1N957B 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:
http://onsemi.com
Cathode
Anode
•
Zener Voltage Range – 6.8 V to 75 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
9x
xB
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
1N9xxB = Device Code
=
(See Table Next Page)
Y
= Year
WW
= Work Week
ORDERING INFORMATION
Device
1N9xxB
1N9xxBRL
1N9xxBRL2 *
1N9xxBRA1
1N9xxBTA
1N9xxBTA2 *
1N9xxBRR1
{
1N9xxBRR2
}
{
}
Package
Axial Lead
Axial Lead
Axial Lead
Axial Lead
Axial Lead
Axial Lead
Axial Lead
Axial Lead
Shipping
3000 Units/Box
5000/Tape & Reel
5000/Tape & Reel
3000/Ammo Pack
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
©
Semiconductor Components Industries, LLC, 2001
1
May, 2001 – Rev. 1
Publication Order Number:
1N957B/D
1N957B Series
ELECTRICAL CHARACTERISTICS
(T
A
= 25°C unless
otherwise noted, V
F
= 1.5 V Max @ I
F
= 200 mA for all types)
Symbol
V
Z
I
ZT
Z
ZT
I
ZK
Z
ZK
I
R
V
R
I
F
V
F
I
ZM
Parameter
Reverse Zener Voltage @ I
ZT
Reverse Current
Maximum Zener Impedance @ I
ZT
Reverse Current
Maximum Zener Impedance @ I
ZK
Reverse Leakage Current @ V
R
Breakdown Voltage
Forward Current
Forward Voltage @ I
F
Maximum DC Zener Current
V
Z
V
R
I
R
V
F
I
ZT
V
I
F
I
Zener Voltage Regulator
ELECTRICAL CHARACTERISTICS
(T
A
= 25°C unless otherwise noted, V
F
= 1.5 V Max @ I
F
= 200 mA for all types)
Zener Voltage
(Note 3.)
Device
(Note 2.)
1N957B
1N958B
1N959B
1N960B
1N961B
1N962B
1N963B
1N964B
1N965B
1N966B
1N967B
1N968B
1N969B
1N970B
1N971B
1N972B
1N973B
1N974B
1N975B
1N978B
1N979B
1N982B
Device
Marking
1N957B
1N958B
1N959B
1N960B
1N961B
1N962B
1N963B
1N964B
1N965B
1N966B
1N967B
1N968B
1N969B
1N970B
1N971B
1N972B
1N973B
1N974B
1N975B
1N978B
1N979B
1N982B
V
Z
(Volts)
Min
6.46
7.125
7.79
8.645
9.5
10.45
11.4
12.35
14.25
15.2
17.1
19
20.9
22.8
25.65
28.5
31.35
34.2
37.05
48.45
53.2
71.25
Nom
6.8
7.5
8.2
9.1
10
11
12
13
15
16
18
20
22
24
27
30
33
36
39
51
56
75
Max
7.14
7.875
8.61
9.555
10.5
11.55
12.6
13.65
15.75
16.8
18.9
21
23.1
25.2
28.35
31.5
34.65
37.8
40.95
53.55
58.8
78.75
@ I
ZT
mA
18.5
16.5
15
14
12.5
11.5
10.5
9.5
8.5
7.8
7.0
6.2
5.6
5.2
4.6
4.2
3.8
3.4
3.2
2.5
2.2
1.7
Zener Impedance
(Note 4.)
Z
ZT
@ I
ZT
W
4.5
5.5
6.5
7.5
8.5
9.5
11.5
13
16
17
21
25
29
33
41
49
58
70
80
125
150
270
Z
ZK
@ I
ZK
W
700
700
700
700
700
700
700
700
700
700
750
750
750
750
750
1000
1000
1000
1000
1500
2000
2000
mA
1.0
0.5
0.5
0.5
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
0.25
µA
150
75
50
25
10
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
Leakage Current
I
R
@ V
R
Volts
5.2
5.7
6.2
6.9
7.6
8.4
9.1
9.9
11.4
12.2
13.7
15.2
16.7
18.2
20.6
22.8
25.1
27.4
29.7
38.8
42.6
56
I
ZM
(Note 5.)
mA
47
42
38
35
32
28
26
24
21
19
17
15
14
13
11
10
9.2
8.5
7.8
5.9
5.4
4.1
2.
TOLERANCE AND VOLTAGE DESIGNATION
Tolerance designation – Device tolerance of
±5%
is indicated by a “B” suffix.
3.
ZENER VOLTAGE (V
Z
) MEASUREMENT
Nominal 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.
ZENER IMPEDANCE (Z
Z
) DERIVATION
Z
ZT
and Z
ZK
are measured by dividing the ac voltage drop across the device by the ac current applied. The specified limits are for I
Z(ac)
=
0.1 I
Z(dc)
with the ac frequency = 60 Hz.
5.
MAXIMUM ZENER CURRENT RATINGS (I
ZM
)
Values shown are based on the JEDEC rating of 400 mW where the actual zener voltage (V
Z
) is known at the operating point, the maximum
zener current may be increased and is limited by the derating curve.
http://onsemi.com
2
1N957B 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
http://onsemi.com
3
1N957B 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
http://onsemi.com
4
1N957B Series
TEMPERATURE COEFFICIENTS
(–55°C to +150°C temperature range; 90% of the units are in the ranges indicated.)
θV
Z , TEMPERATURE COEFFICIENT (mV/
°C)
θV
Z , TEMPERATURE COEFFICIENT (mV/
°C)
+12
+10
+8
+6
+4
+2
0
-2
-4
2
3
4
5
6
7
8
9
V
Z
, ZENER VOLTAGE (VOLTS)
10
11
12
RANGE
V
Z
@ I
ZT
(NOTE 2)
100
70
50
30
20
10
7
5
3
2
1
10
20
30
50
V
Z
, ZENER VOLTAGE (VOLTS)
70
100
RANGE
V
Z
@ I
Z
(NOTE 2)
Figure 4a. Range for Units to 12 Volts
Figure 4b. Range for Units 12 to 100 Volts
θV
Z , TEMPERATURE COEFFICIENT (mV/
°C)
θV
Z , TEMPERATURE COEFFICIENT (mV/
°C)
200
180
160
140
120
100
V
Z
@ I
ZT
(NOTE 2)
120
130
140
150
160
170
180
190
200
+6
+4
+2
0
-2
-4
V
Z
@ I
Z
T
A
= 25°C
20 mA
0.01 mA
1 mA
NOTE: BELOW 3 VOLTS AND ABOVE 8 VOLTS
NOTE:
CHANGES IN ZENER CURRENT DO NOT
NOTE:
AFFECT TEMPERATURE COEFFICIENTS
3
4
5
6
7
8
V
Z
, ZENER VOLTAGE (VOLTS)
V
Z
, ZENER VOLTAGE (VOLTS)
Figure 4c. Range for Units 120 to 200 Volts
Figure 5. Effect of Zener Current
1000
500
C, CAPACITANCE (pF)
200
100
50
20
10
5
2
1
1
2
5
10
20
50% OF
V
Z
BIAS
0 V BIAS
T
A
= 25°C
100
70
50
C, CAPACITANCE (pF)
30
20
10
7
5
3
2
1
T
A
= 25°C
0 BIAS
1 V BIAS
1 VOLT BIAS
50% OF V
Z
BIAS
50
100
120
140
160
180
190
200
220
V
Z
, ZENER VOLTAGE (VOLTS)
V
Z
, ZENER VOLTAGE (VOLTS)
Figure 6a. Typical Capacitance 2.4–100 Volts
Figure 6b. Typical Capacitance 120–200 Volts
http://onsemi.com
5