applications Note

Table of Contents

Topic
Page
GENERAL INFORMATION AND APPLICATIONS ASSISTANCE ........................................................................... 5

I
NTRODUCTION
.......................................................................................................................................................... 5

O
PEN
F
RAME
C
ONSTRUCTION
.................................................................................................................................... 5

D
ESIGN
F
EATURES
..................................................................................................................................................... 5

M
ODELS IN THE
HBD

S
ERIES
..................................................................................................................................... 6

DESIGN CONSIDERATIONS..................................................................................................................................... 7

SAFETY CONSIDERATIONS .................................................................................................................................... 8

I
SOLATION
................................................................................................................................................................. 8

F
USING
..................................................................................................................................................................... 8

SELV

O
UTPUT
.......................................................................................................................................................... 8

C
ASE
G
ROUNDING
..................................................................................................................................................... 9

MINIMUM LOAD REQUIREMENTS........................................................................................................................... 9

10%

(
OF FULL LOAD
)
MINIMUM LOAD REQUIRED ON EACH OUTPUT OF THE
HBD ............................................................ 9

OUTPUT REGULATION OF THE HBD SERIES ....................................................................................................... 9

O
UTPUT
V
OLTAGE
R
EGULATION
................................................................................................................................. 9

O
UTPUT
O
VERLOAD AND
S
HORT
C
IRCUIT
P
ROTECTION
............................................................................................... 9

OUTPUT OVERVOLTAGE PROTECTION .............................................................................................................. 10

TRANSIENT RESPONSE......................................................................................................................................... 10

S
PECIFIED
L
OAD
T
RANSIENT
R
ESPONSE AT
N
OMINAL
L
INE
P
ICTURES
........................................................................ 10

S
PECIFIED
L
OAD
T
RANSIENT
R
ESPONSE AT
L
OW
L
INE
P
ICTURES
............................................................................... 11

S
PECIFIED
L
OAD
T
RANSIENT
R
ESPONSE AT
H
IGH
L
INE
P
ICTURES
.............................................................................. 13

F
IFTY
P
ERCENT
L
OAD
S
TEP
T
RANSIENT
R
ESPONSE AT
N
OMINAL
L
INE
P
ICTURES
........................................................ 14

F
IFTY
P
ERCENT
L
OAD
S
TEP
T
RANSIENT
R
ESPONSE AT
L
OW
L
INE
P
ICTURES
.............................................................. 16

F
IFTY
P
ERCENT
L
OAD
S
TEP
T
RANSIENT
R
ESPONSE AT
H
IGH
L
INE
P
ICTURES
............................................................. 17

LINE TRANSIENT RESPONSE ............................................................................................................................... 18

L
INE
V
OLTAGE
S
TEPPED
U
P
..................................................................................................................................... 19

L
INE
V
OLTAGE
S
TEPPED
D
OWN
................................................................................................................................ 20

EFFICIENCY

AND

HEAT

DISSIPATION............................................................................................................... 21

E
FFICIENCY VS
.

O
UTPUT
L
OADING
............................................................................................................................ 21

COOLING.................................................................................................................................................................. 22

T
ABLE OF
T
HERMAL
R
ESISTANCE VS
.

A
IR
F
LOW
........................................................................................................ 23

COOLING WITH ATTACHED HEAT SINKS ........................................................................................................... 25

C
OOLING WITH
N
ATURAL
C
ONVECTION
..................................................................................................................... 25

C
OOLING WITH
F
ORCED
C
ONVECTION
....................................................................................................................... 26

D
ERATING FOR ALTITUDE
.......................................................................................................................................... 29

THERMAL CALCULATION EXAMPLE ................................................................................................................... 30




REV. APR 21, 2004

Page 3 of 62
HBD DC-DC Series
Applications Note

Table of Contents (Cont.)

Topic
Page
TURN-ON TIME ........................................................................................................................................................ 30

T
URN
-O
N FROM
I
NPUT
V
OLTAGE
,

S
TANDARD
U
NITS
.................................................................................................. 30

T
URN
-O
N FROM
I
NPUT
V
OLTAGE
P
ICTURES
.............................................................................................................. 30

T
URN
-O
N FROM
I
NPUT
V
OLTAGE
,

S
LOW
S
TART
(-S3)

U
NITS
...................................................................................... 31

T
URN
-O
N FROM
I
NPUT
V
OLTAGE
P
ICTURES
.............................................................................................................. 32

T
URN
-O
N FROM
C
ONTROL
....................................................................................................................................... 33

T
URN
-O
N FROM
C
ONTROL
P
ICTURES
....................................................................................................................... 33

T
URN
-O
FF FROM
C
ONTROL
...................................................................................................................................... 34

OUTPUT SEQUENCING PROTECTION ................................................................................................................. 34

S
EQUENCING
P
ICTURES
........................................................................................................................................... 35

INPUT INRUSH CURRENT ...................................................................................................................................... 37

INPUT TURN-ON CHARACTERISTICS .................................................................................................................. 37

C
APACITIVE
L
OAD
L
IMITS
......................................................................................................................................... 37

OUTPUT TRIMMING ................................................................................................................................................ 38

TRIM EQUATIONS ................................................................................................................................................... 38

TRIM LIMITS FOR ALL MODELS........................................................................................................