LM136-2.5
LM136-2.5 LM236-2.5 LM336-2.5V Reference Diode
Literature Number: SNVS749E
LM136-2.5
LM236-2.5
LM336-2.5V
February 27, 2009
Reference Diode
General Description
The LM136-2.5/LM236-2.5 and LM336-2.5 integrated circuits
are precision 2.5V shunt regulator diodes. These monolithic
IC voltage references operate as a low-temperature-coeffi-
cient 2.5V zener with 0.2Ω dynamic impedance. A third ter-
minal on the LM136-2.5 allows the reference voltage and
temperature coefficient to be trimmed easily.
The LM136-2.5 series is useful as a precision 2.5V low volt-
age reference for digital voltmeters, power supplies or op amp
circuitry. The 2.5V make it convenient to obtain a stable ref-
erence from 5V logic supplies. Further, since the LM136-2.5
operates as a shunt regulator, it can be used as either a pos-
itive 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 temper-
ature 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
Low temperature coefficient
Wide operating current of 400 μA to 10 mA
0.2Ω dynamic impedance
±1% initial tolerance available
Guaranteed temperature stability
Easily trimmed for minimum temperature drift
Fast turn-on
Connection Diagrams
TO-92
Plastic Package
571508
Bottom View
Order Number LM336Z-2.5 or LM336BZ-2.5
See NS Package Number Z03A
TO-46
Metal Can Package
571520
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
571512
Top View
Order Number LM236M-2.5,
LM236AM-2.5, LM336M-2.5
or LM336BM-2.5
See NS Package Number M08A
© 2009 National Semiconductor Corporation 5715 www.national.com
LM136-2.5/LM236-2.5/LM336-2.5V Reference Diode
Typical Applications
2.5V Reference
571509
2.5V Reference with Minimum
Temperature Coefficient
571510
Adjust to 2.490V
*Any silicon signal diode
Wide Input Range Reference
571511
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LM136-2.5/LM236-2.5/LM336-2.5V
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
TA=25°C, IR=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
TA=25°C, 2.6 6 2.6 10 mV
With Current 400 μAIR10 mA
Reverse Dynamic
Impedance
TA=25°C, IR=1 mA, f = 100 Hz 0.2 0.6 0.2 1 Ω
Temperature Stability VR Adjusted to 2.490V
(Note 4) IR=1 mA, Figure 2
0°CTA70°C (LM336) 1.8 6 mV
−25°CTA+85°C 3.5 9 mV
(LM236H, LM236Z)
−25°C TA +85°C (LM236M) 7.5 18 mV
−55°CTA+125°C (LM136) 12 18 mV
Reverse Breakdown
Change
400 μAIR10 mA 3 10 3 12 mV
With Current
Reverse Dynamic
Impedance
IR=1 mA 0.4 1 0.4 1.4 Ω
Long Term Stability TA=25°C ±0.1°C, IR=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, Tj max is:
LM136 150°C
LM236 125°C
LM336 100°C
Thermal Resistance TO-92 TO-46 SO-8
θja (Junction to Ambient) 180°C/W (0.4″ leads) 440°C/W 165°C/W
170°C/W (0.125″ lead)
θja (Junction to Case) n/a 80°C/W n/a
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LM136-2.5/LM236-2.5/LM336-2.5V
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).
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LM136-2.5/LM236-2.5/LM336-2.5V
Typical Performance Characteristics
Reverse Voltage Change
571521
Zener Noise Voltage
571522
Dynamic Impedance
571523
Response Time
571524
Reverse Characteristics
571525
Forward Characteristics
571526
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LM136-2.5/LM236-2.5/LM336-2.5V
Temperature Drift
571527
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 co-
efficient can be adjusted to optimize circuit performance.
Figure 1 shows an LM136 with a 10k potentiometer for ad-
justing the reverse breakdown voltage. With the addition of
R1 the breakdown voltage can be adjusted without affecting
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 sig-
nal 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 resistance
of R1 is not critical and any value from 2k to 20k will work.
571528
FIGURE 1. LM136 With Pot for Adjustment
of Breakdown Voltage
(Trim Range = ±120 mV typical)
571529
FIGURE 2. Temperature Coefficient Adjustment
(Trim Range = ±70 mV typical)
Low Cost 2 Amp Switching Regulator
571505
*L1 60 turns #16 wire on Arnold Core A-254168-2
Efficiency 80%
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LM136-2.5/LM236-2.5/LM336-2.5V
Precision Power Regulator with Low Temperature Coefficient
571513
5V Crowbar
571514
Trimmed 2.5V Reference with
Temperature Coefficient Independent
of Breakdown Voltage
571515
*Does not affect temperature coefficient
Adjustable Shunt Regulator
571506
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LM136-2.5/LM236-2.5/LM336-2.5V
Linear Ohmmeter
571516
Op Amp with Output Clamped
571517
Bipolar Output Reference
571518
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LM136-2.5/LM236-2.5/LM336-2.5V
2.5V Square Wave Calibrator
571519
5V Buffered Reference
571530
Low Noise Buffered Reference
571531
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LM136-2.5/LM236-2.5/LM336-2.5V
Schematic Diagram
571501
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LM136-2.5/LM236-2.5/LM336-2.5V
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
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LM136-2.5/LM236-2.5/LM336-2.5V
TO-92 Plastic Package (Z)
Order Number LM336Z-2.5 or LM336BZ-2.5
NS Package Number Z03A
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LM136-2.5/LM236-2.5/LM336-2.5V
Notes
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LM136-2.5/LM236-2.5/LM336-2.5V
Notes
LM136-2.5/LM236-2.5/LM336-2.5V Reference Diode
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