LM129/LM329
Precision Reference
General Description
The LM129 and LM329 family are precision multi-current
temperature-compensated 6.9V zener references with dy-
namic impedances a factor of 10 to 100 less than discrete di-
odes. Constructed in a single silicon chip, the LM129 uses
active circuitry to buffer the internal zener allowing the de-
vice to operate over a 0.5 mA to 15 mA range with virtually
no change in performance. The LM129 and LM329 are avail-
able with selected temperature coefficients of 0.001, 0.002,
0.005 and 0.01%/C. These references also have excellent
long term stability and low noise.
A new subsurface breakdown zener used in the LM129 gives
lower noise and better long-term stability than conventional
IC zeners. Further the zener and temperature compensating
transistor are made by a planar process so they are immune
to problems that plague ordinary zeners. For example, there
is virtually no voltage shift in zener voltage due to tempera-
ture cycling and the device is insensitive to stress on the
leads.
The LM129 can be used in place of conventional zeners with
improved performance. The low dynamic impedance simpli-
fies biasing and the wide operating current allows the re-
placement of many zener types.
The LM129 is packaged in a 2-lead TO-46 package and is
rated for operation over a -55C to +125C temperature
range. The LM329 for operation over 0C to 70C is available
in both a hermetic TO-46 package and a TO-92 epoxy pack-
age.
Features
n
0.6 mA to 15 mA operating current
n
0.6
dynamic impedance at any current
n
Available with temperature coefficients of 0.001%/C
n
7V wideband noise
n
5% initial tolerance
n
0.002% long term stability
n
Low cost
n
Subsurface zener
Connection Diagrams
Metal Can Package (T046)
DS005714-6
Pin 2 is electrically connected to case
Bottom View
Order Number LM129AH, LM129AH/883, LM129BH,
LM129BH/883, LM129CH, LM329AH, LM329BH,
LM329CH or LM329DH
See NS Package H02A
Plastic Package (TO-92)
DS005714-4
Bottom View
Order Number LM329BZ,
LM329CZ or LM329DZ
See NS Package Z03A
March 2000
LM129/LM329
Precision
Reference
2000 National Semiconductor Corporation
DS005714
www.national.com
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
(Note 3)
Reverse Breakdown Current
30 mA
Forward Current
2 mA
Operating Temperature Range
LM129
-55C to +125C
LM329
0C to +70C
Storage Temperature Range
-55C to +150C
Soldering Information
TO-92 package: 10 sec.
260C
TO-46 package: 10 sec.
300C
Electrical Characteristics
(Note 2)
LM129A, B, C
LM329A, B, C, D
Parameter
Conditions
Units
Min
Typ
Max
Min
Typ
Max
Reverse Breakdown Voltage
T
A
= 25C,
0.6 mA
I
R
15 mA
6.7
6.9
7.2
6.6
6.9
7.25
V
Reverse Breakdown Change
T
A
= 25C,
with Current (Note 4)
0.6 mA
I
R
15 mA
9
14
9
20
mV
Reverse Dynamic Impedance
T
A
= 25C, I
R
= 1 mA
0.6
1
0.8
2
(Note 4)
RMS Noise
T
A
= 25C,
10 Hz
F
10 kHz
7
20
7
100
V
Long Term Stability
T
A
= 45C
0.1C,
(1000 hours)
I
R
= 1 mA
0.3%
20
20
ppm
Temperature Coefficient
I
R
= 1 mA
LM129A, LM329A
6
10
6
10
ppm/C
LM129B, LM329B
15
20
15
20
ppm/C
LM129C, LM329C
30
50
30
50
ppm/C
LM329D
50
100
ppm/C
Change In Reverse Breakdown
1 mA
I
R
15 mA
1
1
ppm/C
Temperature Coefficient
Reverse Breakdown Change
1 mA
I
R
15 mA
12
12
mV
with Current
Reverse Dynamic Impedance
1 mA
I
R
15 mA
0.8
1
Note 1: "Absolute Maximum Ratings" indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits.
Note 2: These specifications apply for -55C
T
A
+125C for the LM129 and 0C
T
A
+70C for the LM329 unless otherwise specified. The maximum junction
temperature for an LM129 is 150C and LM329 is 100C. For operating at elevated temperature, devices in TO-46 package must be derated based on a thermal re-
sistance of 440C/W junction to ambient or 80C/W junction to case. For the TO-92 package, the derating is based on 180C/W junction to ambient with 0.4" leads
from a PC board and 160C/W junction to ambient with 0.125" lead length to a PC board.
Note 3: Refer to RETS129H for LM129 family military specifications.
Note 4: These changes are tested on a pulsed basis with a low duty-cycle. For changes versus temperature, compute in terms of tempco.
LM129/LM329
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