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DATA SHEET
Product specification
File under Discrete Semiconductors, SC01
1996 Sep 26
DISCRETE SEMICONDUCTORS
BY278
Damper diode
handbook, 2 columns
M3D118
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1996 Sep 26
2
Philips Semiconductors
Product specification
Damper diode
BY278
FEATURES
Glass passivated
High maximum operating
temperature
Low leakage current
Excellent stability
Available in ammo-pack
Also available with preformed leads
for easy insertion.
APPLICATIONS
Damper diode in high frequency
horizontal deflection circuits up to
16 kHz.
DESCRIPTION
Rugged glass package, using a high
temperature alloyed construction.
This package is hermetically sealed
and fatigue free as coefficients of
expansion of all used parts are
matched.
Fig.1 Simplified outline (SOD64) and symbol.
2/3 page (Datasheet)
MAM104
k
a
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134).
ELECTRICAL CHARACTERISTICS
T
j
= 25
°
C; unless otherwise specified.
SYMBOL
PARAMETER
CONDITIONS
MIN.
MAX.
UNIT
V
RSM
non-repetitive peak reverse voltage
1700
V
V
RRM
repetitive peak reverse voltage
1700
V
V
R
continuous reverse voltage
1650
V
I
FWM
working peak forward current
T
amb
= 75
°
C; PCB mounting (see
Fig.4); see Fig.2
5
A
I
FRM
repetitive peak forward current
10
A
I
FSM
non-repetitive peak forward current
t = 10 ms half sinewave;
T
j
= T
j max
prior to surge;
V
R
= V
RRMmax
50
A
T
stg
storage temperature
65
+175
°
C
T
j
junction temperature
65
+150
°
C
SYMBOL
PARAMETER
CONDITIONS
MAX.
UNIT
V
F
forward voltage
I
F
= 5 A; T
j
= T
j max
; see Fig.3
1.4
V
I
F
= 5 A; see Fig.3
1.5
V
I
R
reverse current
V
R
= V
Rmax
; T
j
= 150
°
C
150
µ
A
t
rr
reverse recovery time
when switched from I
F
= 0.5 A to I
R
= 1 A;
measured at I
R
= 0.25 A; see Fig.6
1
µ
s
t
fr
forward recovery time
when switched to I
F
= 5 A in 50 ns;
T
j
= T
j max
; Fig.7
1
µ
s
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1996 Sep 26
3
Philips Semiconductors
Product specification
Damper diode
BY278
THERMAL CHARACTERISTICS
Note
1. Device mounted on an epoxy-glass printed-circuit board, 1.5 mm thick; thickness of Cu-layer
40
µ
m, see Fig.4.
For more information please refer to the
“General Part of Handbook SC01”.
SYMBOL
PARAMETER
CONDITIONS
VALUE
UNIT
R
th j-tp
thermal resistance from junction to tie-point
lead length = 10 mm
25
K/W
R
th j-a
thermal resistance from junction to ambient
note 1
75
K/W
mounted as shown in Fig.5
40
K/W
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1996 Sep 26
4
Philips Semiconductors
Product specification
Damper diode
BY278
GRAPHICAL DATA
Fig.2
Maximum total power dissipation as a
function of working peak forward current.
Solid line: basic high-voltage E/W modulator circuit; see Fig.8.
Dotted line: basic conventional horizontal deflection circuit; see Fig.9.
Curves include power dissipation due to switching losses.
handbook, halfpage
0
5
4
3
2
1
0
MBH407
0.75
0.25
0.50
1.25
1.00
IFWM (A)
Ptot
(W)
Fig.3
Forward current as a function of forward
voltage; maximum values.
Dotted line: T
j
= 150
°
C.
Solid line: T
j
= 25
°
C.
handbook, halfpage
0
2
1
0
MBH408
3
1
2
5
4
VF (V)
IF
(A)
Fig.4 Device mounted on a printed-circuit board.
Dimensions in mm.
handbook, halfpage
MGA200
3
2
7
50
25
50
Fig.5
Mounting with additional printed-circuit
board for heat sink purposes.
Dimensions in mm.
handbook, halfpage
35
30
10
MGA204
25.4
10
3 cm
2
copper
3 cm
2
copper
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1996 Sep 26
5
Philips Semiconductors
Product specification
Damper diode
BY278
Fig.6 Test circuit and reverse recovery time waveform and definition.
Input impedance oscilloscope: 1 M
, 22 pF; t
r
7 ns.
Source impedance: 50
; t
r
15 ns.
handbook, full pagewidth
10
1
50
25 V
DUT
MAM057
+
t rr
0.5
0
0.5
1.0
IF
(A)
IR
(A)
t
0.25
Fig.7 Forward recovery time definition.
handbook, halfpage
t
t fr
10%
IF
t
90%
100%
VF
MGD600
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1996 Sep 26
6
Philips Semiconductors
Product specification
Damper diode
BY278
APPLICATION INFORMATION
For horizontal deflection circuits, two basic applications are shown in Figs 8 and 9.
The maximum allowable total power dissipation for the diode can be calculated from the thermal resistance R
th j-a
and
the difference between T
j max
and T
amb max
in the application. The maximum I
FWM
can then be taken from Fig.2.
The basic application waveforms in Fig.10 relate to the circuit in Fig.8. In the circuit in Fig.9 the forward conduction time
of the diode is shorter, allowing a higher I
FWM
(see Fig.2).
Fig.8
Application in basic high-voltage E/W
modulator circuit.
D1 = BY278.
handbook, halfpage
MBE935
LY
D1
+
(E-W)
horizontal
deflection
transistor
Fig.9
Application in basic horizontal deflection
circuit.
D1 = BY278.
handbook, halfpage
Cf
Cs
LY
D1
MBE934
horizontal
deflection
transistor
Fig.10 Basic application waveforms.
handbook, full pagewidth
T
I F
VR
t p
I FRM
VRRM
I FWM
time
time
MCD430 - 1
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1996 Sep 26
7
Philips Semiconductors
Product specification
Damper diode
BY278
PACKAGE OUTLINE
DEFINITIONS
LIFE SUPPORT APPLICATIONS
These products are not designed for use in life support appliances, devices, or systems where malfunction of these
products can reasonably be expected to result in personal injury. Philips customers using or selling these products for
use in such applications do so at their own risk and agree to fully indemnify Philips for any damages resulting from such
improper use or sale.
Data Sheet Status
Objective specification
This data sheet contains target or goal specifications for product development.
Preliminary specification
This data sheet contains preliminary data; supplementary data may be published later.
Product specification
This data sheet contains final product specifications.
Limiting values
Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one or
more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation
of the device at these or at any other conditions above those given in the Characteristics sections of the specification
is not implied. Exposure to limiting values for extended periods may affect device reliability.
Application information
Where application information is given, it is advisory and does not form part of the specification.
Fig.11 SOD64.
Dimensions in mm.
The marking band indicates the cathode.
handbook, full pagewidth
MBC049
4.5
max
k
a
28 min
28 min
5.0 max
1.35
max