LM136-2.5,LM236-2.5,LM336-2.5
LM136-2.5/LM236-2.5/LM336-2.5V Reference Diode
Literature Number: SNVS749D
LM136-2.5/LM236-2.5/LM336-2.5V
Reference Diode
General Description
The LM136-2.5/LM236-2.5 and LM336-2.5 integrated cir-
cuits are precision 2.5V shunt regulator diodes. These
monolithic IC voltage references operate as a low-
temperature-coefficient 2.5V zener with 0.2dynamic im-
pedance. A third terminal on the LM136-2.5 allows the refer-
ence voltage and temperature coefficient to be trimmed
easily.
The LM136-2.5 series is useful as a precision 2.5V low
voltage reference for digital voltmeters, power supplies or op
amp circuitry. The 2.5V make it convenient to obtain a stable
reference from 5V logic supplies. Further, since the LM136-
2.5 operates as a shunt regulator, it can be used as either a
positive or negative voltage reference.
The LM136-2.5 is rated for operation over −55˚C to +125˚C
while the LM236-2.5 is rated over a −25˚C to +85˚C tem-
perature range.
The LM336-2.5 is rated for operation over a 0˚C to +70˚C
temperature range. See the connection diagrams for avail-
able packages.
Features
nLow temperature coefficient
nWide operating current of 400 µA to 10 mA
n0.2dynamic impedance
n±1% initial tolerance available
nGuaranteed temperature stability
nEasily trimmed for minimum temperature drift
nFast turn-on
Connection Diagrams
TO-92
Plastic Package
00571508
Bottom View
Order Number LM336Z-2.5 or LM336BZ-2.5
See NS Package Number Z03A
TO-46
Metal Can Package
00571520
Bottom View
Order Number LM136H-2.5,
LM136H-2.5/883, LM236H-2.5,
or LM236AH-2.5
See NS Package Number H03H
SO Package
00571512
Top View
Order Number LM236M-2.5,
LM236AM-2.5, LM336M-2.5
or LM336BM-2.5
See NS Package Number M08A
June 2005
LM136-2.5/LM236-2.5/LM336-2.5V Reference Diode
© 2005 National Semiconductor Corporation DS005715 www.national.com
Typical Applications
2.5V Reference
00571509
2.5V Reference with Minimum
Temperature Coefficient
00571510
Adjust to 2.490V
*Any silicon signal diode
Wide Input Range Reference
00571511
LM136-2.5/LM236-2.5/LM336-2.5V
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Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Reverse Current 15 mA
Forward Current 10 mA
Storage Temperature −60˚C to +150˚C
Operating Temperature Range (Note 2)
LM136 −55˚C to +150˚C
LM236 −25˚C to +85˚C
LM336 0˚C to +70˚C
Soldering Information
TO-92 Package (10 sec.) 260˚C
TO-46 Package (10 sec.) 300˚C
SO Package
Vapor Phase (60 sec.) 215˚C
Infrared (15 sec.) 220˚C
See AN-450 “Surface Mounting Methods and Their Effect
on Product Reliability” (Appendix D) for other methods of
soldering surface mount devices.
Electrical Characteristics (Note 3)
LM136A-2.5/LM236A-2.5 LM336B-2.5
Parameter Conditions LM136-2.5/LM236-2.5 LM336-2.5 Units
Min Typ Max Min Typ Max
Reverse Breakdown
Voltage
T
A
=25˚C, I
R
=1 mA
LM136, LM236, LM336 2.440 2.490 2.540 2.390 2.490 2.590 V
LM136A, LM236A, LM336B 2.465 2.490 2.515 2.440 2.490 2.540 V
Reverse Breakdown
Change
T
A
=25˚C, 2.6 6 2.6 10 mV
With Current 400 µAI
R
10 mA
Reverse Dynamic
Impedance
T
A
=25˚C, I
R
=1 mA, f = 100 Hz 0.2 0.6 0.2 1
Temperature Stability V
R
Adjusted to 2.490V
(Note 4) I
R
=1 mA, Figure 2
0˚CT
A
70˚C (LM336) 1.8 6 mV
−25˚CT
A
+85˚C 3.5 9 mV
(LM236H, LM236Z)
−25˚C T
A
+85˚C (LM236M) 7.5 18 mV
−55˚CT
A
+125˚C (LM136) 12 18 mV
Reverse Breakdown
Change
400 µAI
R
10 mA 3 10 3 12 mV
With Current
Reverse Dynamic
Impedance
I
R
=1 mA 0.4 1 0.4 1.4
Long Term Stability T
A
=25˚C ±0.1˚C, I
R
=1 mA, 20 20 ppm
t = 1000 hrs
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device
beyond its specified operating conditions.
Note 2: For elevated temperature operation, Tjmax is:
LM136 150˚C
LM236 125˚C
LM336 100˚C
Thermal Resistance TO-92 TO-46 SO-8
θ
ja
(Junction to Ambient) 180˚C/W (0.4" leads) 440˚C/W 165˚C/W
170˚C/W (0.125" lead)
θ
ja
(Junction to Case) n/a 80˚C/W n/a
LM136-2.5/LM236-2.5/LM336-2.5V
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Electrical Characteristics (Note 3) (Continued)
Note 3: Unless otherwise specified, the LM136-2.5 is specified from −55˚C TA+125˚C, the LM236-2.5 from −25˚C TA+85˚C and the LM336-2.5 from 0˚C
TA+70˚C.
Note 4: Temperature stability for the LM336 and LM236 family is guaranteed by design. Design limits are guaranteed (but not 100% production tested) over the
indicated temperature and supply voltage ranges. These limits are not used to calculate outgoing quality levels. Stability is defined as the maximum change in Vref
from 25˚C to TA(min) or TA(max).
LM136-2.5/LM236-2.5/LM336-2.5V
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Typical Performance Characteristics
Reverse Voltage Change Zener Noise Voltage
00571521 00571522
Dynamic Impedance Response Time
00571523 00571524
Reverse Characteristics Forward Characteristics
00571525 00571526
LM136-2.5/LM236-2.5/LM336-2.5V
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Typical Performance
Characteristics (Continued)
Temperature Drift
00571527
Application Hints
The LM136 series voltage references are much easier to use
than ordinary zener diodes. Their low impedance and wide
operating current range simplify biasing in almost any circuit.
Further, either the breakdown voltage or the temperature
coefficient can be adjusted to optimize circuit performance.
Figure 1 shows an LM136 with a 10k potentiometer for
adjusting the reverse breakdown voltage. With the addition
of R1 the breakdown voltage can be adjusted without affect-
ing the temperature coefficient of the device. The adjustment
range is usually sufficient to adjust for both the initial device
tolerance and inaccuracies in buffer circuitry.
If minimum temperature coefficient is desired, two diodes
can be added in series with the adjustment potentiometer as
shown in Figure 2. When the device is adjusted to 2.490V
the temperature coefficient is minimized. Almost any silicon
signal diode can be used for this purpose such as a 1N914,
1N4148 or a 1N457. For proper temperature compensation
the diodes should be in the same thermal environment as
the LM136. It is usually sufficient to mount the diodes near
the LM136 on the printed circuit board. The absolute resis-
tance of R1 is not critical and any value from 2k to 20k will
work.
00571528
FIGURE 1. LM136 With Pot for Adjustment
of Breakdown Voltage
(Trim Range = ±120 mV typical)
00571529
FIGURE 2. Temperature Coefficient Adjustment
(Trim Range = ±70 mV typical)
LM136-2.5/LM236-2.5/LM336-2.5V
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Application Hints (Continued)
Low Cost 2 Amp Switching Regulator
00571505
*L1 60 turns #16 wire on Arnold Core A-254168-2
Efficiency 80%
Precision Power Regulator with Low Temperature Coefficient
00571513
5V Crowbar
00571514
Trimmed 2.5V Reference with
Temperature Coefficient Independent
of Breakdown Voltage
00571515
*Does not affect temperature coefficient
LM136-2.5/LM236-2.5/LM336-2.5V
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Application Hints (Continued)
Adjustable Shunt Regulator
00571506
Linear Ohmmeter
00571516
LM136-2.5/LM236-2.5/LM336-2.5V
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Application Hints (Continued)
Op Amp with Output Clamped
00571517
Bipolar Output Reference
00571518
2.5V Square Wave Calibrator
00571519
5V Buffered Reference
00571530
Low Noise Buffered Reference
00571531
LM136-2.5/LM236-2.5/LM336-2.5V
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Schematic Diagram
00571501
LM136-2.5/LM236-2.5/LM336-2.5V
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Physical Dimensions inches (millimeters)
unless otherwise noted
Order Number LM136H-2.5, LM136H-2.5/883, LM236H-2.5, LM136AH-2.5, LM136AH-2.5/883 or LM236AH-2.5
NS Package Number H03H
Small Outline (SO) Package (M)
Order Number LM236M-2.5, LM236AM-2.5, LM336M-2.5 or LM336BM-2.5
NS Package Number M08A
LM136-2.5/LM236-2.5/LM336-2.5V
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Physical Dimensions inches (millimeters) unless otherwise noted (Continued)
TO-92 Plastic Package (Z)
Order Number LM336Z-2.5 or LM336BZ-2.5
NS Package Number Z03A
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
For the most current product information visit us at www.national.com.
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LM136-2.5/LM236-2.5/LM336-2.5V Reference Diode
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