1N4678 Series
500 mW DO-35 Hermetically
Sealed Glass Zener Voltage
Regulators
This is a complete series of 500 mW Zener diodes with limits and
excellent operating characteristics that reflect the superior capabilities
of silicon–oxide passivated junctions. All this in an axial–lead
hermetically sealed glass package that offers protection in all common
environmental conditions.
Specification Features:
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Cathode
Anode
•
Zener Voltage Range – 1.8 V to 27 V
•
ESD Rating of Class 3 (>16 KV) per Human Body Model
•
DO–204AH (DO–35) Package – Smaller than Conventional
DO–204AA Package
•
Double Slug Type Construction
•
Metallurgical Bonded Construction
Mechanical Characteristics:
CASE:
Double slug type, hermetically sealed glass
FINISH:
All external surfaces are corrosion resistant and leads are
AXIAL LEAD
CASE 299
GLASS
MARKING DIAGRAM
L
1N
4x
xx
YWW
readily solderable
MAXIMUM LEAD TEMPERATURE FOR SOLDERING PURPOSES:
230°C, 1/16″ from the case for 10 seconds
POLARITY:
Cathode indicated by polarity band
MOUNTING POSITION:
Any
MAXIMUM RATINGS
(Note 1.)
Rating
Max. Steady State Power Dissipation
@ T
L
≤
75°C, Lead Length = 3/8″
Derate above 75°C
Operating and Storage
Temperature Range
Symbol
P
D
Value
500
4.0
T
J
, T
stg
–65 to
+200
Unit
mW
mW/°C
°C
L
= Assembly Location
1N4xxx = Device Code
=
(See Table Next Page)
Y
= Year
WW
= Work Week
ORDERING INFORMATION
Device
1N4xxx
1N4xxxRL
1N4xxxRL2 *
1N4xxxTA
1N4xxxTA2 *
1N4xxxRR1
{
1N4xxxRR2
}
{
}
Package
Axial Lead
Axial Lead
Axial Lead
Axial Lead
Axial Lead
Axial Lead
Axial Lead
Shipping
3000 Units/Box
5000/Tape & Reel
5000/Tape & Reel
5000/Ammo Pack
5000/Tape & Reel
3000/Tape & Reel
3000/Tape & Reel
1. Some part number series have lower JEDEC registered ratings.
* The “2” suffix refers to 26 mm tape spacing.
Polarity band
up
with cathode lead off first
Polarity band
down
with cathode lead off first
Devices listed in
bold, italic
are ON Semiconductor
Preferred
devices.
Preferred
devices are recommended
choices for future use and best overall value.
©
Semiconductor Components Industries, LLC, 2001
1
May, 2001 – Rev. 1
Publication Order Number:
1N4678/D
1N4678 Series
Low level oxide passivated zener diodes for applications
requiring extremely low operating currents, low leakage,
and sharp breakdown voltage.
ELECTRICAL CHARACTERISTICS
(T
A
= 25°C unless
otherwise noted, V
F
= 1.5 V Max @ I
F
= 100 mA for all types)
Symbol
V
Z
I
ZT
DV
Z
I
ZM
I
R
V
R
I
F
V
F
Parameter
Reverse Zener Voltage @ I
ZT
Reverse Current
Reverse Zener Voltage Change
Maximum Zener Current
Reverse Leakage Current @ V
R
Breakdown Voltage
Forward Current
Forward Voltage @ I
F
V
Z
V
R
I
R
V
F
I
ZT
V
I
I
F
Zener Voltage Regulator
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2
1N4678 Series
ELECTRICAL CHARACTERISTICS
(T
L
= 30°C unless otherwise noted, V
F
= 1.5 V Max @ I
F
= 100 mA for all types)
Zener Voltage
(Note 3.)
Device
(Note 2.)
1N4678
1N4679
1N4680
1N4681
1N4682
1N4683
1N4684
1N4685
1N4686
1N4687
Device
Marking
1N4678
1N4679
1N4680
1N4681
1N4682
1N4683
1N4684
1N4685
1N4686
1N4687
V
Z
(Volts)
Min
1.71
1.9
2.09
2.28
2.565
2.85
3.135
3.42
3.705
4.085
Nom
1.8
2.0
2.2
2.4
2.7
3.0
3.3
3.6
3.9
4.3
Max
1.89
2.1
2.31
2.52
2.835
3.15
3.465
3.78
4.095
4.515
@ I
ZT
mA
50
50
50
50
50
50
50
50
50
50
Leakage Current
(Note 4.)
I
R
@ V
R
µA
Max
7.5
5
5
2
1
0.8
7.5
7.5
5.0
4.0
Volts
1
1
1
1
1
1
1.5
2
2
2
I
ZM
(Note 5.)
mA
120
110
100
95
90
85
80
75
70
65
DV
Z
(Note 6.)
Volts
0.7
0.7
0.75
0.8
0.85
0.9
0.95
0.95
0.97
0.99
1N4688
1N4689
1N4690
1N4691
1N4692
1N4693
1N4694
1N4695
1N4696
1N4697
1N4698
1N4699
1N4700
1N4701
1N4702
1N4703
1N4704
1N4705
1N4707
1N4711
1N4688
1N4689
1N4690
1N4691
1N4692
1N4693
1N4694
1N4695
1N4696
1N4697
1N4698
1N4699
1N4700
1N4701
1N4702
1N4703
1N4704
1N4705
1N4707
1N4711
4.465
4.845
5.32
5.89
6.46
7.125
7.79
8.265
8.645
9.5
10.45
11.4
12.35
13.3
14.25
15.2
16.15
17.1
19
25.65
4.7
5.1
5.6
6.2
6.8
7.5
8.2
8.7
9.1
10
11
12
13
14
15
16
17
18
20
27
4.935
5.355
5.88
6.51
7.14
7.875
8.61
9.135
9.555
10.5
11.55
12.6
13.65
14.7
15.75
16.8
17.85
18.9
21
28.35
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
50
10
10
10
10
10
10
1
1
1
1
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.05
0.01
0.01
3
3
4
5
5.1
5.7
6.2
6.6
6.9
7.6
8.4
9.1
9.8
10.6
11.4
12.1
12.9
13.6
15.2
20.4
60
55
50
45
35
31.8
29
27.4
26.2
24.8
21.6
20.4
19
17.5
16.3
15.4
14.5
13.2
11.9
8.8
0.99
0.97
0.96
0.95
0.9
0.75
0.5
0.1
0.08
0.1
0.11
0.12
0.13
0.14
0.15
0.16
0.17
0.18
0.2
0.27
2.
TOLERANCE AND TYPE NUMBER DESIGNATION (V
Z
)
The type numbers listed have a standard tolerance of
±5%
on the nominal zener voltage.
3.
ZENER VOLTAGE (V
Z
) MEASUREMENT
The zener voltage is measured with the device junction in the thermal equilibrium at the lead temperature (T
L
) at 30°C
±
1°C and 3/8″ lead
length.
4.
REVERSE LEAKAGE CURRENT (I
R
)
Reverse leakage currents are guaranteed and measured at V
R
shown on the table.
5.
MAXIMUM ZENER CURRENT RATINGS (I
ZM
)
Maximum zener current ratings are based on maximum zener voltage of the individual units and JEDEC 250 mW rating.
6.
MAXIMUM VOLTAGE CHANGE (DV
Z
)
Voltage change is equal to the difference between V
Z
at 100
mA
and at 10
mA.
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3
1N4678 Series
0.7
P
D
, STEADY STATE
POWER DISSIPATION (WATTS)
0.6
0.5
0.4
0.3
0.2
0.1
0
0
20
40
60
80
100
120
140
160
180
200
HEAT
SINKS
3/8"
3/8"
T
L
, LEAD TEMPERATURE (°C)
Figure 1. Steady State Power Derating
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1N4678 Series
θ
JL , JUNCTION TO LEAD THERMAL RESISTANCE (
°
C/W)
APPLICATION NOTE — ZENER VOLTAGE
Since the actual voltage available from a given zener
diode is temperature dependent, it is necessary to determine
junction temperature under any set of operating conditions
in order to calculate its value. The following procedure is
recommended:
Lead Temperature, T
L
, should be determined from:
T
L
=
θ
LA
P
D
+ T
A
.
500
400
L
L
300
200
100
0
2.4-60 V
62-200 V
θ
LA
is the lead-to-ambient thermal resistance (°C/W) and P
D
is the power dissipation. The value for
θ
LA
will vary and
depends on the device mounting method.
θ
LA
is generally 30
to 40°C/W for the various clips and tie points in common use
and for printed circuit board wiring.
The temperature of the lead can also be measured using a
thermocouple placed on the lead as close as possible to the
tie point. The thermal mass connected to the tie point is
normally large enough so that it will not significantly
respond to heat surges generated in the diode as a result of
pulsed operation once steady-state conditions are achieved.
Using the measured value of T
L
, the junction temperature
may be determined by:
T
J
= T
L
+
∆T
JL
.
0
0.2
0.4
0.6
0.8
1
L, LEAD LENGTH TO HEAT SINK (INCH)
Figure 2. Typical Thermal Resistance
1000
7000
5000
2000
1000
700
500
200
100
70
50
20
10
7
5
2
1
0.7
0.5
0.2
0.1
0.07
0.05
0.02
0.01
0.007
0.005
0.002
0.001
3
4
5
6
7
8
9
10
11
12
13
14
15
+25°C
TYPICAL LEAKAGE CURRENT
AT 80% OF NOMINAL
BREAKDOWN VOLTAGE
∆T
JL
is the increase in junction temperature above the lead
temperature and may be found from Figure 2 for dc power:
∆T
JL
=
θ
JL
P
D
.
∆V
=
θ
VZ
T
J
.
θ
VZ
, the zener voltage temperature coefficient, is found
from Figures 4 and 5.
Under high power-pulse operation, the zener voltage will
vary with time and may also be affected significantly by the
zener resistance. For best regulation, keep current
excursions as low as possible.
Surge limitations are given in Figure 7. They are lower
than would be expected by considering only junction
temperature, as current crowding effects cause temperatures
to be extremely high in small spots, resulting in device
degradation should the limits of Figure 7 be exceeded.
I R , LEAKAGE CURRENT (
µ
A)
For worst-case design, using expected limits of I
Z
, limits
of P
D
and the extremes of T
J
(∆T
J
) may be estimated.
Changes in voltage, V
Z
, can then be found from:
+125°C
V
Z
, NOMINAL ZENER VOLTAGE (VOLTS)
Figure 3. Typical Leakage Current
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